WO2023121346A1 - Apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate - Google Patents

Abstract

The present invention relates to an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate. According to the present invention, there is provided the apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, comprising a dissolving unit, a first solid-phase precipitate producing unit, and a sodium bicarbonate producing unit, wherein, in the dissolving unit, a sodium sulfate aqueous solution in which industrial by-products containing sodium sulfate are dissolved in water is prepared; in the first solid-phase precipitate producing unit, calcium sulfate is produced and recovered by a reaction between sulfate ions in the sodium sulfate aqueous solution and calcium ions provided from a source of calcium; and in the sodium bicarbonate producing unit, sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate in the first solid-phase precipitate producing unit. By the production apparatus of the present invention, the industrial by-products containing sodium sulfate can be processed at low cost, and expensive sodium bicarbonate can be efficiently recovered.

Description

Apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate

The present invention relates to an apparatus for producing sodium bicarbonate from an industrial by-product containing sodium sulfate. More specifically, the present invention relates to an apparatus for producing sodium bicarbonate and other valuable resources from industrial by-products containing sodium sulfate.

Demand for the desulfurization (DeSOx) process in flue gas is increasing due to the strengthening of environmental standards such as fine dust, and Ca(OH) ₂ , CaO, and CaCO ₃ are mainly used for desulfurization.

However, in order to satisfy more stringent standards, a desulfurization process using Na-based sodium bicarbonate (NaHCO ₃ , sodium bicarbonate) is gradually expanding. Na-based sodium bicarbonate has higher desulfurization efficiency than Ca-based desulfurization agents, but is more expensive than Ca-based desulfurization agents, and Na ₂ SO ₄ is finally produced. Waste Ca-based desulfurization agent is CaSO ₄ , which can be reused as a raw material for gypsum. However, Na ₂ SO ₄ produced by Na-based desulfurization agent has no large amount of use, contains impurities, etc., and has high water solubility, so it is difficult to landfill. It is difficult, so the waste disposal costs are high. Therefore, it is required to develop a technology for recycling waste desulfurization agent containing Na ₂ SO ₄ to reduce the cost of waste treatment and to improve the economic feasibility of recovering sodium bicarbonate through regeneration of sodium sulfate.

U.S. Patent No. 5,830,422 discloses the preparation of sodium bicarbonate, sodium carbonate and ammonium sulfate from sodium sulfate. The US patent uses ammonia to produce NaHCO ₃ from desulfurization waste. In addition, the process itself is complicated because ammonia is used to dissolve CO ₂ or an additional process for recovering ammonia is included, and Ca(OH) ₂ is used to treat the waste liquid of NaHCO ₃ produced from Na ₂ SO ₄ . It is different from the process in the manufacturing apparatus of the present invention in that it is used for the purpose.

(Prior art literature)

(Patent Document 1) US Patent No. 5,830,422

The present invention relates to an apparatus capable of effectively producing sodium bicarbonate and other valuable resources from industrial by-products containing sodium sulfate.

In the first aspect, as an apparatus for producing sodium hydrogen carbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generation unit and a sodium hydrogen carbonate generation unit,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; and

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit.

In the second aspect, as an apparatus for producing sodium hydrogen carbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generation unit, and a sodium hydrogen carbonate generation unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, it is sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit. Including a second cycle that becomes,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the sodium bicarbonate generating unit, after recovering calcium sulfate in the first solid precipitate generating unit, carbon dioxide is dissolved in the remaining filtrate to generate and recover sodium bicarbonate, and the filtrate remaining after recovering sodium bicarbonate is dissolved in the dissolved carbon dioxide. recycled into wealth,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, sulfate ions and bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate react with calcium ions provided by a calcium source to produce and recover calcium sulfate and calcium carbonate;

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate and calcium carbonate in the first solid precipitate generating unit.

In the third aspect, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and a sodium hydrogen carbonate generating unit,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit;

In the sodium bicarbonate generating unit, after the recovery of calcium carbonate in the second solid precipitate generating unit, carbon dioxide is dissolved in the remaining filtrate to produce and recover sodium bicarbonate, a manufacturing apparatus is provided.

In the fourth aspect, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and sodium bicarbonate generating unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, the dissolving unit, the first solid precipitate generating unit, and the second solid precipitate generating unit and hydrogen carbonate Including a second circulation sequentially processed in the sodium generating unit,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the sodium bicarbonate generation unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium sulfate in the first solid precipitate generation unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolution unit. become,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, calcium carbonate is produced and recovered by reacting bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate and calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the filtrate remaining after the recovery of calcium carbonate in the first solid precipitate generating unit and calcium ions provided by a calcium source,

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate in the second solid precipitate generating unit.

In the fifth aspect, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and sodium hydrogen carbonate generating unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, it is sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit. Including a second cycle that becomes,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit;

In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium carbonate in the second solid precipitate generating unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolving unit. become,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, calcium sulfate and calcium carbonate are generated and recovered by reacting calcium ions provided by a calcium supply source with sulfate ions and bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate;

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate and calcium carbonate in the first solid precipitate generating unit.

In the sixth point of view,

An apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit, and a sodium hydrogen carbonate generating unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit and sodium bicarbonate It includes a second cycle that is sequentially processed in the generating unit,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit;

In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the removal of calcium carbonate in the second solid precipitate producing unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolving unit. become,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, calcium carbonate is produced and recovered by reacting bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate and calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the filtrate remaining after the recovery of calcium carbonate in the first solid precipitate generating unit and calcium ions provided by a calcium source,

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the second solid precipitate generating unit.

In the seventh aspect, any one of the second aspect and the fourth to sixth aspect, wherein the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the second circulation is recycled back to the dissolving unit. A manufacturing apparatus according to is provided.

In the eighth aspect, the calcium source is at least one selected from the group consisting of Ca ²⁺ -containing waste, calcium oxide and calcium hydroxide, and a manufacturing apparatus according to any one of the first to sixth aspects is provided.

In the ninth aspect, a manufacturing apparatus according to any one of the first to sixth aspects is provided in which industrial by-products containing sodium sulfate are dissolved in water or a filtrate at a temperature of 10 ° C to 50 ° C in the dissolution unit. .

In the tenth aspect, the production of calcium sulfate, calcium sulfate and calcium carbonate or calcium carbonate in the first solid precipitate generating unit is carried out at a temperature of 25 ℃ to 45 ℃, a manufacturing apparatus is provided.

In the eleventh aspect, the production of calcium carbonate or calcium sulfate in the second solid precipitate generating unit is carried out at a temperature of 25 ℃ to 45 ℃, the manufacturing apparatus according to any one of the third to sixth aspects is provided do.

In the twelfth aspect, the production of sodium hydrogen carbonate in the sodium hydrogen carbonate generating unit is performed at a temperature of 25 ° C to 45 ° C, the manufacturing apparatus according to any one of the first to sixth aspects is provided.

In the thirteenth aspect, the manufacturing apparatus according to any one of the first to sixth aspects, wherein the industrial by-product containing sodium sulfate is a waste desulfurization agent or a sulfuric acid neutralized waste liquid, is provided.

In the apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate (hereinafter also referred to as 'manufacturing apparatus') of the present invention, industrial by-products containing sodium sulfate are stably treated, and sodium bicarbonate (NaHCO ₃ ) as well as calcium sulphate (CaSO ₄ , gypsum) and calcium carbonate (CaCO ₃ ) are recovered. In addition, CO ₂ is fixed according to the formation of calcium carbonate (CaCO ₃ ), contributing to CO ₂ reduction. Regenerated sodium bicarbonate (NaHCO ₃ ) can be used as a desulfurization agent in the desulfurization process, and calcium sulfate (CaSO ₄ ) and/or calcium carbonate (CaCO ₃ ) can be used as a building material. The manufacturing apparatus of the present invention produces less wastewater. In addition, since the manufacturing apparatus of the present invention does not use a substance (eg, ammonia) for dissolving CO ₂ , sodium bicarbonate, calcium sulfate, and calcium carbonate are efficiently recovered from industrial by-products containing sodium sulfate through a simple process. In addition, industrial by-products containing sodium sulfate can be treated at a low cost and expensive sodium bicarbonate is recovered, which is economical.

