CN107779603A - A kind of method that ceruse is prepared in the scrap lead from oxidation - Google Patents

Abstract

A kind of method that ceruse is prepared in scrap lead from oxidation, belong to the recycling field of the scrap lead containing oxidation.Comprise the following steps：(1) oxidation scrap lead is converted into lead sulfate crude product with sulfuric acid composite solution.(2) the X Y conjugate solutions of lead sulfate crude product in (1) are dissolved, dissolves the lead sulfate in crude product, it is filtered to obtain lead sulfate filtrate and insoluble impurity.(3) carbonaceous material is added in the lead sulfate filtrate obtained to (2), is isolated to ceruse.What the inventive method can be widely applied in the waste lead acid battery lead plaster in various sources, lead-acid battery production to produce waste material and smelting process contain scrap lead, has the advantages that lead recovery height, mother liquid recycling.

Description

A method for preparing lead carbonate from lead oxide waste

technical field

The invention relates to recovery of lead oxide waste and a preparation method of lead carbonate, belonging to the field of recovery of lead oxide-containing waste.

Background technique

In recent years, with China's industrialization and urbanization process, my country's lead industry has developed rapidly, gradually occupying an important position in the global lead industry chain. In 2003, my country overtook the United States to become the world's largest producer of refined lead. In contrast, due to environmental pollution in the production process of refined lead in Western countries, the output of refined lead has declined year by year. In 2004, my country surpassed the United States to become the world's largest lead consumer. According to the data released by the International Lead and Zinc Research Group, in 2011, the global output of refined lead was 10.372 million tons, and the consumption was 10.216 million tons; the output of refined lead in my country was 4.648 million tons, and the consumption was 4.632 million tons. And consumption accounts for about 45% of the global market. The main consumption areas of lead are batteries, cable sheaths, lead oxide and lead materials. Due to the advantages of low price, high safety and mature technology, lead-acid batteries are widely used. The storage battery industry is the main field of lead consumption, accounting for about 80% of the total consumption.

A large amount of lead production and lead consumption is accompanied by lead recycling. The lead oxide waste produced from lead production to lead consumption includes: waste battery dismantling lead paste, waste grid, flue ash, waste lead paste during battery preparation, Lithopone leaching slag, lead anode slime, copper converter soot slag, beneficiation tailings, zinc plant waste slag, etc. For the above-mentioned various lead oxide wastes, pyrometallurgy recycling technology is generally adopted in the world. However, there is a secondary pollution problem in pyrometallurgy. Scholars at home and abroad are actively researching wet-process lead regeneration technology in response to the secondary pollution problem of pyrometallurgy.

Wet treatment fundamentally eliminates the secondary pollution problems of lead dust and SO2 pollution, and is an environmentally friendly treatment method for lead _oxide waste. The final product of wet recovery lead can be lead compound or metallic lead. Basically adopt leaching agent leaching, process flow of leach solution purification, crystallization or precipitation to produce lead salt or electrolysis to produce metallic lead. Lead oxide powder is obtained by transforming the waste lead paste of waste lead-acid batteries, among which Huazhong University of Science and Technology published patent CN201210121636.2 uses raw materials such as sodium carbonate and waste lead paste to undergo desulfurization reaction, and then uses the desulfurization lead paste to react with citric acid solution and dry to obtain lead citrate , Roast lead citrate, and finally get superfine lead oxide powder. Although this invention conforms to the characteristics of clean production, it cannot prepare high-purity lead oxide powder because there is no impurity removal link in the whole process, and the additives added in the lead-acid battery preparation process cannot be removed. This method is relatively strict in the selection of raw materials, and is only suitable for the recovery of waste lead paste, but not for other lead oxide wastes (lithopone leaching slag, lead anode slime, copper converter soot slag, mineral processing tailings, zinc plant waste slag, etc.). The lead paste desulfurization method of waste lead-acid batteries, wherein the patent CN102925698B of Wuhan University of Science and Technology uses ammonia water or a solution containing amino substances to dissolve lead paste, but a single ammonia water or a solution containing amino substances has a relatively low dissolving ability for lead sulfate in lead plaster , so not only waste of ammonia water or solution containing amino substances, but also lower production efficiency. Secondly, this method has strict requirements on the source of raw materials, because ammonia water has a relatively strong complexing ability for metal oxides such as Zn and Cu, and this method cannot effectively remove impurities when the raw materials contain the above-mentioned metal oxides.

