Silver electrolysis purification residue treatment method

Abstract

The invention discloses a silver electrolysis purification residue treatment method, and relates to the technical field of non-ferrous metal smelting waste treatment. The method comprises the working procedures of presoaking treatment, pressure leaching, two times of solid-liquid separation and subsequent resource recovery, wherein during presoaking, process water, anode mud, concentrated sulfuric acid, silver electrolysis purification residues and urea are added into a presoaking kettle according to the proportion, and leaching is conducted for 2-3 h while stirring is conducted at the temperature of 80-90 DEG C; putting the pre-impregnated material into a high-pressure kettle, firstly carrying out anaerobic leaching for 0-2 hours, and then introducing oxygen to carry out pressure leaching for 4-8 hours under the conditions that the temperature is 120-130 DEG C and the pressure is 0.4-0.68 Mpa; the pressurized slag is pulpified and washed and then enters an alloying furnace to be blown into a silver anode plate, the silver anode plate is sent to a silver electrolysis process, the pressurized liquid enters a normal pressure kettle, iron powder is added at the temperature of 70-80 DEG C to react for 1 h, copper powder is added at the temperature of 80-90 DEG C to react for 4-6 h, after cooling and filter pressing, filter residues are sent to tellurium for refining, and filtrate is sent to copper salt for extraction. According to the method disclosed by the invention, the processes of presoaking, pressure leaching and normal-pressure leaching are cooperated, and harmless gas is generated through nitrate radical reaction during presoaking, so that the environmental protection problem of yellow smoke emission in existing treatment is thoroughly solved.

Description

TECHNICAL FIELD

[0001] The present application relates to non-ferrous smelting waste treatment technical field, especially to a silver electrolytic purification slag treatment method. BACKGROUND

[0002] In the production of copper anode slime extraction of gold and silver, silver electrolyte is used for a period of time, the copper content increases, when the concentration reaches 20g / L, the electrolyte is used again, which will affect the quality of silver powder, causing copper and palladium in silver powder to exceed the standard, the electrolyte purification generally adopts sodium hydroxide precipitation to make copper in it form copper hydroxide precipitation, the purified electrolyte can be reused, but the purification slag cannot enter the alloy furnace for blowing because of the high copper content, and can only be added into the copper anode slime autoclave for treatment, but the autoclave liquid obtained by this method will produce a large amount of nitrogen oxide gas when the tellurium is replaced by iron powder and copper powder in the atmospheric pressure autoclave, and the atmospheric pressure autoclave uses an acid gas absorption tower which cannot absorb nitrogen oxide, so a large amount of yellow smoke directly comes out of the waste gas absorption tower, which seriously affects the environment, and with the increase of production capacity, the amount of purification slag produced is large and cannot be treated, so the silver electrolytic purification slag is all accumulated. SUMMARY

[0003] In view of the above technical problems, the present application provides a silver electrolytic purification slag treatment method to solve the problems of serious environmental pollution, low resource recovery rate and low treatment efficiency in the silver electrolytic purification slag treatment process in the prior art.

[0004] In order to achieve the above purpose, the technical scheme of the present application is as follows: A silver electrolytic purification slag treatment method, comprising the following steps: S1, water is added to a pre-leaching autoclave, and then anode slime, concentrated sulfuric acid, silver electrolytic purification slag and urea are sequentially added to the pre-leaching autoclave; after being heated to 80-90℃, the pre-leaching autoclave is started to stir and leach for 2-3h; S2, after pre-leaching, the slurry is pumped into a high-pressure autoclave and leached without oxygen for 0-2h, then oxygen is introduced after being heated to 80-90℃, and pressure leaching is carried out; S3, after the pressure is reduced to atmospheric pressure, the material is discharged into an intermediate tank for pressure filtration separation; S4, after washing, the separated pressure leaching slurry is introduced into an alloy furnace for blowing to form silver anode plates which are sent to a silver electrolysis process for use; S5, the separated pressure leaching liquid is pumped into an atmospheric pressure autoclave for atmospheric leaching; S6, after being cooled to 50-60℃, pressure filtration separation is carried out, the separated filter residue is sent to a tellurium refining link for purification of tellurium, and the filtrate is sent to a copper salt link for extraction of copper sulfate.

[0005] Further, the ratio of silver electrolytic purification residue to urea in step S1 is 5-7:1, the ratio of silver electrolytic purification residue to anode slime is 10-15:1, the water content of silver electrolytic purification residue is 20-40%, and the concentration of concentrated sulfuric acid is 150 g / L.