1 is a view schematically showing a manufacturing apparatus and a process in the manufacturing apparatus according to the present invention.

2 is a view showing the manufacturing apparatus according to the present invention in more detail.

3 is a graph showing the solubility of sodium sulfate (Na ₂ SO ₄ ) in water according to temperature.

The present invention relates to an apparatus for producing sodium bicarbonate (bacteria, NaHCO ₃ ) from industrial by-products containing sodium sulfate. Industrial by-products containing sodium sulfate (hereinafter also referred to as 'industrial by-products') may be solid or liquid industrial by-products. The industrial by-products are, but are not limited to, for example, waste desulfurization agent generated after using sodium bicarbonate as a desulfurization agent in a desulfurization process for removing sulfur oxides (SOx) in exhaust gas, sulfuric acid neutralization generated after neutralizing sulfuric acid Waste liquid etc. are mentioned.

For example, sodium bicarbonate used as a desulfurization agent reacts with SO ₂ in exhaust gas as shown in the following Reaction Formula [A] to convert NaHCO ₃ into Na ₂ SO ₄ . Accordingly, most of the components of the waste desulfurization agent (spent sodium bicarbonate) are Na ₂ SO ₄ , and major impurities include K, Ca, Fe, and the like. Components of the waste desulfurization agent were analyzed by XRF (X-Ray Fluorescence) and are shown in Table 1 below. The waste desulfurization agent may include, for example, components as shown in Table 1 below in the component contents of Table 1, but is not limited thereto. The content of sodium sulfate in the waste desulfurization agent depends on the amount of sodium bicarbonate (NaHCO ₃ ) used in the desulfurization process. Although not limited thereto, the content of sodium sulfate in the waste desulfurization agent may be approximately 70% to 100% by weight. .

2NaHCO ₃ + SO ₂ → Na ₂ SO ₄ + 2CO ₂ + H ₂ O [A]

No. ingredient Content (Unit:% by weight) One C 1.95 2 Na ₂ O 43.6 3 SO ₃ 36.4 4 Cl 7.47 5 _K2O 2.35 6 CaO 2.08 7 Fe ₂ O ₃ 4.81 8 impurities balance

In the production apparatus according to the present invention, calcium sulfate or calcium sulfate and calcium carbonate are produced in the process of removing impurities from industrial by-products containing sodium sulfate using the difference in solubility of each component, and finally sodium bicarbonate is obtained. In addition, the production apparatus of the present invention combines the effect of reducing CO ₂ by using CO ₂ . Hereinafter, an apparatus for producing sodium bicarbonate from an industrial by-product containing sodium sulfate according to the present invention will be described with reference to the drawings. 1 is a diagram schematically showing a manufacturing apparatus 100 and processes in the manufacturing apparatus according to the present invention. 2 is a view showing the manufacturing apparatus according to the present invention in more detail. As shown in FIG. 1, the manufacturing apparatus of the present invention includes a dissolving unit 10, a first solid precipitate generating unit 20, an optional second solid precipitate generating unit 20 ', and a sodium bicarbonate generating unit ( 30) included. In addition, as shown in more detail in FIG. 2, the first solid precipitate generating unit 20 in the manufacturing apparatus 100 includes a first solid precipitate generating tank 21 and a filter 22, an optional second solid precipitate The generation unit 20' includes a second solid precipitate generation tank 21' and a filter 22', and the sodium bicarbonate generation unit 30 includes a sodium bicarbonate generation tank 31 and a filter 32.

Apparatus 100 for producing sodium bicarbonate from industrial by-products containing sodium sulfate according to an embodiment of the present invention includes a dissolving unit 10, a first solid precipitate generating unit 20, and an optional second solid precipitate generating unit. (20 '), and a sodium hydrogen carbonate generating unit 30, wherein the treatment of sodium hydrogen carbonate from industrial by-products containing sodium sulfate in the manufacturing apparatus includes the dissolving unit 10, the first solid precipitate generating unit 20 , Optional second solid precipitate generating unit 20 ', and may include only the first cycle sequentially processed in the sodium bicarbonate generating unit 30.

In addition, the apparatus 100 for producing sodium bicarbonate from industrial by-products containing sodium sulfate according to another embodiment of the present invention includes a dissolving unit 10, a first solid precipitate generating unit 20, an optional second solid precipitate It includes a generating unit 20 ', and a sodium hydrogen carbonate generating unit 30, and the treatment of sodium bicarbonate from industrial by-products containing sodium sulfate in the manufacturing apparatus includes the dissolving unit 10, the first solid precipitate generating unit ( 20), the optional second solid precipitate generating section 20', and the first cycle sequentially processed in the sodium bicarbonate generating section 30; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit 30 of the first circulation is recycled to the dissolving unit 10, the dissolving unit 10, the first solid precipitate generating unit ( 20), an optional second solid precipitate generating unit 20', and a second cycle sequentially processed in the sodium bicarbonate generating unit 30.

In the present application, 'first circulation' refers to the introduction of sodium sulfate-containing industrial by-products into the dissolving unit 10 for the first time in the manufacturing apparatus of the present application, the dissolving unit 10, the first solid precipitate generating unit 20, and the optional second Refers to a cycle that first passes through the solid precipitate generating unit 20 'and the sodium bicarbonate generating unit 30, and 'second circulation' refers to hydrogen carbonate in the sodium bicarbonate generating unit 30 in the first cycle. The filtrate remaining after sodium recovery is recycled to the dissolving unit 10, and the dissolving unit 10, the first solid precipitate generating unit 20, the optional second solid precipitate generating unit 20 ', and the sodium bicarbonate generating unit Refers to a cycle that is processed by going through (30) again. As will be described later, the filtrate remaining after recovering sodium bicarbonate in the sodium bicarbonate generating unit 30 of the second circulation is recycled back to the dissolving unit 10 (eg, the third circulation, the fourth circulation, etc.) It may be repeated, and herein it is also referred to as 'after the second cycle' or 'above the second cycle'.

Reactions in the dissolution section and the production section in the first and second cycles of the manufacturing apparatus are as follows.

1st cycle: (Use of water in melting unit 10)

Melting part 10: Na ₂ SO ₄ → 2Na ⁺ + SO ₄ ^2- ----(1)

1st solid precipitate generating unit 20: 2Na ⁺ + SO ₄ ^2- + 2Ca(OH) ₂ → 2Na ⁺ + CaSO _4(s) ↓ + Ca ²⁺ + 4OH ^- ----(2)

Optional second solid phase precipitate generating section 20': 2Na ⁺ + Ca ²⁺ + 4OH ^- + CO ₂ → 2Na ⁺ + CaCO _3(s) ↓ + H ₂ O + 2OH ^- --- (2')

Sodium bicarbonate generation unit (30): 2Na ⁺ + 2OH ^- + 2CO ₂ → 2NaHCO _{3 (s)} ↓ --- (3)

After the second circulation (the filtrate (saturated sodium bicarbonate solution) of the sodium bicarbonate generating unit 30 is recycled to the dissolving unit 10, equilibrium)

Melting part 10: Na ₂ SO ₄ + Na ⁺ + HCO ₃ ^- → 3Na ⁺ + SO ₄ ^2- + HCO ₃ ^- ----(4)

The first solid phase precipitate generating unit 20: 3Na ⁺ + SO ₄ ^2- + HCO ₃ ^- + 2Ca(OH) ₂ → 3Na ⁺ + CaSO _4(s) + CaCO _3(s) + 3OH ^- + H ₂ O - ---(5)

(After the second cycle, it proceeds as in reaction formula (5) in the first solid precipitate generating unit 20, or the following reaction formula in the first solid precipitate generating unit 20 and the second solid precipitate generating unit 20' It proceeds as in (5') and (5").