The lead paste desulfurization method of waste lead-acid batteries, in which South China Normal University published patent CN103633394 A uses carbonate to desulfurize the lead paste of waste lead-acid batteries. Since the whole system is a solid-liquid reaction, the solid-phase lead sulfate and carbonate solution After the reaction, the resulting lead carbonate is a precipitate that is more insoluble than lead sulfate, so it is easy to form a precipitate that wraps lead carbonate on the outside and inside is the core of lead sulfate. The problem of lead sulfate residue leads to low desulfurization rate, and the purity of the product lead carbonate is not good. high.

A method for preparing a mixture of lead carbonate and silver carbonate from the filter residue obtained from producing lithopone. The disclosed patent CN102167393 A utilizes lead chloride and silver chloride in raw materials to react with sodium carbonate to generate lead carbonate, silver carbonate and sodium chloride. Perform coarse filtration to separate the elemental sulfur filter cake and microemulsion, and then perform fine filtration on the microemulsion to separate the mixture filter cake of lead carbonate and silver carbonate and sodium chloride filtrate. Since the method does not recover the Pb element and the Ag element separately, the resulting product is a mixture of lead carbonate and silver carbonate with low economic value. And other insoluble impurities in the product cannot be effectively removed only by simple coarse filtration and fine filtration.

_In the invention patent ( _CN105197988A ), an ammonia separation and purification method of lead _sulfate ( _{PbSO 4} ) is disclosed _{. 4} The aqueous solution is used as a solvent, and the separation and purification of PbSO ₄ is realized by adopting steps such as leaching and dissolving, impurity removal and purification, evaporation and crystallization, and solid-liquid separation. The main problem of this invention is to use lead sulfate to dissolve PbSO ₄ under the pressure of 30-100 atmospheres and 36mol/L of ultra-high pressure ammonia water, which far exceeds the operable conditions of 6-12mol/L of atmospheric pressure ammonia water. Concentrated ammonia water has great harm to the design of the reactor and the health of employees. It can be seen that there is difficulty in the dissolution of lead sulfate in a single ammonia solution.

For most of the current recovery of lead oxide waste to prepare lead carbonate, the sulfidation process of lead-containing waste and the subsequent lead sulfate desulfurization process are necessary reaction steps. From above prior art, the main problem that exists is as follows:

(1) Lead oxide is less efficient in the vulcanization process and is easily covered by lead sulfate with low solubility, making it difficult to vulcanize the core of the raw material.

(2) In the desulfurization process of lead sulfate, the sulfuration is not complete due to the insoluble lead sulfate and lead carbonate.

(3) There is no effective impurity removal link in the vulcanization and carbonization process, resulting in the prepared lead carbonate being mixed with various impurities in a large amount of original lead oxide waste. Therefore, in the process of wet recovery of lead oxide waste, it is urgent to invent a new type of lead oxide-containing waste to be directly recycled into high-purity lead carbonate, which has become an urgent problem to be solved in the current wet recovery of lead.

Contents of the invention

The present invention aims to overcome the technical defects in the prior art, aiming at the problems of high recycling cost of lead oxide waste, low economic value of by-products, low purity of produced products, etc., a method for preparing lead carbonate from lead oxide waste is proposed.

In order to achieve the above object, the technical scheme adopted by the present invention includes three steps of (1) vulcanization, (2) leaching and (3) carbonization. The method (1) promotes the conversion of lead oxide waste into lead sulfate through the vulcanization process, (2) dissolves the generated lead sulfate through a conjugated complexing agent to separate the lead sulfate solution from impurities, and (3) finally passes sulfuric acid The carbonization process of the lead solution can obtain high-purity lead carbonate, and the conjugated complexing agent can be recycled and reused.

The concrete steps of the technical solution adopted in the present invention comprise as follows:

(1) vulcanization: lead oxide waste is acidified with sulfuric acid composite solution A to obtain lead sulfate crude product; sulfuric acid composite solution A is a mixed solution of sulfuric acid and other inorganic acids or sulfuric acid and organic acids;

(2) Leaching: Dissolving and filtering the lead sulfate crude product acidified with sulfuric acid composite solution A with X-Y conjugate solution to obtain lead sulfate filtrate and insoluble impurities; X in the X-Y conjugate solution is one or more of organic amines or ammonia Kind, Y is ammonium salt;

(3) carbonization: the lead sulfate filtrate obtained in step (2) is contacted with carbonaceous substances to obtain lead carbonate and filtrate B, which are carbon dioxide, carbonate or organic substances that can decompose carbon dioxide.

