WO2018072499A1 - Method for recovering basic copper chloride from copper-containing waste liquid in sulfuric acid system - Google Patents

Abstract

A method for recovering basic copper chloride from a copper-containing waste liquid in a sulfuric acid system. The method comprises the following steps: S1, adjusting the pH value of a copper-containing waste liquid in a sulfuric acid system, adding excess iron dust to the copper-containing waste liquid for a displacement reaction, carrying out liquid-solid separation after the reaction is completed, and collecting a first solid phase; S2, mixing white mud with the first solid phase, reacting, carrying out liquid-solid separation, and collecting a second solid phase; S3, adding ammonium chloride and water or a mother liquor obtained following basic copper chloride production into the treated second solid phase as processed in S2, adjusting the pH value, reacting, carrying out liquid-solid separation, and collecting a third liquid phase; S4, reacting the third liquid phase with hydrochloric acid, and carrying out liquid-solid separation, so as to obtain the basic copper chloride. The method takes full advantage of discarded raw materials, saves on costs and achieves the purpose of treating waste with waste. The various indicators of the produced basic copper chloride each meet national standards.

Description

Method for recovering basic copper chloride from copper-containing waste liquid of sulfuric acid system Technical field

The invention belongs to the field of industrial waste recycling, and particularly relates to a method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system.

Background technique

In the production process of the circuit board, the micro-etching process produces a micro-etching waste liquid, a process of electroplating processing, a copper sulfate waste liquid, and a browning process to produce a browning waste liquid. These waste liquids are all copper-containing waste liquids of sulfuric acid system, which have the characteristics of low copper content, high COD content and difficulty in recycling, and direct discharge will cause serious pollution to the environment. In the prior art, copper is recovered mainly by a metal replacement method, a neutralization precipitation method, or an electrodeposition method. However, the existing methods have their own problems. For example, the copper recovery rate of the metal replacement method is low, the purity of the obtained sponge copper is low, the composition of the waste liquid is complicated, and the treatment is difficult; the crystal form of the copper salt obtained by the neutralization precipitation method is not good, and the copper content is biased. Low, the subsequent treatment of waste liquid is difficult and costly; the electrodeposition method has high energy consumption.

Therefore, it is necessary to develop a method for efficiently treating and maximizing the recovery of copper in the copper-containing waste liquid of the sulfuric acid system.

Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to overcome the deficiencies of the prior art and to provide a method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system. The method can maximize the recovery of copper in the copper-containing waste liquid and convert it into a high value-added product such as basic copper chloride, and the subsequent wastewater treatment is simple, no three-waste discharge, and is in line with green production and comprehensive recycling of resources. in principle.

The above object of the present invention is achieved by the following technical solutions:

A method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system, comprising the following steps:

S1. Adjusting the pH of the copper-containing waste liquid in the sulfuric acid system to 2 to 2.5, adding excess iron scraps to the copper-containing waste liquid, performing a displacement reaction, and separating the solid and liquid after the reaction to obtain the first solid phase and the first Liquid phase, drying and pulverizing the first solid phase;

S2. mixing the white mud slurry with the first solid phase after S1 pulverization at a mass ratio of 2 to 4:1, reacting for 2 to 3 hours, and separating the solid and liquid to obtain a second solid phase and a second liquid phase;

S3. Adding 1 to 1.5 times of ammonium chloride solids and water or a mother liquor after producing basic copper chloride to the second solid phase after S2 treatment, adjusting with ammonia water and maintaining the pH value between 8 and 8.8 The reaction temperature is 45 to 55 ° C, the reaction time is 0.5 to 1 hour, and solid-liquid separation is performed to obtain a third solid phase and a third liquid phase;

S4. The third liquid phase is reacted with hydrochloric acid having a mass concentration of 8 to 10%, the temperature is controlled at 75 to 90 ° C, the pH is controlled at 4.5 to 5.0, the reaction time is 2 to 5 hours, and solid-liquid separation is performed to obtain basic copper chloride. .