The first solid phase precipitate generation unit 20: 3Na ⁺ + SO ₄ ^2- + HCO ₃ ^- + Ca(OH) ₂ → 3Na ⁺ + SO4 ^2- + CaCO _3(s) + OH ^- + H ₂ O --- (5')

Second solid precipitate generating unit (20'): 3Na ⁺ + SO ₄ ^2- + OH ^- + Ca(OH) ₂ → 3Na ⁺ + CaSO _4(s) + 3OH ^- ---(5"))

Sodium bicarbonate generating unit 30: 3Na ⁺ + 3OH ^- + 3CO ₂ → 3NaHCO _3(s) ----(6)

Hereinafter, the dissolving unit 10, the first solid precipitate generating unit 20 (including the first solid precipitate generating tank 21 and the filter 22), the optional second solid precipitate generating unit 20' (the second 2 manufacturing apparatus 100 including a solid precipitate generating tank 21' and a filter 22'), and a sodium bicarbonate generating unit 30 (including a sodium bicarbonate generating tank 31 and a filter 32) ) And the dissolving unit 10, the first solid precipitate generating unit 20, the optional second solid precipitate generating unit 20 ', and Treatment of sodium hydrogen carbonate from industrial by-products containing sodium sulfate in the process in the sodium hydrogen carbonate production section 30 describes the process.

(In the case where only the first cycle proceeds, or in the case of the second cycle or more, the process in the first cycle)

In the dissolution part 10 of the first circulation, the industrial by-product containing sodium sulfate is dissolved in water to prepare an aqueous solution of sodium sulfate. The industrial by-product contains sodium sulfate (Na ₂ SO ₄ ), and therefore, the sodium sulfate aqueous solution dissolved in water contains sodium ions and sulfate ions as shown in the reaction formula (1) above.

The amount of industrial by-products dissolved in water in the dissolving unit 10 is an amount in which sodium sulfate in industrial by-products is dissolved in water at 100 g/L to 400 g/L. That is, in the sodium sulfate aqueous solution, an amount of industrial by-products corresponding to 100 g to 400 g of sodium sulfate dissolved in 1 L of water is dissolved in water. The amount of sodium sulfate among industrial by-products can be found by XRF (X-Ray Fluorescence), IC (Ion Chromatography), etc. These methods are generally known methods for analyzing the components of chemical substances. , which will not be described in detail here. Industrial by-products include, but are not limited to, as described above, for example, waste desulfurization agent generated after using sodium bicarbonate as a desulfurization agent in a desulfurization process for removing sulfur oxides (SOx) from exhaust gas, and/or sulfuric acid. and sulfuric acid neutralization waste liquid generated after neutralization. Hereinafter, the description of the industrial by-products described above is equally applied to the contents of the industrial by-products of the present application.

Fresh water or tap water may be used as the water.

Unlike other salts, it is known that the solubility of Na ₂ SO ₄ increases as the temperature rises in a certain range, but decreases at a temperature of 40° C. or higher while maintaining a certain level. 3 shows a graph of solubility of sodium sulfate (Na ₂ SO ₄ ) in water according to temperature. Considering the solubility of sodium sulfate according to the temperature in the sodium sulfate solubility graph of FIG. 3, the industrial by-products are dissolved in water in the dissolution unit 10 of the manufacturing apparatus at a temperature of 10 ° C to 50 ° C, preferably 25 ° C to 45 ° C. Dissolution is preferred. When the temperature exceeds 50 °C, there is a problem in that only energy is excessively input without inducing solubility improvement, and there is a problem in that the dissolution rate and amount of CO ₂ are reduced due to the high temperature when CO ₂ is supplied in the subsequent step. At a temperature of less than 10 °C, the solubility of sodium sulfate (Na ₂ SO ₄ ) in industrial by-products is low, and sodium sulfate may not be dissolved or it may take a long time to dissolve.

Therefore, considering the solubility of Na ₂ SO ₄ and the temperature of 10 °C to 50 °C, preferably 25 °C to 45 °C, Na ₂ SO ₄ in industrial by-products is It is preferable to dissolve industrial by-products in water in an amount dissolved in 100 to 400 g (100 to 400 g/L) per 1 L of water. If it is less than 100 g/L, the production of NaHCO ₃ is low, and the process cycle must be repeatedly operated several times in the manufacturing apparatus of the present invention to produce NaHCO ₃ , so excessive operating energy may be consumed. If it exceeds 400 g/L, the solubility of Na ₂ SO ₄ is exceeded, and Na ₂ SO ₄ is undissolved, and the undissolved Na ₂ SO ₄ is removed in the filtration process, and the utilization rate of Na ₂ SO ₄ may be lowered.

On the other hand, in the case of a solution-phase industrial by-product, the sodium sulfate aqueous solution in the dissolving unit 10 may be adjusted so that the concentration of Na ₂ SO ₄ in the solution-phase industrial by-product is 100 to 400 g/L.

In the first solid precipitate generating unit 20, calcium sulfate is generated by reacting sulfate ions in the sodium sulfate aqueous solution prepared in the dissolving unit 10 with calcium ions provided by a calcium source. The reaction in the first solid precipitate generating unit 20 is as shown in the above reaction formula (2). As shown in FIG. 2, the first solid precipitate generating unit 20 includes a first solid precipitate generating tank 21 and a filter 22 for filtering and recovering the generated calcium sulfate solids to generate the first solid precipitate. It can be included at the rear end of the jaw 21.

Specifically, sodium ions (Na ⁺ ) and sulfate ions (SO ₄ ^2- ) generated by dissolving industrial by-products containing sodium sulfate in water in the sodium sulfate aqueous solution in the dissolving unit 10 exist. When a calcium source is supplied to the sodium sulfate aqueous solution in the first solid precipitate generating unit 20, Ca ²⁺ supplied by the calcium source reacts with SO ₄ ^2- to form CaSO ₄ . The calcium source is not limited thereto, but for example, at least one selected from the group consisting of Ca-containing waste, Ca(OH) ₂ and CaO may be used. However, in consideration of the reaction rate and subsequent CO ₂ dissolution process, it is preferable to use at least one selected from the group consisting of Ca(OH) ₂ and CaO as the calcium source (calcium source). Hereinafter, the description of the calcium source is equally applied to the content of the calcium source of the present application.

The addition amount of the calcium source is determined according to the concentration of SO ₄ ^2- present in the aqueous solution of sodium sulfate in the dissolving unit 10, which is proportional to the amount of Na ₂ SO ₄ dissolved in water in the dissolving unit 10. The calcium source has a molar concentration of Ca ²⁺ that is 0.9 to 1.1 times greater than the molar concentration of SO ₄ ^2- (ie, the molar concentration of Na ₂ SO ₄ dissolved in water) (ie, SO ₄ ^2- or Na When the concentration of ₂ SO ₄ is 1 M, 0.9 to 1.1 mol of calcium source (ie, the molar concentration of Ca ²⁺ ) is added so that the same applies below). If the added amount of the calcium source is less than 0.9 times the molarity of Ca ²⁺ molarity, SO ₄ ^2- is excessively remaining, and if it exceeds 1.1 times the molarity, the second solid precipitate generation unit described below ( 20') is required.

A calcium source is supplied to an aqueous solution of sodium sulfate at 25° C. to 45° C. to produce calcium sulfate. When the temperature is less than 25° C. or more than 45° C., the solubility of sodium sulfate is lowered and sodium sulfate may precipitate, which is not preferable.

