Method for recycling valuable metal and fertilizer through solid waste treatment of sulfuric acid plant / steel plant

Abstract

The invention discloses a method for recycling valuable metals and fertilizers through solid waste treatment of a sulfuric acid plant / steel plant, which can separate and recycle precious metals such as gold, silver, lead, zinc, copper, iron and the like and potassium chloride fertilizers thereof through reasonable treatment procedures. Potassium chloride is separated from other solid wastes, then water and a precious metal beneficiation agent are added into filter solids obtained after first-time filter pressing, then filter pressing treatment is conducted again, gold, silver, copper and lead metal can be separated, zinc powder is added into filtrate rich in gold, silver and copper, metal replacement is conducted, filter pressing is conducted again, and the gold, silver, copper and lead are separated. The obtained filter solid is rich in gold, silver and copper precious metals, so that the gold, silver and copper precious metals are separated from other impurities of the waste solid. According to the method, the recovery efficiency of precious metals such as gold, silver, lead, zinc, copper and iron and potassium chloride thereof is high, pollution to the environment can be avoided, and waste can also be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste recovery and treatment, and in particular to a method for recovering valuable metals and fertilizers from solid waste in a sulfuric acid plant or steel mill. Background Art

[0002] The waste solids from sulfuric acid plants or steel mills usually contain a large amount of precious metals such as gold, silver, lead, zinc, copper, and iron, as well as potassium chloride, which can be used as fertilizer. Directly discharging the waste solids not only causes environmental pollution, but also causes waste. Although physical methods such as magnetic separation and gravity separation are used to recover some iron metals, the recovery of other heavy metals such as gold, silver, and their potassium chloride is ignored. Summary of the invention

[0003] Therefore, based on the above background, the present invention provides a method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill. The present invention can separate and recover precious metals such as gold, silver, lead, zinc, copper, iron and potassium chloride fertilizer through a reasonable treatment process, with high recovery efficiency, and can not only avoid pollution to the environment, but also avoid waste.

[0004] The technical solution provided by the present invention is:

[0005] A method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill comprises the following steps:

[0006] 1) Grinding solid waste from sulfuric acid plants / steel mills;

[0007] 2) Use a magnetic separator to perform magnetic separation, select the iron powder, and then add water to the solid waste and stir;

[0008] 3) Use filter press to filter the solid waste after adding water:

[0009] The solid obtained after the filtrate is treated by evaporation is potassium chloride fertilizer;

[0010] After adding water to the filtered solid again, stir it, and add precious metal beneficiation agent to it and stir until it is completely dissolved;

[0011] 4) filtering the filtered solid after adding water in step 3) using a filter press to obtain a filtered solid containing lead mud;

[0012] 5) In step 4), zinc powder is added to the filtrate obtained after the filter press treatment, and the filtrate is filtered again using a filter press to obtain a filtrate solid rich in gold, silver and copper.

[0013] Furthermore, the filtrate obtained after filtering by the filter press in step 5) is filtered through an activated carbon adsorption tower and then recycled.

[0014] Furthermore, the precious metal mineral processing agent in step 3) is selected from Jinchan gold extracting agent.

[0015] Furthermore, in step 3), the filtrate is evaporated using a triple-effect evaporator.

[0016] Furthermore, in step 1), a ball mill or a ore washer is used to grind the solid waste.

[0017] Furthermore, the particle size of the solid waste after grinding in step 1) is 150 mesh to 200 mesh.

[0018] Furthermore, in step 2), the ratio of the amount of solid waste to the amount of water added is 3:7.

[0019] Furthermore, in step 3), the ratio of the added solid to water is 3:7.

[0020] Furthermore, the amount of precious metal dressing agent added in step 3) is 3 to 10 kilograms per ton of solid waste, calculated based on the amount of solid waste in step 1).

[0021] Furthermore, in step 5), the amount of zinc powder used is 30 g to 100 g per cubic meter of the filtrate.

[0022] The above technical solution has the following beneficial effects:

[0023] The present invention can separate and recycle precious metals such as gold, silver, lead, zinc, copper, iron and potassium chloride fertilizer through reasonable processing procedures: the present invention firstly performs magnetic separation on solid waste from a sulfuric acid plant / steel mill to separate iron powder, then adds water to the magnetically separated solid waste and performs filter pressing to obtain a filtrate containing potassium chloride and a filtrate containing gold, silver, copper and lead, that is, separates potassium chloride from other solid wastes, and then evaporates the filtrate containing potassium chloride to obtain a solid that can be used as potassium chloride as a fertilizer;

[0024] Then, the filter solid after the first filter pressing is added with water and a precious metal beneficiation agent, and then subjected to filter pressing treatment again, gold, silver, copper and lead metal can be separated, the filtrate is rich in gold, silver and copper, and the filter solid is lead mud rich in lead metal;

[0025] Then, zinc powder is added to the filtrate rich in gold, silver and copper to replace the metals, and then the filtrate is filtered again. The obtained filtrate solid is rich in precious metals of gold, silver and copper, thereby separating the precious metals of gold, silver and copper from other impurities in the waste solid.