By the method of S1, the copper is enriched as much as possible, and then the white mud is used to remove the oil and toxic and harmful heavy metals in the copper, and then the ammonia leaching and the basic copper chloride are synthesized, and the basic chlorination with high purity can be obtained. Copper, and wastewater from the process, can pass through a simple Fenton reaction system, which removes COD and heavy metals.

Preferably, in S1, the size of the iron filings is over 100 mesh.

Preferably, in S1, the size of the first solid phase after pulverization is over 100 mesh.

Preferably, in S1, the pH of the first liquid phase is adjusted to 3.0 to 3.5, and the hydrogen peroxide is added to carry out the Fenton reaction, and the residue after the reaction is smelted.

Preferably, in S2, the white mud is prepared by diluting and mixing the white mud with 2 to 4 times the mass of water.

Preferably, in S2, the pH of the second liquid phase is adjusted to 3.0 to 3.5, and the hydrogen peroxide is added to carry out the Fenton reaction, and the residue after the reaction is smelted.

Preferably, in S3, after the solid-liquid separation, the third solid phase is washed, and the washing water is mixed with the filtrate to form a third liquid phase.

Preferably, in S3, a mother liquor having a mass of 1 to 1.5 times of ammonium chloride and a mother liquor of basic copper chloride is added to the second solid phase after the S2 treatment to carry out a reaction. The mother liquor after the production of basic copper chloride contains a relatively high concentration of copper ions and ammonium chloride, which can promote the reaction and improve the efficiency.

Generally, in S3, the amount of the mother liquor after the clean water or the production of the basic copper chloride is equivalent to the mass of the second solid phase. Preferably, in S3, the obtained third solid phase is smelted.

In S4, the hydrochloric acid used may be commercially available ordinary hydrochloric acid, acid etching waste liquid or other waste hydrochloric acid. From the viewpoint of the composition of the raw materials, the purity of ordinary hydrochloric acid is the highest, the purity of the acid etching waste liquid is second, and the purity of the waste hydrochloric acid is the second. From the perspective of cost, ordinary hydrochloric acid is the most expensive, acid etching waste liquid also needs to be purchased at a cost, and waste hydrochloric acid is a seller who needs to pay a processing fee. Therefore, preferably, in S4, the hydrochloric acid is waste hydrochloric acid. Usually the source of waste hydrochloric acid is a chemical plant. Preferably, the spent hydrochloric acid is removed by filtration to remove solid impurities therein before use.

Preferably, in S4, the liquid phase obtained after solid-liquid separation is used as a mother liquid after the production of basic copper chloride as described in S3.

Preferably, in S4, the liquid phase obtained after solid-liquid separation is subjected to evaporation and concentration to recover ammonium chloride, which can be directly used for S3 as a raw material for the ammonia leaching step.

Preferably, in S1, the mass content of calcium carbonate in the white mud is 8-18%; the mass content of sodium carbonate is 1-3.5%.

Preferably, in the copper-containing waste liquid of the sulfuric acid system, the content of copper is 10 to 30 g/L.

Compared with the prior art, the present invention has the following beneficial effects:

The method of the invention can maximize the recovery of copper in the copper-containing waste liquid and convert it into a high value-added product such as basic copper chloride, and the subsequent wastewater treatment is simple, no three wastes are discharged, and the green production and resource comprehensive cycle are met. The principle of utilization. The degreasing treatment of sponge copper with white mud can not only be more effective, saves the process, but also cures harmful metals in the sponge copper, especially chromium, so that the harmful metals are not leached during the subsequent ammonia leaching process, so that It is easier to obtain a pure copper-ammonium complex solution during ammonia leaching, which improves the quality of the product. In the process of preparing basic copper chloride, it is possible to replace conventional acid etching waste liquid or other acid raw materials with waste hydrochloric acid, thereby saving cost and increasing profit.

detailed description

The invention is further illustrated in detail below with reference to the specific embodiments, but the examples are not intended to limit the invention in any way. In the examples, the percentages are all calculated as mass percentages. The reagents and devices used in the examples are all commercially available devices.