Due to the low solubility of CaSO ₄ , CaSO ₄ is formed as a solid precipitate, which is removed and recovered as a solid content by filtration, and unreacted Ca ²⁺ and Na ⁺ remain as main components in the filtrate. Specifically, calcium sulfate may be filtered and recovered by the filter 22 at the rear of the first solid precipitate generating tank 21 shown in FIG. 2 .

When CaSO ₄ solid content is removed, heavy metals and particulate matter contained in industrial by-products are co-precipitated or removed by filtration. The removed particulate matter can be used as a cement additive or the like.

The second solid precipitate generating unit 20 'may optionally be included in the manufacturing apparatus 100 of the present invention as needed.

Ca ²⁺ may remain in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit 20 due to the solubility of CaSO ₄ , and CO ₂ may be present in the filtrate in the sodium bicarbonate generating unit 30 When added, residual Ca ²⁺ can precipitate as CaCO ₃ and affect the purity of the final product, NaHCO ₃ . Therefore, in order to precipitate and remove Ca ²⁺ in the filtrate as calcium carbonate solids, a second solid precipitate generating unit 20 ′ may be additionally included as needed.

When the second solid precipitate generating unit 20' is included, the reaction in the second solid precipitate generating unit 20' is as shown in the reaction formula (2').

In the second solid precipitate generating unit 20', CO ₂ is added to the residual filtrate after calcium sulfate recovery in the first solid precipitate generating unit 20' to precipitate and remove Ca ²⁺ as calcium carbonate solid content. . In the second solid precipitate generating unit 20', specifically, in the filtrate in the second solid precipitate generating tank 21', CO ₂ is added to the molar concentration, which is the molar solubility of calcium sulfate in the filtrate (ie, the molar concentration in the saturated solution). It dissolves at a molar concentration of 0.9 to 1.1 times that of If CO ₂ is _less than 0.9 times the molarity, it may not be desirable to improve the purity of NaHCO ₃ as Ca remains and is precipitated during NaHCO ₃ production. This is undesirable because the possibility of re-dissolution due to the lowered pH increases and CO ₂ that is lost without being used increases.

The second solid precipitate generating unit 20' may not operate when the concentration of Ca ²⁺ remaining in the filtrate is lower than the solubility of CaCO ₃ . That is, when the concentration of Ca ²⁺ remaining in the filtrate is greater than the solubility of CaCO ₃ , the second solid precipitate generating unit 20 ′ may be additionally provided to the removal device 100 . The second solid precipitate generating unit 20' may further improve the purity of the finally produced sodium bicarbonate by precipitating and removing Ca ²⁺ remaining in the filtrate in the form of CaCO ₃ .

The supply of CO ₂ to the filtrate in the second solid precipitate generating unit 20' and the production of calcium carbonate are performed at 25°C to 45°C. When the temperature is lower than 25°C or higher than 45°C, the solubility of Na ₂ SO ₄ is lowered and Na ₂ SO ₄ may precipitate, which is not preferable.

In the sodium bicarbonate generating unit 30, the filtrate remaining after filtration of calcium sulfate in the filter 22 of the first solid precipitate generating unit 20 (or the second solid precipitate generating unit 20 ') is included In this case, sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate after calcium carbonate is recovered in the second solid precipitate generating unit 20'. The reaction in the sodium hydrogen carbonate generating unit 30 is as shown in the above Reaction Formula (3). As shown in FIG. 2, the sodium bicarbonate producing unit 30 includes a sodium bicarbonate producing tank 31 and a filter 32 for filtering and recovering the generated sodium bicarbonate solids in the sodium bicarbonate producing tank 31 ) can be included at the end of

In the sodium bicarbonate generating tank 31 of the sodium bicarbonate generating unit 30, CO ₂ is added so that the molar concentration of CO ₂ is 1.0 to 2.2 times the molar concentration of sodium sulfate in the sodium sulfate aqueous solution of the dissolving unit 10. do. If the molar concentration of CO ₂ is less than 1.0 times, NaHCO ₃ is not formed as much as the solubility of NaHCO ₃ , so the production of NaHCO ₃ is lowered. In addition, in this case, as will be described later, when the filtrate obtained in the sodium bicarbonate generating unit 30 is recycled to the dissolving unit 10, Na ⁺ is not removed in the form of NaHCO ₃ , so Na is accumulated there may be a problem with When CO ₂ exceeds 2.2 times the molar concentration, it is not preferable in that CO ₂ loss occurs as an excess amount of CO ₂ is introduced.

The addition of CO ₂ to the filtrate and the generation of sodium bicarbonate in the sodium bicarbonate generating unit 30, specifically, the sodium bicarbonate producing tank 31, are performed at 25°C to 45°C. When the temperature is lower than 25°C or higher than 45°C, the solubility of Na ₂ SO ₄ is lowered and Na ₂ SO ₄ may precipitate, which is not preferable.

(after the second cycle)

Furthermore, additionally, in the production apparatus 100 of the present invention, the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit 30 may be recycled (after the second circulation) to the dissolving unit 10 there is.

In the case of the second circulation, the filtrate remaining after recovering sodium bicarbonate in the sodium bicarbonate generating unit 30 of the first cycle is introduced into the dissolving unit 10, and the filtrate is introduced as a sodium bicarbonate saturated solution. this is dissolved In this way, sodium bicarbonate, calcium sulfate and calcium carbonate are additionally recovered by recycling the filtrate in which sodium bicarbonate is dissolved to the dissolving unit 10 and operating the manufacturing apparatus 100.

The filtrate (sodium hydrogen carbonate saturated solution) from which sodium bicarbonate is removed from the sodium bicarbonate generating unit 30 is supplied to the dissolution unit 10 after the second circulation, and industrial by-products containing sodium sulfate are dissolved in the filtrate to obtain carbonic acid. An aqueous solution of sodium sulfate saturated with sodium hydrogen is obtained. Industrial by-products containing sodium sulfate are applied in the same manner as described in the dissolution section 10 of the first cycle.

The reaction in the dissolving unit 10 after the second circulation is as shown in the above reaction equation (4). In the dissolving unit 10 after the second circulation, industrial by-products are added to the filtrate (filtrate from which sodium bicarbonate is removed from the sodium bicarbonate generating unit 30 of the first cycle, sodium bicarbonate saturated solution), and the content of sodium sulfate in the filtrate is reduced. By dissolving to 100 g/L to 400 g/L, an aqueous solution of sodium sulfate saturated with sodium bicarbonate is obtained.

If the sodium sulfate content is less than 100 g/L, the production of NaHCO ₃ is low and excessive operating energy may be consumed because NaHCO ₃ is produced only when the process cycle is repeatedly operated several times in the manufacturing apparatus of the present invention. If it exceeds 400 g/L, the solubility of Na ₂ SO ₄ is exceeded, and Na ₂ SO ₄ is undissolved, and the undissolved Na ₂ SO ₄ is removed in the filtration process, and the utilization rate of Na ₂ SO ₄ may be lowered.

On the other hand, in the case of a solution-type industrial by-product, the aqueous solution of sodium sulfate in which sodium bicarbonate is saturated in the dissolving unit 10 is dissolved in the aqueous solution by using the solution-type industrial by-product and/or water (eg, fresh water or tap water). The concentration of Na ₂ SO ₄ may be adjusted to be 100 to 400 g/L.

It is preferable to dissolve the industrial by-products in the filtrate at 10 ° C to 50 ° C, preferably at 25 ° C to 45 ° C in the dissolution unit 10 after the second circulation. When the temperature exceeds 50 °C, there is a problem in that only energy is excessively input without inducing solubility improvement, and there is a problem in that the dissolution rate and amount of CO ₂ are reduced due to the high temperature when CO ₂ is supplied in the subsequent step. At a temperature of less than 10 °C, the solubility of sodium sulfate (Na ₂ SO ₄ ) in industrial by-products is low, and sodium sulfate may not be dissolved or it may take a long time to dissolve.