In a kind of method step (1) for preparing lead carbonate from lead oxide waste according to the present invention, other inorganic acids are preferably selected from one or both of nitric acid, phosphoric acid, hydrochloric acid, and perchloric acid in the sulfuric acid composite solution A. species, the organic acid is preferably selected from formic acid, acetic acid, propionic acid, butyric acid, octanoic acid, adipic acid, oxalic acid, malonic acid, tartaric acid, citric acid, methanesulfonic acid, alpha aminocarboxylic acid, 1-fluoroacetic acid , one or both of sulfamic acid and cyclohexanoic acid.

Before carrying out step (1) of the present invention, lead oxide waste material can be converted into relatively higher content lead oxide waste material by pre-conversion treatment, such as removing Pb and PbO in the raw material by pre _- roasting in the raw material Components such as , to obtain roasted lead paste.

In a kind of method step (1) that prepares lead carbonate from lead oxide waste material according to the present invention, lead oxide waste material is added in reactor, adds sulfuric acid composite solution A in reactor, and temperature of reaction is controlled at 20- 120°C, stirring continuously for 0.1-5h, then performing solid-liquid separation to obtain crude lead sulfate and filtrate after acidification conversion.

Preferably, the reaction temperature is 20-100°C, more preferably 20-80°C. The acidification time shall be subject to the realization of complete vulcanization.

In a method step (2) for preparing lead carbonate from lead oxide waste according to the present invention, the crude lead sulfate after sulfidation needs to be added to the reactor, and a sufficient amount of X-Y conjugated solution is added to the reactor The X-Y conjugated solution described in this step, wherein X is preferably ammonia, ethylenediamine, propylenediamine, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, propylenediaminediacetic acid, diethanolamine, triethanolamine One or two; Y is preferably one or two of ammonium chloride, ammonium bisulfate, ammonium sulfate, ammonium nitrate, ammonium carbonate, ammonium bicarbonate, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate. In order to better realize the leaching effect of lead sulfate, the concentration of X in the conjugate solution is controlled to be 2-15mol/L, and the concentration of Y is controlled to be 0.2-5.0mol/L, and it is continuously stirred under the condition of 20-120°C. Generally, the stirring time is 1-120 minutes, and the specific stirring time can be based on the leaching effect of the actual material. The leached solution is subjected to solid-liquid separation to obtain lead-containing filtrate and insoluble impurities. Preferably, the concentration of X in the conjugated solution is 5-15 mol/L, and the concentration of Y is 0.5-5.0 mol/L. More preferably, the concentration of X is 5-13 mol/L, and the concentration of Y is 0.5-4.0 mol/L. The preferred reaction temperature is 20-100°C, more preferably 20-80°C.

In step (3) of a method for preparing lead carbonate from lead oxide waste according to the present invention, the lead-containing filtrate and carbonaceous substances are subjected to a contact reaction to obtain lead carbonate and filtrate B. The reacted solution is separated by centrifugation or filtration to obtain a lead carbonate solid and a conjugated solution containing desulfurization by-products. In this step, the filtrate B can be used in the leaching process of step (2) again by lowering the temperature to remove sulfate. The carbonaceous substance described in step (3) is selected from one or both of carbonates, carbon dioxide or other organic substances capable of decomposing carbon dioxide. After a large number of tests, the carbonate is one or both of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, and the substances that can decompose carbon dioxide are oxalic acid and acetic acid , one or both of formic acid, citric acid, tartaric acid, oxalic acid, malonic acid, and urea.

In this carbonization process, the temperature used for carbonization is 0-100°C, and the time used for carbonization is 0.1-5h. Preferably, the carbonization reaction temperature is 30-60°C, and the carbonization reaction time is 0.2-1h.

The lead carbonate prepared by the invention can be directly used as a product, or can be prepared into high-purity lead oxide by roasting, and the decomposed carbon dioxide can also be returned to step (3) for recycling.

Detailed ways

In order to better illustrate the principles and invention points of the present invention, the present invention will be further described below in conjunction with the embodiments.

The present invention firstly provides a method for preparing lead sulfate complex, comprising: a pre-transformation process of lead oxide waste; a catalytic conversion process of crude lead sulfate; and a complexing process of X-Y conjugate solution.