[0006] Further, the pressure of pressure leaching in step S2 is 0.4-0.68 MPa, the leaching temperature is 120-130 DEG C, and the leaching time is 4-8 h.

[0007] Further, the method of atmospheric leaching in step S5 is to add 80-175 kg of iron powder after heating to 70-80 DEG C, and then to add 100-125 kg of copper powder after heating to 80-90 DEG C for 4-6 h.

[0008] Compared with the prior art, the present application has the following beneficial effects: by adding urea in the pre-leaching process, the present application eliminates nitrate ions from the source, avoiding the generation of nitrogen oxides in the subsequent process; by using the process of pre-leaching-pressure leaching-atmospheric leaching, the urea reacts with the possible nitrate ions to generate harmless gas, completely solving the environmental protection problem of yellow smoke emission of nitrogen oxides during the replacement of tellurium in the atmospheric kettle in the prior treatment, and the waste gas completely meets the environmental protection emission standard; the pressure leaching is carried out in an oxygen-rich atmosphere, so that the solid carbon is fully burned, which not only improves the recovery rate of valuable metals such as silver and gold in the subsequent process, but also reduces fuel consumption; the atmospheric leaching adds iron powder and copper powder in stages, first reduces high-valence ions to protect copper powder, and then efficiently replaces tellurium, which guarantees the high recovery rate of tellurium, and the copper sulfate extracted from the filtrate has high purity and can be directly used as a product or raw material. The present application does not have accumulated materials, can reduce costs and increase efficiency, and can recover silver from silver electrolytic purification residue by using the original copper anode slime treatment equipment without increasing equipment and personnel, greatly reducing production costs, and having good applicability. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The process flow chart of the present application is shown in the figure. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical scheme and advantages of the present application clearer and more explicit, the present application will be further described in detail below with specific embodiments. It should be understood that these descriptions are only exemplary and do not limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0011] Example 1, A silver electrolytic purification residue treatment method comprises the following steps: S1, add water 24 m 3Then, the anode slime 6t, concentrated sulfuric acid 4t, silver electrolytic purification residue 0.6kg, and urea 100kg are sequentially added into the pre-dipping kettle; after being heated to 80℃, the pre-dipping kettle is started to stir and leach for 2h; S2, after pre-dipping, the material is pumped into an autoclave, heated to 80℃, oxygen is introduced, and pressure leaching is performed at a pressure of 0.4MPa; the leaching temperature is 120℃, and the leaching time is 4h; S3, after being depressurized to normal pressure, the material is discharged into an intermediate tank for pressure filtration separation; S4, after being separated, the pressure residue slurry is washed and then enters an alloy furnace, is blown into silver anode plates, and is sent to a silver electrolysis process for use; S5, the separated pressure liquid is pumped into a normal pressure kettle for normal pressure leaching; after being heated to 70℃, 80kg of iron powder is added for reaction for 1h; after being heated to 90℃ again, 100kg of copper powder is added for reaction for 4.5h; S6, after being cooled to 50℃, pressure filtration separation is performed; the separated filter residue is sent to a tellurium refining link for purification of tellurium; the filter residue contains gold and silver 3g / t; and the filtrate is sent to a copper salt link for extraction of copper sulfate. The entire normal pressure leaching does not generate yellow smoke, and the waste gas is environmentally friendly.

[0012] Example 2, A silver electrolytic purification residue treatment method, comprising the following steps: S1, water 28m 3 Then, the anode slime 6t, concentrated sulfuric acid 4t, silver electrolytic purification residue 0.6kg, and urea 100kg are sequentially added into the pre-dipping kettle; after being heated to 80℃, the pre-dipping kettle is started to stir and leach for 2h; S2, after pre-dipping, the material is pumped into an autoclave, heated to 80℃, oxygen is introduced, and pressure leaching is performed at a pressure of 0.4MPa; the leaching temperature is 120℃, and the leaching time is 4h; S3, after being depressurized to normal pressure, the material is discharged into an intermediate tank for pressure filtration separation; S4, after being separated, the pressure residue slurry is washed and then enters an alloy furnace, is blown into silver anode plates, and is sent to a silver electrolysis process for use; S5, the separated pressure liquid is pumped into a normal pressure kettle for normal pressure leaching; after being heated to 70℃, 80kg of iron powder is added for reaction for 1h; after being heated to 90℃ again, 100kg of copper powder is added for reaction for 4.5h; S6, after being cooled to 50℃, pressure filtration separation is performed; the separated filter residue is sent to a tellurium refining link for purification of tellurium; the filter residue contains gold and silver 3g / t; and the filtrate is sent to a copper salt link for extraction of copper sulfate. The entire normal pressure leaching does not generate yellow smoke, and the waste gas is environmentally friendly.