In the examples, the properties of the microetching waste liquid used are as shown in Table 1:

Table 1: Microetching waste liquid provided by an electronics factory

In the examples, the properties of the copper sulfate waste liquid used are as shown in Table 2:

Table 2: Copper sulphate waste liquid provided by an electronics factory

In the examples, the properties of the browning waste liquid used are as shown in Table 3:

Table 3: Browning waste liquid provided by an electronics factory

In the examples, the white mud used is supplied by a chemical plant containing 40 to 50% by mass of calcium carbonate and 5 to 10% by mass of sodium carbonate.

In the examples, the properties of the spent hydrochloric acid used are shown in Table 4:

Table 4: Waste hydrochloric acid provided by an electronics factory

Example 1

A method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system, comprising the following steps:

S1. 2000 mL of a microetching waste liquid containing 12.8 g/L of copper was adjusted to a pH of 2.5 with a 30 wt% sodium hydroxide solution, and 22.64 g of iron scraps pulverized to 100 mesh were added to the copper-containing waste liquid to carry out a displacement reaction. After reacting for 15 minutes, the solid phase is separated to obtain a first solid phase and a first liquid phase, and the first solid phase is dried and pulverized to 100 mesh to obtain about 38.8 g of sponge copper, and the copper content is 64%;

S2. Take 30g of white mud, add 60g of water, and stir well to make white mud;

77.6 g of white mud was added to the above 38.8 g of sponge copper, degreasing and solidifying the toxic and harmful metal, reacting for 2 hours, solid-liquid separation to obtain a second solid phase and a second liquid phase; the second liquid phase and the first liquid The mixture is treated by the Fenton method;

The second solid phase is rinsed with water and has a weight of about 71.78 g;

S3. In 71.78 g of the second solid phase after S2 treatment, 71.78 g of ammonium chloride solid and 71.78 g of water were added, adjusted with ammonia water and maintained at pH 8, heated to 45 ° C, and reacted for 1 hour to carry out solid-liquid reaction. After separation, the obtained third solid phase was rinsed and sent to a steel smelting plant, weighing about 39.38 g; the third solid phase washing water was mixed with the remaining liquid to form 232.8 mL of a third liquid phase containing copper 99.4 g/L.

S4. The waste hydrochloric acid is diluted with water to a concentration of 8 wt%, and the solid impurities are removed by filtration, and reacted with the third liquid phase, and an ammonium chloride solution prepared by dissolving 15 g of ammonium chloride in 100 mL of water is used as a reaction mother liquid, and the temperature is controlled at 75 ° C. The pH was controlled at 4.5, the reaction time was 2 hours, solid-liquid separation, and the solid was rinsed and centrifuged to obtain 38.9 g of light green basic copper chloride crystals.

Example 2

A method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system, comprising the following steps:

S1. 2000 mL of micro-etching waste liquid containing 16.20 g/L of copper was adjusted to pH 2.3 with a 30 wt% sodium hydroxide solution, and 32.6 g of iron scraps pulverized to 100 mesh were added to the copper-containing waste liquid to carry out a displacement reaction. After reacting for 15 minutes, the solid phase is separated to obtain a first solid phase and a first liquid phase, and the first solid phase is dried and pulverized to 100 mesh to obtain a sponge copper of about 53.62 g and a copper content of 60.8%;

S2. Take 60g of white mud, add 120g of water, and stir well to make white mud;

160.87g of white mud was added to the above 53.62g of sponge copper, degreasing and solidifying toxic and harmful metals, reacting for 2.5 hours, solid-liquid separation to obtain a second solid phase and a second liquid phase; the second liquid phase and the first liquid The mixture is treated by the Fenton method;