When the lead-containing waste contains other non-lead oxide components, a higher content of lead oxide waste can be obtained through the pre-conversion process of the lead-containing waste. Pre-transformation process: The raw material of the pre-transformation process is lead oxide-containing waste, the main source of which is dismantling lead paste from waste batteries, waste grids, flue ash, waste lead paste from the battery preparation process, lithopone leaching residue, and lead anodes Mud, copper converter soot slag, ore dressing tailings, zinc plant waste slag, etc. In this process, the lead-containing components Pb, PbO, PbO ₂ and PbSO ₄ in the raw materials are converted through high-temperature roasting, so that Pb and PbO ₂ in the components react to become PbO. The main components of the final roasted product are Pb and PbSO ₄ .

The specific reaction is as follows:

Pb+PbO ₂ =2PbO

2Pb+O ₂ =2PbO

2PbO ₂ =2PbO+O ₂

In the process of catalytic vulcanization, the PbO in the above-mentioned pre-converted lead oxide waste material containing PbO and PbSO4 is converted into lead _sulfate by reacting with sulfuric acid composite solution under the action of a catalyst.

For example, in an implementation process, the present invention reacts the mixed solution of pre-transformed lead oxide waste with sulfuric acid and acetic acid, so that the PbO in the pre-transformed lead oxide waste reacts with sulfuric acid to generate lead sulfate, wherein the sulfuric acid and acetic acid The concentrations are 3mol/L and 0.3mol/L respectively, the reaction temperature is 105°C, and the reaction time is 1.5h.

In step (1), H ₂ SO ₄ can be the waste liquid of the lead-acid battery, the new sulfuric acid liquid, or a mixture of the two. Acetic acid mainly plays a catalytic role, because the product H ₂ SO ₄ is insoluble, and lead acetate is soluble, so choosing acetic acid as a catalyst can speed up the reaction process.

The specific reaction is as follows:

PbO+2CH ₃ COOH=Pb(CH ₃ COO) ₂ +H ₂ O

Pb(CH ₃ COO) ₂ +H ₂ SO ₄ ＝PbSO ₄ +H ₂ O

The overall reaction equation is:

PbO+H ₂ SO ₄ ＝PbSO ₄ +H ₂ O

The reaction solution in the step (1) is filtered and separated to obtain lead sulfate and mother liquor containing sulfuric acid and acetic acid. The resulting lead sulfate crude product is set aside.

Then, the consumed sulfuric acid is added to the mother liquor containing sulfuric acid and acetic acid, and the mother liquor added with sulfuric acid is returned to the step (1) for recycling.

During the leaching process, since lead sulfate is difficult to dissolve in common solvents or solutions, although high-concentration ammonia water can dissolve lead sulfate, the actual solubility is limited. The present invention finds that lead sulfate has good solubility in X-Y conjugate solution, thereby achieving the purpose of leaching lead sulfate in lead-containing waste under normal pressure and separating it from insoluble impurities.

The present invention finds in research process, although many metallic impurities such as Ca, Fe, Mn, Cr, Sn, Sb, Bi, Al and Mg are difficult to dissolve in above-mentioned conjugated complexing agent, but some Cu, Zn, Cd and Ag The four metal element compounds will also be leached to some extent. For lead oxide waste from dismantling lead paste of waste batteries, waste grids, and waste lead paste in the battery preparation process, the above-mentioned leaching and carbonization processes can be completed in one step. For lead oxide waste from lithopone leaching slag, lead anode slime, copper converter soot slag, ore dressing tailings, zinc plant waste slag, etc., the present invention preferably needs to add PbSO to the lead _sulfate filtrate of leaching Recrystallization process, that is, by Add PbSO4 crystals to the lead _sulfate filtrate to induce the precipitation of lead sulfate in the solution, separate out the lead sulfate crystals, and then separate from the metal impurities to obtain pure lead sulfate, which is dissolved in the XY conjugated solution again, A relatively pure lead sulfate solution is obtained.

The step ( ₂ ) leaching process comprising the addition of PbSO for recrystallization includes the following steps:

(1) lead sulfate crude product is added X-Y conjugated solution and dissolves, thereby the lead sulfate of solid is converted into the complex compound of lead sulfate. In the conjugate dissolution process of the present invention, we think that the following dissolution process may have taken place, and its reaction formula is expressed as follows:

PbSO ₄ +X+H ₂ O=PbHX(OH)SO ₄ (1)

PbXH(OH)SO ₄ ＝PbSO ₄ +X+H ₂ O (2)

Wherein the concentration of X in the conjugate solution is 2-15mol/L, the concentration of Y is 0.2-5.0mol/L, the reaction temperature is 20-120°C, and the reaction time is 1-120min.