As shown in the above Reaction Formula (4), the aqueous solution of sodium sulfate saturated with sodium bicarbonate in the dissolving unit 10 after the second circulation contains 3Na ⁺ , SO ₄ ^2- and HCO ₃ ^- .

The production and recovery of calcium sulfate and calcium carbonate in the solid precipitate production unit after the second cycle may be performed sequentially in a single step or in two steps.

When performed in a single step, Ca ²⁺ is supplied by a calcium source to the sodium sulfate aqueous solution saturated with sodium bicarbonate in the first solid precipitate generating unit 20, specifically, the first solid precipitate generating tank 21, Each of sulfate ion (SO ₄ ^2- ) and bicarbonate ion (HCO ₃ ^- ) in sodium sulfate aqueous solution saturated with sodium hydrogen carbonate It reacts with Ca ²⁺ to form calcium sulfate and calcium carbonate, and is recovered in the filter 22 by a method such as filtration. In this case, after the second cycle, the second solid precipitate generating unit 20' is unnecessary.

When carried out in a single step, the reaction in the first solid precipitate generating unit 20 after the second circulation is as shown in Scheme (5) above.

The calcium source may include at least one selected from the group consisting of Ca ²⁺ -containing waste, calcium oxide and calcium hydroxide, preferably at least one selected from the group consisting of calcium oxide and calcium hydroxide. At this time, impurities such as heavy metals and particulate matter contained in industrial by-products may be filtered and removed together.

The amount of the calcium source added to the sodium bicarbonate-saturated aqueous solution of sodium sulfate is such that the molar concentration of Ca ²⁺ is 0.9 relative to the sum of the molar concentrations of Na ₂ SO ₄ and the molar concentrations of NaHCO ₃ in the aqueous sodium sulfate solution saturated with sodium bicarbonate. to 1.1 times the molar concentration. If the amount of Ca ²⁺ is less than 0.9 times the molar concentration, SO ₄ ^2- and HCO ₃ ^- are not completely removed, and if it exceeds 1.1 times the molar concentration, the undissolved calcium source is removed together with calcium sulfate and calcium carbonate precipitates. This is undesirable because the drug cost increases accordingly.

In the first solid precipitate generating unit 20 after the second circulation, addition of a calcium source and thus production of calcium sulfate and calcium carbonate are performed at 25°C to 45°C. When the temperature is lower than 25°C or higher than 45°C, the solubility of Na ₂ SO ₄ is lowered and Na ₂ SO ₄ may precipitate, which is not preferable.

On the other hand, as described above, the production and recovery of calcium sulfate and calcium carbonate after the second circulation may be performed sequentially in two steps, in which case, calcium carbonate and calcium sulfate are generated in the first solid precipitate generating unit 20 And in the second solid precipitate generating unit 20 ', respectively, they are generated and recovered sequentially.

In this case, in the first solid precipitate generating unit 20, specifically, in the first solid precipitate producing tank 21, a calcium source is added to an aqueous solution of sodium sulfate saturated with sodium bicarbonate prepared in the dissolving unit 10, and the sodium bicarbonate is saturated. By dissolving a small amount so that the molar concentration of Ca ²⁺ is 0.9 to 1.1 times the molar concentration of NaHCO ₃ in the sodium sulfate aqueous solution, only calcium carbonate precipitates with lower solubility are produced, and calcium carbonate is recovered in the filter 22 do. When the molar concentration of Ca ²⁺ is less than 0.9 times, HCO ₃ ^- in the form of calcium carbonate cannot be removed and remains, which is preferable in that the purity of calcium sulfate is lowered when calcium sulfate is recovered in the second solid precipitate generating tank 21' If it does not, and exceeds 1.1 times, it is not preferable in that calcium carbonate and calcium sulfate are produced at the same time and the purity of calcium carbonate is lowered. The reaction at this time is as shown in the above reaction formula (5').

When the calcium carbonate precipitate is formed, impurities such as heavy metals and particulate matter contained in the waste desulfurization agent may be filtered and removed together. The generation and recovery of calcium carbonate in the first solid precipitate generating unit 20 is performed at 25 °C to 45 °C. When the temperature is lower than 25°C or higher than 45°C, the solubility of Na ₂ SO ₄ is lowered and Na ₂ SO ₄ may precipitate, which is not preferable.

Then, in the second solid precipitate generating tank 21, specifically, in the second solid precipitate generating tank 21', after recovering calcium carbonate in the first solid precipitate generating unit 20, the calcium supply source is added to the remaining filtrate. Calcium sulfate precipitate is produced by dissolving sodium hydrogen so that the molar concentration of Ca ²⁺ is 0.9 to 1.1 times the molar concentration of Na ₂ SO ₄ in a saturated aqueous solution of sodium sulfate, and calcium sulfate is formed in the filter 22'. This is recovered by filtration or the like.

If the molar concentration of Ca ²⁺ is less than 0.9 times, it is undesirable in that sulfate ions are not completely removed, and if it exceeds 1.1 times, unreacted calcium ions are recovered as calcium carbonate in the sodium bicarbonate production tank 31, thereby reducing carbonic acid. This is not preferable because the purity of sodium hydrogen is lowered. The reaction at this time is as shown in the above reaction formula (5”).

The generation and recovery of the calcium sulfate precipitate in the second solid precipitate generating unit 20' is performed at 25 °C to 45 °C. When the temperature is lower than 25°C or higher than 45°C, the solubility of Na ₂ SO ₄ is lowered and Na ₂ SO ₄ may precipitate, which is not preferable.

The process in the sodium bicarbonate generating unit 30 after the second cycle is the same as the process in the sodium bicarbonate generating unit 30 in the first cycle. The reaction in the sodium bicarbonate generating unit 30 after the second circulation is as shown in the above reaction formula (6).

Sodium bicarbonate is formed by the addition of CO ₂ in the sodium bicarbonate generating unit 30 after the second cycle, specifically, in the sodium bicarbonate generating tank 31, which is recovered by filtration in the filter 32 and the remaining The filtrate to be recycled is recycled back to the dissolving unit 10 (specifically, the dissolving unit 10, the first solid precipitate generating unit 20 and the sodium bicarbonate generating unit 30 are repeated, or the dissolving unit 10, the second 1 solid precipitate generating unit 20, the second solid precipitate generating unit 20 'and sodium bicarbonate generating unit 30 may be repeated).

In the sodium bicarbonate generating unit 30, specifically, in the sodium bicarbonate producing tank 31, the filtrate (after the second circulation, when the production and recovery of calcium sulfate and calcium carbonate are performed in a single step in the solid precipitate generating unit) , The filtrate after calcium carbonate and calcium sulfate are recovered in the first solid precipitate generating unit 20; After the second cycle, the production and recovery of calcium sulfate and calcium carbonate in the solid precipitate generating unit are sequentially performed in two steps. In this case, _CO 2 is dissolved at a molar concentration of 1.0 to 2.2 times the sum of the molar concentrations of Na ₂ SO ₄ and NaHCO ₃ in the filtrate after calcium sulfate is recovered in the second solid precipitate generating unit 20). When CO ₂ is dissolved at a molar concentration less than 1.0 times, NaHCO 3 is not formed as much as the solubility of NaHCO ₃ , which is undesirable in that the production of NaHCO ₃ is lowered, and when _{CO 2 exceeds} 2.2 times the molar concentration, excess CO It is not preferable in that CO ₂ is lost as ₂ is added.