[0013] Example 3, A silver electrolytic purification residue treatment method, comprising the following steps: S1, water 28m3 Then, 7.2 tons of anode slime, 4.84 tons of concentrated sulfuric acid, 0.6 kg of silver electrolytic purification residue, and 100 kg of urea were sequentially added into the pre-dipping kettle; after being heated to 90°C, the pre-dipping kettle was started to stir and leach for 3 hours; S2, after pre-dipping, the material was pumped into an autoclave and subjected to oxygen-free leaching for 2 hours; then, the temperature was increased to 90°C, oxygen was introduced, and pressure leaching was performed at a pressure of 0.68 MPa; the leaching temperature was 130°C, and the leaching time was 8 hours; S3, after the pressure was reduced to normal pressure, the material was discharged into an intermediate tank and subjected to pressure filtration separation; S4, after separation, the pressure residue slurry was washed and then entered an alloy furnace, where it was blown into silver anode plates and sent to a silver electrolysis process; S5, the separated pressure liquid was pumped into a normal pressure kettle and subjected to normal pressure leaching; after being heated to 80°C, 175 kg of iron powder was added and reacted for 1 hour; then, after being heated to 90°C again, 125 kg of copper powder was added and reacted for 6 hours; S6, after being cooled to 60°C, the material was subjected to pressure filtration separation; the separated filter residue was sent to a tellurium refining link for purification of tellurium; the filter residue contained 4 g / t of gold and silver; and the filtrate was sent to a copper salt link for extraction of copper sulfate. The entire normal pressure leaching process did not generate yellow smoke, and the waste gas met the environmental protection standards.

[0014] A certain copper company used a new treatment method to process all of its silver electrolytic purification residue; in 2023, 15.5 tons of silver electrolytic purification residue were processed, and 2.5 tons of silver were recovered; in 2024, 25 tons of silver electrolytic purification residue were processed, and 3.75 tons of silver were recovered; the intermediate material inventory was reduced, the production cost was reduced, and the economic benefits were increased by 15-30 million yuan per year.

[0015] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes, and do not constitute a limitation on the present application. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for treating silver electrolytic purification residue, characterized in that, Includes the following steps: S1. Add water to the pre-soaking kettle, then add anode mud, concentrated sulfuric acid, silver electrolysis purification residue and urea in sequence; after heating to 80℃~90℃, start the pre-soaking kettle to stir and leach for 2-3 hours. S2. After pre-soaking, pump the solution into an autoclave. After 0-2 hours of anaerobic leaching, raise the temperature to 80℃-90℃ and then introduce oxygen for pressurized leaching. S3. After depressurization to atmospheric pressure, the material is discharged into the intermediate tank for pressure filtration separation. S4. After separation, the pressurized slurry is washed and then fed into an alloy furnace, where it is blown into silver anode plates and sent to the silver electrolysis process. S5. The separated pressurized liquid is pumped into an atmospheric pressure vessel for atmospheric pressure leaching. S6. After cooling to 50-60℃, pressure filtration is performed. The separated filter residue is sent to the tellurium refining stage to purify tellurium, and the filtrate is sent to the copper salt stage to extract copper sulfate.

2. The method for treating silver electrolytic purification residue according to claim 1, characterized in that, In step S1, the ratio of silver electrolytic purification residue to urea is 5-7:1, the ratio of silver electrolytic purification residue to anode mud is 10-15:1, the water content of silver electrolytic purification residue is 20-40%, and the concentration of concentrated sulfuric acid is 150g / L.

3. The method for treating silver electrolytic purification residue according to claim 1, characterized in that, The pressure for step S2, the leaching pressure, is 0.4-0.68 MPa, the leaching temperature is 120℃-130℃, and the leaching time is 4-8 hours.

4. The method for treating silver electrolytic purification residue according to claim 1, characterized in that, The method for atmospheric pressure leaching in step S5 is to heat the temperature to 70℃-80℃, add 80-175kg of iron powder and react for 1 hour, then heat the temperature again to 80℃-90℃ and add 100-125kg of copper powder and react for 4-6 hours.

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