(II) The reaction solution in the step (I) is filtered or centrifuged, and high-purity PbSO is added to the filtrate crystal, and the lead _sulfate complexed and dissolved in the solution is separated out. The crystallization temperature is 0-90°C, and the crystallization time is 1-10h. Preferably, the crystallization temperature is 45° C., and the crystallization time is 2 hours.

(III) The lead sulfate crystal crystallized in the step (II) is filtered or centrifuged, and then dissolved with the above-mentioned X-Y conjugate solution to obtain a lead sulfate solution free of Cu, Zn, Cd and Ag metal elements. Figure 1 shows that the method of the present invention further includes the step of preparing lead carbonate by desulfurization. The step includes reacting the prepared lead sulfate complex with carbonaceous substances, thereby achieving the purpose of preparing lead carbonate.

The invention adopts the compound solution A and the X-Y conjugate solution in the vulcanization process to realize the conversion of lead oxide-containing waste into high-concentration lead sulfate solution. The discovery and use of new conjugated complexing agents not only greatly improved the solubility of lead sulfate, but also provided a liquid phase reaction basis for the subsequent addition of carbonaceous substances to quickly and thoroughly carbonize the process. Compared with the reported desulfurization processes such as sodium carbonate, ammonium carbonate or sodium hydroxide, the present invention converts the original heterogeneous solid-liquid reaction system into a homogeneous liquid-liquid reaction system, making the desulfurization of the lead paste easier to carry out. It not only shortens the desulfurization time but also greatly increases the desulfurization rate. Experiments show that the lead sulfate conversion rate of the present invention reaches over 99.5%, and the carbonization desulfurization rate of lead also reaches 99.9%.

The present invention adopts X-Y conjugated solution + carbon-containing material circulation desulfurization technology, the price of desulfurizer is relatively low, easy to obtain, the reaction liquid after desulfurization can be recycled and reused, and the recovery of lead-containing waste is realized to the greatest extent from the perspective of atomic economy Process cleaning. The existing desulfurization process does not require large-scale equipment improvement, and can be directly automated after improvement, which facilitates the industrialization of the new process.

Hereinafter, the embodiments will be described in more detail with reference to Examples. The examples are only used to illustrate the present invention, not to limit the present invention.

Example 1

Take lead oxide waste from Zhejiang Chaowei Battery Factory. The lead oxide waste was put into a muffle furnace and roasted at 600°C for 0.5h. The roasted lead paste whose main component is lead oxide after roasting is obtained, which is mainly 95% lead oxide (PbO) according to chemical determination, and the remaining amount is 3% lead sulfate and 2% clay. After processing as follows, the specific steps are:

(1) Vulcanization process: Add 1.00kg of roasted lead oxide waste into a 10L vulcanization reactor, add 6L of a composite solution of 5.0mol/L sulfuric acid+1.0mol/L acetic acid into the reactor, and control the reaction temperature at 70°C. The stirring rate was 300r/min, and the solid-liquid separation was carried out after continuous stirring for 3.0h to obtain 1.33kg of crude lead sulfate after acidification conversion and the mother liquor of compound acid. The crude PbSO ₄ was analyzed, and the content of PbSO ₄ was 99.5%, and the remaining components were a solid mixture of a very small amount of insoluble impurities. After adding the consumed sulfuric acid, the composite acid mother liquor is recycled as the solution of the next vulcanization process, and the _PbSO4 crude product is transferred to the subsequent process for processing.

( ₂ ) Leaching process: the PbSO crude product obtained in (1) is added in the 20L complexation reactor, and the XY conjugated solution of 10L is added in the reactor, wherein X is ethylenediamine concentration in the conjugated solution and is 8.0mol /L, Y is the concentration of ammonium bisulfate is 2.0mol/L. Then, it was stirred continuously for 10 min under the condition of 30° C., and the stirring speed was 380 r/min. Solid-liquid separation is then carried out to obtain lead-containing filtrate and insoluble impurities. 10g of high-purity PbSO ₄ was added to the filtrate, so that the lead component in the filtrate was transformed into PbSO ₄ and crystallized. The crystallization temperature was 45° C. and the crystallization time was 2 hours. _The PbSO4 crystals were separated and dissolved again with the above XY conjugate solution to obtain the complex solution.