The second solid phase is rinsed with water and has a weight of about 104.56 g;

S3. To 71.78 g of the second solid phase after the S2 treatment, 156.84 g of ammonium chloride solid and 104.56 g of the basic copper chloride production mother liquid of Example 1 were added, adjusted with ammonia water and maintained at a pH of 8.5, and heated to At 50 ° C, after 1 hour of reaction, solid-liquid separation was carried out, and the obtained third solid phase was rinsed and sent to an iron and steel smelting plant, weighing about 71.38 g; the third solid phase washing water was mixed with the remaining liquid to form a third liquid phase of 312.0 mL. It contains 98.32g/L of copper.

S4. The waste hydrochloric acid is diluted with water to a concentration of 9 wt%, and the solid impurities are removed by filtration, and reacted with the third liquid phase, and 100 mL of the basic copper chloride mother liquid of Example 1 is used as a reaction mother liquid, and the temperature is controlled at 85 ° C, and the pH is controlled. 4.8, the reaction time was 3 hours, solid-liquid separation, the solid was rinsed, and centrifuged to obtain 51.40 g of light green basic copper chloride crystal.

Example 3

A method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system, comprising the following steps:

S1. The microetching waste liquid containing 23.45 g/L of copper is adjusted to a pH of 2.5 by using a 30 wt% sodium hydroxide solution, and 49.25 g of iron scraps pulverized to 100 mesh are added to the copper-containing waste liquid to carry out a displacement reaction. After reacting for 15 minutes, the solid phase is separated to obtain a first solid phase and a first liquid phase, and the first solid phase is dried and pulverized to 100 mesh to obtain a sponge copper of about 80.4 g and a copper content of 61.25%;

S2. Take 150g of white mud, add 300g of water, and stir well to make white mud;

321.6g white mud was added to the above 80.4g sponge copper to remove oil and solidify toxic and harmful metals, react for 3 hours, solid-liquid separation to obtain second solid phase and second liquid phase; second liquid phase and the first liquid The mixture is treated by the Fenton method;

The second solid phase is rinsed with water and has a weight of about 209.04 g;

S3. To the 209.04 g second solid phase after the S2 treatment, 261.3 g of ammonium chloride solid and 209.04 g of the basic copper chloride production mother liquid of Example 1 were added, adjusted with ammonia water and maintained at a pH of 8.8, and heated. After 55 hours of reaction to 55 ° C, the solid-liquid separation was carried out, and the obtained third solid phase was rinsed and sent to an iron and steel smelting plant, weighing about 142.71 g; the third solid phase washing water was mixed with the remaining liquid to form a third liquid phase of 455 mL. It contains 95.58g/L of copper.

S4. Diluting the waste hydrochloric acid with water to a concentration of 10% by weight, filtering to remove solid impurities, reacting with the third liquid phase, using 100 mL of basic copper chloride mother liquor as the reaction mother liquid, temperature control 90 ° C, pH control 5.0, reaction time After 5 hours, solid-liquid separation, the solid was rinsed and centrifuged to obtain 72.28 g of light green basic copper chloride crystals.

Comparative example

A method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system comprises the following steps:

S1. 2000 mL of micro-etching waste liquid containing 23.45 g/L of copper is adjusted to pH value by using 30% by weight of sodium hydroxide solution, and 49.25 g of iron scraps pulverized to 100 mesh (iron scraps are subjected to degreasing treatment) to the above In the copper waste liquid, the displacement reaction was carried out, and the reaction was carried out for 15 minutes, followed by solid-liquid separation to obtain a first solid phase and a first liquid phase, and the first solid phase was dried and pulverized to 100 mesh to obtain a sponge copper of about 81.1 g, and the copper content was 61.78%;

S3. To 81.1 g of the first solid phase after S1 treatment, 97.31 g of ammonium chloride solid and 81.1 g of the basic copper chloride production mother liquid of Example 1 were added, adjusted with ammonia water and maintained at a pH of 8.8, and heated. After the reaction to 55 ° C, the solid-liquid separation was carried out for 0.5 hours, and the obtained second solid phase was rinsed and sent to a steel smelting plant, weighing about 33.25 g; the second solid phase washing water and the remaining liquid were mixed to form 423 mL of the second liquid phase, Containing copper 116.0g / L.