The addition of CO ₂ and the formation of sodium bicarbonate in the sodium bicarbonate generating unit 30 after the second cycle are performed at 25°C to 45°C. If the temperature is less than 25 °C, sufficient solubility of Na ₂ SO ₄ cannot be secured as the temperature of the filtrate decreases, and if it exceeds 45 °C, the solubility of NaHCO ₃ increases and the recovery rate of NaHCO ₃ decreases. ₂ SO ₄ It is not preferable because it may cause a problem in which the solubility is lowered.

As described above, the filtrate remaining after recovering sodium bicarbonate in the sodium bicarbonate generating unit 30 of the second circulation is recycled back to the dissolving unit 10 (eg, the third circulation, the fourth circulation, etc.) This may be referred to as 'after the second cycle' or 'second cycle abnormality'. The process 'after the second cycle' or 'above the second cycle' is the same as the process of the 'second cycle', and therefore, the 'second cycle' is also referred to as 'after the second cycle'.

Each circulation step of the manufacturing apparatus of the present invention described above, and each process in the dissolution section and the production section has been generally described. According to the configuration and recirculation of the manufacturing apparatus of the present invention described above, the manufacturing apparatus of the present invention is configured as in the following 1 to 6, and each process may be performed. The information described herein is equally applicable to all of the embodiments 1 to 6 below.

In the first embodiment, as an apparatus for producing sodium hydrogen carbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generation unit and a sodium hydrogen carbonate generation unit,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; and

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit.

In the second embodiment, as an apparatus for producing sodium hydrogen carbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generation unit, and a sodium hydrogen carbonate generation unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, it is sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit. Including a second cycle that becomes,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium sulfate in the first solid precipitate generating unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is transferred to the dissolving unit. recycled,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, sulfate ions and bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate react with calcium ions provided by a calcium source to produce and recover calcium sulfate and calcium carbonate;

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate and calcium carbonate in the first solid precipitate generating unit.

In the third embodiment, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and sodium bicarbonate generating unit,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit;

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after recovering the calcium carbonate in the second solid precipitate generating unit.

In the fourth embodiment, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and sodium bicarbonate generating unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, the dissolving unit, the first solid precipitate generating unit, and the second solid precipitate generating unit and hydrogen carbonate Including a second circulation sequentially processed in the sodium generating unit,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the sodium bicarbonate generation unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium sulfate in the first solid precipitate generation unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolution unit. become,

In the second cycle,

In the dissolving part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after recovering sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare an aqueous solution of sodium sulfate saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, calcium carbonate is produced and recovered by reacting bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate and calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the filtrate remaining after the recovery of calcium carbonate in the first solid precipitate generating unit and calcium ions provided by a calcium source,

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate in the second solid precipitate generating unit.

In the fifth embodiment, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and sodium bicarbonate generating unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, it is sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit. Including a second cycle that becomes,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit;

In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium carbonate in the second solid precipitate generating unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolving unit. become,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, calcium sulfate and calcium carbonate are generated and recovered by reacting calcium ions provided by a calcium supply source with sulfate ions and bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate;

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate and calcium carbonate in the first solid precipitate generating unit.

In the sixth embodiment, as an apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit and sodium hydrogen carbonate generating unit,

The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit and sodium bicarbonate It includes a second cycle that is sequentially processed in the generating unit,

In the first cycle,

In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared;

In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit;

In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the removal of calcium carbonate in the second solid precipitate producing unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolving unit. become,

In the second cycle,

In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate;

In the first solid precipitate generating unit, calcium carbonate is produced and recovered by reacting bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate and calcium ions provided by a calcium source;

In the second solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the filtrate remaining after the recovery of calcium carbonate in the first solid precipitate generating unit and calcium ions provided by a calcium source,

In the sodium bicarbonate generating unit, a production device is provided in which sodium bicarbonate is generated and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the second solid precipitate generating unit.

In the manufacturing apparatus according to the second and third to sixth embodiments, the filtrate remaining after recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the second cycle may be recycled back to the dissolving unit, and the number of times of recirculation is not particularly limited, and may be appropriately repeated, for example, by those skilled in the art in consideration of treatment of industrial by-products and/or recovery of sodium bicarbonate, calcium sulfate, and/or calcium carbonate.

Calcium sulfate, calcium carbonate and/or sodium bicarbonate are efficiently recovered with high purity by the production apparatus 100 of the present invention as described above.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible without departing from the technical spirit of the present invention described in the claims. It will be obvious to those skilled in the art.

Hereinafter, the present invention will be described in more detail through examples. However, the present invention is not limited to the following examples. An embodiment will be described with reference to FIG. 2 .

Example 1

A sodium sulfate aqueous solution was prepared by dissolving the waste desulfurization agent having the composition shown in Table 1 in fresh water at 30° C. to 40° C. in the dissolving unit 10. At this time, the waste desulfurization agent was dissolved in water so that the amount of sodium sulfate dissolved in 1 L of water was 400 g (400 g/L) in the sodium sulfate aqueous solution.

Thereafter, 208 g of Ca(OH) ₂ was added to an aqueous solution of sodium sulfate at 40° C. in the first solid precipitate production tank 21 and mixed. Accordingly, a precipitate of CaSO ₄ was formed, which was filtered through a filter 22 to recover a filtrate and 380 g of CaSO ₄ solids.

Then, as 248g (126.3L @ STP) of CO ₂ was dissolved in the filtrate at 40° C. in the sodium bicarbonate production tank 31, a precipitate of NaHCO ₃ was formed, which was filtered and recovered in the filter 32. did According to the above process, 346 g of NaHCO ₃ was recovered.

Example 2

(1st cycle)

A sodium sulfate aqueous solution was prepared by dissolving the waste desulfurization agent having the composition shown in Table 1 in fresh water at 30° C. to 40° C. in the dissolving unit 10. At this time, the waste desulfurization agent was dissolved in water so that the amount of sodium sulfate dissolved in 1 L of water was 400 g in the sodium sulfate aqueous solution.

Thereafter, 157 g of CaO was added to the sodium sulfate aqueous solution at 40° C. in the first solid precipitate generating tank 21 and mixed. Accordingly, a precipitate of CaSO ₄ was formed, which was filtered through a filter 22 to recover the filtrate (1) and 380 g of CaSO ₄ solids.

Thereafter, 248g of CO ₂ (126.3L @ STP) was dissolved in the filtrate (1) at 40° C. in the sodium bicarbonate generating tank (31), and thus a precipitate of NaHCO ₃ was formed, which was filtered through the filter (32). 346 g of NaHCO ₃ precipitate was recovered by filtration. The remaining filtrate (2) was recycled to the dissolving section (10).

(2nd cycle)

The waste desulfurization agent having the composition shown in Table 1 was dissolved in 1 L of the filtrate (2) at 40° C. in the dissolving unit 10 so that the amount of sodium sulfate was 400 g (400 g/L), thereby obtaining an aqueous solution of sodium sulfate saturated with sodium bicarbonate. .

Thereafter, 320.7 g of Ca(OH) ₂ was dissolved in an aqueous solution of sodium sulfate saturated with sodium hydrogen carbonate at 40° C. in the first solid precipitate generating tank 21, whereby CaSO ₄ and CaCO ₃ precipitates were formed, which The mixture was filtered through a filter (22) to obtain 532 g of a precipitate in which CaSO ₄ and CaCO ₃ were mixed and a residual filtrate (3).

Thereafter, 248g of CO ₂ (126.3L @ STP) was dissolved in the filtrate (3) at 40° C. in the sodium bicarbonate generating tank (31), and thus a precipitate of NaHCO ₃ was formed, which was removed from the filter (32). It was recovered by filtration. According to the above process, 346 g of NaHCO ₃ was recovered.