(3) Carbonization process: transfer the complex solution obtained in (2) into a closed carbonization reaction kettle, and control the reaction temperature to 30° C. and the stirring rate to 450 r/min. Add a sufficient amount of ammonium carbonate to the reaction kettle, and continue to stir until no more precipitation occurs. And the reaction mixture was filtered and separated to obtain the lead carbonate precipitate and the mixed solution of the conjugated system and ammonium sulfate.

Adopt the recovery method described in this embodiment, finally obtained 1.14kg lead carbonate product. Chemical titration calculates that its desulfurization rate is 99.97%, the lead recovery rate is 98.6%, and the prepared lead carbonate has a purity of 99.6%.

Example 2

The waste valve-regulated sealed lead-acid batteries with commercially available specifications of 12V and 7Ah were crushed and separated by conventional methods to obtain lead paste. The separated lead paste was put into a muffle furnace and baked at 600° C. for 1 h. A roasted lead paste whose main components are lead oxide and lead sulfate after roasting is obtained. The converted lead paste is analyzed by traditional chemical titration to obtain 40.2% of lead sulfate, 59.4% of lead oxide and 0.4% of other impurities.

Proceed as follows, the specific steps are:

(1) Vulcanization process: Add 1.00kg of pretreated converted lead paste into a 10L vulcanization reaction kettle, add 6L of a composite solution of 3.0mol/L sulfuric acid + 1.0mol/L acetic acid into the vulcanization reaction kettle, and control the reaction temperature at 80°C , the stirring speed is 300r/min, after continuous stirring for 3.0h, the solid-liquid separation is carried out, and the lead paste and filtrate after acidification conversion are obtained. The mixture that obtains after filtration separation reaction obtains _1.21kg PbSO Crude product and compound acid mother liquor. The crude PbSO ₄ was analyzed, and the content of PbSO ₄ was 99.6%, and the rest was a solid mixture of very small amount of insoluble impurities. After adding the consumed sulfuric acid, the composite acid mother liquor is recycled as the solution of the next vulcanization process, and the above _- mentioned PbSO4 crude product is transferred to the subsequent process for processing.

( ₂ ) Leaching process: the PbSO crude product obtained in (1) is added in the 20L complexation reactor, and the XY conjugated solution of 10L is added in the reactor, wherein X is ethylenediamine concentration in the conjugated solution and is 7.0mol /L, Y is the concentration of ammonium sulfate is 2.0mol/L. Then, it was stirred continuously for 10 min under the condition of 30° C., and the stirring speed was 380 r/min. Solid-liquid separation is then carried out to obtain lead-containing filtrate and insoluble impurities.

(3) Carbonization process: transfer the lead-containing filtrate obtained in (2) to a closed carbonization reactor, control the reaction temperature at 20°C and stir at a rate of 450r/min under the condition of continuous stirring, add a sufficient amount of Sodium carbonate, stirring continuously until no further precipitation occurs. And the reaction mixture was filtered and separated to obtain the lead carbonate precipitate and the mixed solution of the conjugated system and ammonium sulfate.

By adopting the recovery method described in this example, 1.06 kg of lead carbonate product was finally obtained, and the equivalent lead recovery rate was 99.5%. The desulfurization rate of the product is 99.96% and the purity of lead carbonate is 99.3% through chemical titration analysis.

Example 3

Take lead oxide waste from Zhejiang Huitong Power Supply Company. The lead oxide waste was put into a muffle furnace and roasted at 600°C for 0.5h. The calcined lead paste whose main components are lead oxide and lead sulfate after roasting is obtained, which is mainly 95% lead oxide (PbO) according to chemical determination, and the remainder is lead sulfate and clay.

The recovery concrete steps of this lead oxide waste material are:

(1) Vulcanization process: Add 1.00kg of roasted lead oxide waste into a 10L vulcanization reactor, add 6L of a composite solution of 5.0mol/L sulfuric acid+1.0mol/L acetic acid into the reactor, and control the reaction temperature at 70°C. The stirring rate was 300r/min, and the solid-liquid separation was carried out after continuous stirring for 3.0h to obtain 1.33kg of crude lead sulfate after acidification conversion and the mother liquor of compound acid. The crude PbSO ₄ was analyzed, and the content of PbSO ₄ was 99.6%, and the rest was a solid mixture of very small amount of insoluble impurities. After adding the consumed sulfuric acid, the composite acid mother liquor is recycled as the solution of the next vulcanization process, and the _PbSO4 crude product is transferred to the subsequent process for processing.