S4. Dilute the hydrochloric acid with water to a concentration of 10% by weight, remove the solid impurities by filtration, react with the second liquid phase, and use 100 mL of basic copper chloride mother liquor as the reaction mother liquid, the temperature is controlled at 90 ° C, the pH value is controlled at 5.0, and the reaction time is After 5 hours, solid-liquid separation, the solid was rinsed and centrifuged to obtain 81.83 g of light green basic copper chloride crystals.

The quality of the basic copper chloride crystals obtained in the examples and comparative examples is shown in Table 5:

table 5

It can be seen from the examples and the comparative examples that after removing the oil and solidifying the toxic and harmful metals by using the white mud, the quality of the basic copper chloride product is improved, and the indexes thereof are all in line with the feed grade basic chlorination. National standard for copper. With the iron filings, the product contains high chromium because the degreasing part cannot remove the chromium.

Claims (10)

A method for recovering basic copper chloride from a copper-containing waste liquid of a sulfuric acid system, comprising the steps of: S1. Adjusting the pH of the copper-containing waste liquid in the sulfuric acid system to 2 to 2.5, adding excess iron scraps to the copper-containing waste liquid, performing a displacement reaction, and separating the solid and liquid after the reaction to obtain the first solid phase and the first Liquid phase, drying and pulverizing the first solid phase; S2. mixing the white mud slurry with the first solid phase after S1 pulverization at a mass ratio of 2 to 4:1, reacting for 2 to 3 hours, and separating the solid and liquid to obtain a second solid phase and a second liquid phase; S3. Adding 1 to 1.5 times of ammonium chloride solids and water or a mother liquor after producing basic copper chloride to the second solid phase after S2 treatment, adjusting with ammonia water and maintaining the pH value between 8 and 8.8 The reaction temperature is 45 to 55 ° C, the reaction time is 0.5 to 1 hour, and solid-liquid separation is performed to obtain a third solid phase and a third liquid phase; S4. The third liquid phase is reacted with hydrochloric acid having a mass concentration of 8 to 10%, the temperature is controlled at 75 to 90 ° C, the pH is controlled at 4.5 to 5.0, the reaction time is 2 to 5 hours, and solid-liquid separation is performed to obtain basic copper chloride. . The method of claim 1 wherein in S1 the iron filings have a size of 100 mesh. The method according to claim 1, wherein in S1, the size of the pulverized first solid phase is over 100 mesh. The method according to claim 1, wherein in S1, the pH of the first liquid phase is adjusted to 3.0 to 3.5, and hydrogen peroxide is added to carry out a Fenton reaction, and the residue after the reaction is smelted. The method of claim 1 wherein in S2, the white mud is The white mud is prepared by diluting and mixing 2 to 4 times of water. The method according to claim 1, wherein in S2, the pH of the second liquid phase is adjusted to 3.0 to 3.5, and hydrogen peroxide is added to carry out a Fenton reaction, and the residue after the reaction is smelted. The method according to claim 1, wherein in S3, the obtained third solid phase is smelted. The method according to claim 1, wherein in S4, the hydrochloric acid is derived from waste hydrochloric acid of a chemical plant. The method according to claim 1, wherein in S4, the liquid phase obtained after solid-liquid separation is used as a mother liquid after the production of basic copper chloride as described in S3; or the liquid phase obtained after solid-liquid separation is carried out. Concentrate by evaporation to recover ammonium chloride. The method according to claim 1, wherein in the white mud, the mass content of the calcium carbonate is 8 to 18%; and the mass content of the sodium carbonate is 1 to 3.5%.