Example 3

A sodium sulfate aqueous solution was prepared by dissolving the waste desulfurization agent having the composition shown in Table 1 in fresh water at 30° C. to 40° C. in the dissolving unit 10. At this time, the waste desulfurization agent was dissolved in water so that the amount of sodium sulfate dissolved in 1 L of water was 400 g in the sodium sulfate aqueous solution.

Thereafter, in the first solid precipitate production tank 21, 157 g of CaO was added to the sodium sulfate aqueous solution at 40°C and mixed. Accordingly, a precipitate of CaSO ₄ was formed, which was filtered through a filter 22 to recover the filtrate (1) and 380 g of CaSO ₄ solids.

Thereafter, as 0.85 g (0.43L @ STP) of CO ₂ was dissolved in the filtrate (1) in the second solid precipitate generating tank 21', CaCO ₃ precipitate was formed, which was filtered in the filter 22' 1.9 g of CaCO ₃ and residual filtrate (2) were obtained.

Thereafter, as 248 g (126.3L @ STP) of CO ₂ was dissolved in the filtrate (2) in the sodium bicarbonate generating tank 31, a precipitate of NaHCO ₃ was formed, which was filtered and recovered in the filter 32. did According to the above process, 346 g of NaHCO ₃ was recovered.

Example 4

(1st cycle)

A sodium sulfate aqueous solution was prepared by dissolving the waste desulfurization agent having the composition shown in Table 1 in fresh water at 30° C. to 40° C. in the dissolving unit 10. At this time, the waste desulfurization agent was dissolved in water so that the amount of sodium sulfate dissolved in 1 L of water was 400 g in the sodium sulfate aqueous solution.

Thereafter, 208 g of Ca(OH) ₂ was added to an aqueous solution of sodium sulfate at 40° C. in the first solid precipitate production tank 21 and mixed. Accordingly, a precipitate of CaSO ₄ was formed, which was filtered through a filter 22 to obtain 380 g of solid CaSO ₄ and a residual filtrate (1).

Thereafter, as 248g of CO ₂ (126.3L @ STP) was dissolved in the filtrate (1) at 40° C. in the sodium bicarbonate generating tank 31, a precipitate of NaHCO ₃ was formed, which was filtered in the filter 32. The recovered and remaining filtrate (2) was recycled to the dissolution unit (10). According to the above process, 346 g of NaHCO ₃ was recovered.

(2nd cycle)

In the dissolving unit 10, the waste desulfurization agent having the composition of Table 1 is dissolved in 1 L of the filtrate (2) at 40° C. so that the amount of sodium sulfate is 400 g (i.e., 400 g/L) to obtain an aqueous solution of sodium sulfate saturated with sodium bicarbonate. got it

Thereafter, 112 g of Ca(OH) ₂ was dissolved in an aqueous solution of sodium sulfate saturated with sodium hydrogen carbonate at 40° C. in the first solid precipitate generating tank 21, thereby forming a CaCO ₃ precipitate. The CaCO ₃ precipitate was filtered through a filter (22) to recover 151 g of CaCO ₃ to obtain a filtrate (3).

Thereafter, as 208 g of Ca(OH) ₂ was dissolved in the filtrate 3 at 40° C. in the second solid precipitate generating tank 21′, a precipitate of CaSO ₄ was formed, which was filtered in the filter 22′. 380 g of CaSO ₄ was obtained and a filtrate (4) was obtained.

Thereafter, 248g of CO ₂ (126.2L @ STP) was dissolved in the filtrate (4) at 40° C. in the sodium bicarbonate generating tank 31, and thus a precipitate of NaHCO ₃ was formed. NaHCO ₃ was recovered by filtration through a filter (32). According to the above process, 346 g of NaHCO ₃ was recovered.

Example 5

(1st cycle)

A sodium sulfate aqueous solution was prepared by dissolving the waste desulfurization agent having the composition shown in Table 1 in fresh water at 30° C. to 40° C. in the dissolving unit 10. At this time, the waste desulfurization agent was dissolved in water so that the amount of sodium sulfate dissolved in 1 L of water was 400 g in the sodium sulfate aqueous solution.

Thereafter, 157 g of CaO was dissolved in the sodium sulfate aqueous solution at 40° C. in the first solid precipitate generating tank 21, thereby forming a precipitate of CaSO ₄ , which was filtered through a filter 22 to obtain a solid content of 380 g of CaSO ₄ . and a residual filtrate (1) was obtained.

Thereafter, as 0.85 g (0.43L @ STP) of CO ₂ was dissolved in the filtrate (1) at 40° C. in the second solid precipitate generating tank (21′), a precipitate of CaCO ₃ was formed, which was filtered (22 ') to obtain 1.9 g of CaCO ₃ and residual filtrate (2).

Thereafter, 248 g (126.3 L @ STP) of CO ₂ was dissolved in the filtrate (2) again at 40° C. in the sodium bicarbonate generating tank 31, and thus a precipitate of NaHCO ₃ was formed. Thereafter, 346 g of NaHCO ₃ and a residual filtrate (3) were obtained by filtering through a solid precipitate filter (32) of NaHCO ₃ . The remaining filtrate (3) was recycled to the dissolving section (10).

(2nd cycle)

In the dissolving unit 10, the waste desulfurization agent having the composition of Table 1 is dissolved in 1 L of the filtrate (3) at 40° C. so that the amount of sodium sulfate is 400 g (i.e., 400 g/L) to obtain an aqueous solution of sodium sulfate saturated with sodium bicarbonate. got it

Thereafter, 320.7 g of Ca(OH) ₂ was dissolved in an aqueous solution of sodium sulfate saturated with sodium hydrogen carbonate at 40° C. in the first solid precipitate generating tank 21, whereby CaSO ₄ and CaCO ₃ precipitates were formed. CaSO ₄ and CaCO ₃ precipitates were filtered through a filter 22 to obtain 531 g of a solid content in which CaSO ₄ and CaCO ₃ were mixed and a residual filtrate (4).

Thereafter, 248g of CO ₂ (126.2L @ STP) was dissolved in the filtrate (4) at 40° C. in the sodium bicarbonate generating tank 31, and thus a precipitate of NaHCO ₃ was formed. NaHCO ₃ was recovered by filtration through a filter (32). According to the above process, 346 g of NaHCO ₃ was recovered.

Example 6

(1st cycle)

A sodium sulfate aqueous solution was prepared by dissolving the waste desulfurization agent having the composition shown in Table 1 in fresh water at 30° C. to 40° C. in the dissolving unit 10. At this time, the waste desulfurization agent was dissolved in water so that the amount of sodium sulfate dissolved in 1 L of water was 400 g in the sodium sulfate aqueous solution.

Thereafter, 157 g of CaO was dissolved in the sodium sulfate aqueous solution at 40° C. in the first solid-phase precipitate generating tank 21, thereby forming a precipitate of CaSO ₄ . The precipitate of CaSO ₄ was filtered through filter 22 to recover residual filtrate (1) and 380 g of CaSO ₄ solids.

Thereafter, as 0.85 g (0.43L @ STP) of CO ₂ was dissolved in the filtrate (1) at 40° C. in the second solid precipitate generating tank (21′), a precipitate of CaCO ₃ was formed, which was filtered (22 ') to obtain 1.9 g of CaCO ₃ and residual filtrate (2).

Thereafter, 248 g (126.3 L @ STP) of CO ₂ was dissolved in the filtrate (2) again at 40° C. in the sodium bicarbonate generating tank 31, and thus a precipitate of NaHCO ₃ was formed. The solid precipitate of NaHCO ₃ was filtered through a filter (32) to obtain 346 g of NaHCO ₃ and residual filtrate (3), which was recycled to the dissolving section (10).