(2) Leaching process: put the PbSO4 crude product obtained in ( ₁ ) into a 20L complexation reactor, and add 10L of XY conjugated solution to the reactor, wherein X in the conjugated solution is ammonia and the concentration is 11.0mol/L , Y is that the concentration of ammonium sulfate is 2.0mol/L. Then, it was stirred continuously for 10 min under the condition of 30° C., and the stirring rate was 380 r/min. Solid-liquid separation is then carried out to obtain lead-containing filtrate and insoluble impurities. 10g of high-purity PbSO ₄ was added to the filtrate, so that the lead component in the filtrate was transformed into PbSO ₄ and crystallized. The crystallization temperature was 45° C. and the crystallization time was 2 hours. _The PbSO4 crystals were isolated and dissolved again with the above XY conjugate solution to give a leaded solution.

(3) Carbonization process: transfer the lead-containing solution obtained in (2) into a closed carbonization reaction kettle, and control the reaction temperature to 20° C. under the condition of a stirring rate of 450 r/min. Carbon dioxide gas was introduced into the reaction kettle until no more precipitation occurred. And the reaction mixture was filtered and separated to obtain the lead carbonate precipitate and the mixed solution of the conjugated system and ammonium sulfate.

Adopt the recovery method described in this embodiment, finally obtained 1.18kg lead carbonate product. The desulfurization rate is 99.95%-99.97%, the recovery rate is 99.2%, and the recovered lead carbonate has a purity of 99.2%-99.5%.

Example 4

The waste valve-regulated sealed lead-acid batteries with commercially available specifications of 12V and 7Ah were crushed and separated by conventional methods to obtain lead paste. The separated lead paste was put into a muffle furnace and baked at 600° C. for 1 h. A roasted lead paste whose main components are lead oxide and lead sulfate after roasting is obtained. The converted lead paste is analyzed by traditional chemical titration to obtain 40.2% of lead sulfate, 59.4% of lead oxide, and 0.4% of other impurities such as iron.

The specific steps of the lead waste are:

(1) Vulcanization process: Add 1.00kg of pretreated converted lead paste into a 10L vulcanization reaction kettle, add 6L of a compound solution of 2.5mol/L sulfuric acid + 0.5mol/L acetic acid into the vulcanization reaction kettle, and control the reaction temperature at 80°C , the stirring speed is 300r/min, after continuous stirring for 3.0h, the solid-liquid separation is carried out, and the lead paste and filtrate after acidification conversion are obtained. The mixture that obtains after filtration separation reaction obtains _1.21kg PbSO Crude product and compound acid mother liquor. The crude PbSO ₄ was analyzed, and the content of PbSO ₄ was 99.6%, and the rest was a solid mixture of very small amount of insoluble impurities. After adding the consumed sulfuric acid, the composite acid mother liquor is recycled as the solution of the next vulcanization process, and the above _- mentioned PbSO4 crude product is transferred to the subsequent process for processing.

(2) leaching process: the PbSO obtained in (1) _The crude product is added in the 20L complexation reactor, and the XY conjugated solution of 10L is added in the reactor, wherein X is the ammonia of 10.0mol/L in the conjugated solution, Y is 2.5mol/L ammonium sulfate. Then, it was stirred continuously for 10 min under the condition of 30° C., and the stirring speed was 380 r/min. Solid-liquid separation is then carried out to obtain lead-containing filtrate and insoluble impurities.

(3) Carbonization process: transfer the lead-containing filtrate obtained in (2) to a closed carbonization reactor, control the reaction temperature to be 20°C and the stirring rate is 450r/min under the condition of continuous stirring, and pass carbon dioxide into the reactor gas until no more precipitation occurs. And the reaction mixture was filtered and separated to obtain the lead carbonate precipitate and the mixed solution of the conjugated system and ammonium sulfate.

By adopting the recovery method described in this example, 1.06 kg of lead carbonate product was finally obtained, the desulfurization rate was 99.97%, the lead recovery rate was 99.1%, and the purity of the prepared lead carbonate was 99.4%-99.7%.

Claims (10)

1. a method for preparing lead carbonate from lead oxide waste, is characterized in that, may further comprise the steps: (1) vulcanization: lead oxide waste is acidified with sulfuric acid composite solution A to obtain lead sulfate crude product; sulfuric acid composite solution A is a mixed solution of sulfuric acid and other inorganic acids or sulfuric acid and organic acids; (2) Leaching: Dissolving and filtering the lead sulfate crude product acidified with sulfuric acid composite solution A with X-Y conjugate solution to obtain lead sulfate filtrate and insoluble impurities; X in the X-Y conjugate solution is one or more of organic amines or ammonia Kind, Y is ammonium salt; (3) carbonization: the lead sulfate filtrate obtained in step (2) is contacted with carbon-containing substances to obtain lead carbonate and filtrate B, and the carbon-containing substances are carbon dioxide, carbonate or organic substances that can decompose carbon dioxide. 2. according to a kind of method preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, in the sulfuric acid composite solution A described in step (1), other inorganic acids are selected from nitric acid, phosphoric acid, hydrochloric acid, high One or two of chloric acid, organic acid selected from formic acid, acetic acid, propionic acid, butyric acid, caprylic acid, adipic acid, oxalic acid, malonic acid, tartaric acid, citric acid, methanesulfonic acid, alpha amino One or both of carboxylic acid, 1-fluoroacetic acid, sulfamic acid and cyclohexanoic acid. 3. according to a kind of method preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, in step (1), lead oxide waste is added in reactor, adds sulfuric acid composite solution in reactor A, the reaction temperature is controlled at 20-120°C, the solid-liquid separation is carried out after continuous stirring for 0.1-5h, and the acidified and converted lead sulfate crude product and filtrate are obtained; the preferred reaction temperature is 20-100°C, more preferably 20-80°C. 4. according to a kind of method for preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, in step (2), the lead sulfate crude product after sulfidation needs to be added in reactor, in reactor Add a sufficient amount of X-Y conjugated solution; the X-Y conjugated solution described in this step, wherein X is ammonia, ethylenediamine, propylenediamine, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, propylenediaminediacetic acid, One or both of diethanolamine and triethanolamine; Y is ammonium chloride, ammonium bisulfate, ammonium sulfate, ammonium nitrate, ammonium carbonate, ammonium bicarbonate, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate one or two. 5. according to a kind of method preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, the concentration control of X in the conjugate solution is 2-15mol/L, and the concentration control of Y is 0.2-5.0mol /L, and continuously stirred under the condition of 20-120°C; the concentration of X in the conjugated solution is 5-15mol/L, and the concentration of Y is 0.5-5.0mol/L. More preferably, the concentration of X is 5-13 mol/L, and the concentration of Y is 0.5-4.0 mol/L; the preferred reaction temperature is 20-100°C. 6. according to a kind of method preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that carbonate is ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, salt of wormwood, potassium bicarbonate One or two of them, the organic substance capable of decomposing carbon dioxide is one or two of oxalic acid, acetic acid, formic acid, citric acid, tartaric acid, oxalic acid, malonic acid, and urea. 7. according to a kind of method for preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, in the carbonization process, the temperature used for carbonization is 0-100 ℃, and the time used is 0.1-5h, preferably The carbonization reaction temperature is 30-60°C, and the carbonization reaction time is 0.2-1h. 8. according to a kind of method for preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, step (2) also comprises to the lead sulfate filtrate of leaching adding PbSO ₄ recrystallization process, namely by adding to sulfuric acid Add PbSO4 crystals in the lead filtrate to induce the precipitation of lead sulfate in the solution, separate out the lead _sulfate crystals, and then separate from the metal impurities to obtain pure lead sulfate, which is dissolved in the XY conjugated solution again to obtain a relatively Pure lead sulfate solution. 9. according to a kind of method for preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that, described lead oxide waste is selected from: waste battery dismantling lead plaster, waste and old grid, flue ash, battery Waste lead paste, lithopone leaching slag, lead anode slime, copper converter soot slag, beneficiation tailings, zinc plant waste slag during the preparation process. 10. according to a kind of method for preparing lead carbonate from lead oxide waste according to claim 1, it is characterized in that gained lead carbonate is directly used as product, or is prepared into high-purity lead oxide by roasting, and the carbon dioxide that decomposes returns step simultaneously (3) Recycling.