(2nd cycle)

In the dissolving unit 10, the waste desulfurization agent having the composition of Table 1 is dissolved in 1 L of the filtrate (3) at 40° C. so that the amount of sodium sulfate is 400 g (i.e., 400 g/L) to obtain an aqueous solution of sodium sulfate saturated with sodium bicarbonate. got it

Thereafter, 112 g of Ca(OH) ₂ was dissolved in an aqueous solution of sodium sulfate saturated with sodium hydrogen carbonate at 40° C. in the first solid precipitate generating tank 21, thereby forming a CaCO ₃ precipitate. The CaCO ₃ precipitate was filtered through a filter (22) to recover 151 g of CaCO ₃ to obtain a filtrate (4).

Thereafter, as 208 g of Ca(OH) ₂ was dissolved in the filtrate 4 at 40° C. in the second solid precipitate generating tank 21′, a precipitate of CaSO ₄ was formed, which was filtered in the filter 22′. Thus, 380 g of CaSO ₄ and residual filtrate (5) were obtained.

Thereafter, 248g of CO ₂ (126.2L @ STP) was dissolved in the filtrate (5) at 40° C. in a sodium bicarbonate generating tank (31), whereby a precipitate of NaHCO ₃ was formed. NaHCO ₃ was recovered by filtration through a filter (32). According to the above process, 346 g of NaHCO ₃ was recovered.

In the apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate (hereinafter also referred to as 'manufacturing apparatus') of the present invention, industrial by-products containing sodium sulfate are stably treated, and sodium bicarbonate (NaHCO ₃ ) as well as calcium sulphate (CaSO ₄ , gypsum) and calcium carbonate (CaCO ₃ ) are recovered.

Claims (13)

An apparatus for producing sodium hydrogen carbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generation unit and a sodium hydrogen carbonate generation unit, In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared; In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; and In the sodium bicarbonate generating unit, sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate in the first solid precipitate generating unit. An apparatus for producing sodium hydrogen carbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generation unit, and a sodium hydrogen carbonate generation unit, The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, it is sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit. Including a second cycle that becomes, In the first cycle, In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared; In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; In the sodium bicarbonate generating unit, after recovering calcium sulfate in the first solid precipitate generating unit, carbon dioxide is dissolved in the remaining filtrate to generate and recover sodium bicarbonate, and the filtrate remaining after recovering sodium bicarbonate is dissolved in the dissolved carbon dioxide. recycled into wealth, In the second cycle, In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate; In the first solid precipitate generating unit, sulfate ions and bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate react with calcium ions provided by a calcium source to produce and recover calcium sulfate and calcium carbonate; In the sodium bicarbonate generating unit, sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate and calcium carbonate in the first solid precipitate generating unit. An apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit, and a sodium hydrogen carbonate generating unit, In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared; In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit; In the sodium bicarbonate generating unit, after the recovery of calcium carbonate in the second solid precipitate generating unit, carbon dioxide is dissolved in the remaining filtrate to produce and recover sodium bicarbonate. An apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit, and a sodium hydrogen carbonate generating unit, The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, the dissolving unit, the first solid precipitate generating unit, and the second solid precipitate generating unit and hydrogen carbonate Including a second circulation sequentially processed in the sodium generating unit, In the first cycle, In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared; In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; In the sodium bicarbonate generation unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium sulfate in the first solid precipitate generation unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolution unit. become, In the second cycle, In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare an aqueous solution of sodium sulfate saturated with sodium hydrogen carbonate; In the first solid precipitate generating unit, calcium carbonate is produced and recovered by reacting bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate and calcium ions provided by a calcium source; In the second solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the filtrate remaining after the recovery of calcium carbonate in the first solid precipitate generating unit and calcium ions provided by a calcium source, In the sodium bicarbonate generating unit, sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate in the second solid precipitate generating unit. An apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit, and a sodium hydrogen carbonate generating unit, The treatment in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, it is sequentially processed in the dissolving unit, the first solid precipitate generating unit, and the sodium bicarbonate generating unit. Including a second cycle that becomes, In the first cycle, In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared; In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit; In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the recovery of calcium carbonate in the second solid precipitate generating unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolving unit. become, In the second cycle, In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate; In the first solid precipitate generating unit, calcium sulfate and calcium carbonate are generated and recovered by reacting calcium ions provided by a calcium supply source with sulfate ions and bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate; In the sodium bicarbonate generating unit, sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate and calcium carbonate in the first solid precipitate generating unit. An apparatus for producing sodium bicarbonate from industrial by-products containing sodium sulfate, including a dissolution unit, a first solid precipitate generating unit, a second solid precipitate generating unit, and a sodium hydrogen carbonate generating unit, The processing in the manufacturing apparatus includes a first cycle in which industrial by-products containing sodium sulfate are sequentially processed in the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit, and the sodium bicarbonate generating unit; And after the filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the first circulation is recycled to the dissolving unit, the dissolving unit, the first solid precipitate generating unit, the second solid precipitate generating unit and sodium bicarbonate It includes a second cycle that is sequentially processed in the generating unit, In the first cycle, In the dissolving unit, an aqueous solution of sodium sulfate in which industrial by-products containing sodium sulfate are dissolved in water is prepared; In the first solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the sodium sulfate aqueous solution with calcium ions provided by a calcium source; In the second solid precipitate generating unit, calcium carbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after recovering calcium sulfate in the first solid precipitate generating unit; In the sodium bicarbonate generating unit, carbon dioxide is dissolved in the filtrate remaining after the removal of calcium carbonate in the second solid precipitate producing unit to generate and recover sodium bicarbonate, and the filtrate remaining after the recovery of sodium bicarbonate is recycled to the dissolving unit. become, In the second cycle, In the dissolution part, an industrial by-product containing sodium sulfate is dissolved in the filtrate remaining after the recovery of sodium hydrogen carbonate in the sodium hydrogen carbonate generating part of the first cycle to prepare a sodium sulfate aqueous solution saturated with sodium hydrogen carbonate; In the first solid precipitate generating unit, calcium carbonate is produced and recovered by reacting bicarbonate ions in an aqueous solution of sodium sulfate saturated with sodium bicarbonate and calcium ions provided by a calcium source; In the second solid precipitate generating unit, calcium sulfate is generated and recovered by reacting sulfate ions in the filtrate remaining after the recovery of calcium carbonate in the first solid precipitate generating unit and calcium ions provided by a calcium source, In the sodium bicarbonate generating unit, sodium bicarbonate is produced and recovered by dissolving carbon dioxide in the filtrate remaining after the recovery of calcium sulfate in the second solid precipitate generating unit. According to any one of claims 2 and 4 to 6, The filtrate remaining after the recovery of sodium bicarbonate in the sodium bicarbonate generating unit of the second circulation is recycled back to the dissolving unit. According to any one of claims 1 to 6, The calcium source is at least one selected from the group consisting of Ca ²⁺ -containing waste, calcium oxide and calcium hydroxide, manufacturing apparatus. According to any one of claims 1 to 6, Industrial by-products containing sodium sulfate are dissolved in water or filtrate at a temperature of 10 ° C to 50 ° C in the dissolution unit. According to any one of claims 1 to 6, Production of calcium sulfate, calcium sulfate and calcium carbonate or calcium carbonate in the first solid precipitate generating unit is carried out at a temperature of 25 ℃ to 45 ℃, manufacturing apparatus. According to any one of claims 3 to 6, Production of calcium carbonate or calcium sulfate in the second solid precipitate generating unit is carried out at a temperature of 25 ℃ to 45 ℃, manufacturing apparatus. According to any one of claims 1 to 6, Production of sodium hydrogen carbonate in the sodium hydrogen carbonate generating unit is carried out at a temperature of 25 ℃ to 45 ℃, manufacturing apparatus. According to any one of claims 1 to 6, The industrial by-product containing sodium sulfate is a waste desulfurization agent or sulfuric acid neutralization waste liquid, manufacturing apparatus.

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