[0026] The invention has high recovery efficiency for precious metals such as gold, silver, lead, zinc, copper, iron and the like and potassium chloride thereof, which can not only avoid pollution to the environment but also avoid waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Attached Figure 1 This is a flow chart of solid waste treatment and recovery for a sulfuric acid plant / steel mill according to Example 1 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1: A method for recovering valuable metals and fertilizers from solid waste in a sulfuric acid plant / steel mill, comprising the following steps:

[0030] 1) Grind the solid waste from the sulfuric acid plant / steel plant using a ball mill or ore washer;

[0031] In specific applications, for example, waste solids from sulfuric acid slag head ash enter the hopper and are transported to the ball mill or ore washer through a conveyor belt;

[0032] In this step, the particle size of the solid waste after grinding is 150 mesh to 200 mesh.

[0033] 2) Use a magnetic separator to perform magnetic separation, select the iron powder, and then add water to the solid waste and stir;

[0034] The iron powder separated in this step is sent to an iron powder pool and then sent to a steel plant for recycling and reuse.

[0035] In this step, the ratio of solid waste to water added is 3:7.

[0036] 3) Use filter press to filter the solid waste after adding water:

[0037] The solid obtained after the filtrate is evaporated by a triple-effect evaporator is potassium chloride fertilizer, and the water vapor is cooled and collected and then recycled.

[0038] The filtered solid is stirred after adding water again (the ratio of the added amount of the filtered solid to the water is 3:7), and lime powder is added to adjust the pH to 12. The Jinchan gold extracting agent is added and stirred until it is completely dissolved; based on the amount of solid waste in step 1), the amount of Jinchan gold extracting agent added is 3 to 10 kg per ton of solid waste.

[0039] 4) filtering the solid filtered after adding water in step 3) by using a filter press to obtain a solid containing lead mud, and the obtained filtrate contains gold, silver and copper;

[0040] 5) In step 4), zinc powder is added to the filtrate containing gold, silver and copper obtained after filter pressing treatment to replace and precipitate the precious metals, and the filter solid obtained after filtering treatment again by a filter press is rich in gold, silver and copper. Finally, the filter solid is smelted into an alloy and decomposed by nitric acid to obtain gold; then, silver is obtained by precipitation with sodium chloride, and copper is replaced by iron powder. The final prepared gold purity can reach 99.8%, silver purity can reach 99.6%, and copper purity can reach 99%.

[0041] Based on the filtrate, the amount of zinc powder added is 30 to 100 grams per cubic meter.

[0042] The filtrate obtained after filtering by the filter press in this step is filtered through an activated carbon adsorption tower and then recycled.

[0043] The present invention and its implementation methods are described above, and such description is not restrictive, and the actual methods are not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design implementation methods and embodiments similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims

1. A method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill, characterized in that: The steps include: 1) Grinding solid waste from sulfuric acid plants / steel mills; 2) Use a magnetic separator to perform magnetic separation, select the iron powder, and then add water to the solid waste and stir; 3) Use filter press to filter the solid waste after adding water: The solid obtained after the filtrate is treated by evaporation is potassium chloride fertilizer; After adding water to the filtered solid again, stir it, and add an alkali agent to adjust the pH to 12; and add a precious metal beneficiation agent and stir until it is completely dissolved; 4) filtering the filtered solid after adding water in step 3) using a filter press to obtain a filtered solid containing lead mud; 5) In step 4), zinc powder is added to the filtrate obtained after the filter press treatment, and the filtrate is filtered again using a filter press to obtain a filtrate solid rich in gold, silver and copper.

2. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: The filtrate obtained after filtering by the filter press in step 5) is filtered through an activated carbon adsorption tower and then recycled.

3. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: The precious metal ore dressing agent in step 3) is selected from Jinchan gold extracting agent.

4. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: Step 3) The filtrate is evaporated using a triple-effect evaporator.

5. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: In step 1), a ball mill or a ore washer is used to grind the solid waste.

6. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: The particle size of the solid waste after grinding in step 1) is 150 mesh to 200 mesh.

7. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: In step 2), the ratio of the amount of solid waste to the amount of water added is 3:

7.

8. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: In step 3), the ratio of the added solid to water is 3:

7.

9. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: The amount of precious metal dressing agent added in step 3) is 3 to 10 kilograms per ton of solid waste, calculated based on the amount of solid waste in step 1).

10. The method for recovering valuable metals and fertilizers from solid waste treatment in a sulfuric acid plant / steel mill according to claim 1, characterized in that: In step 5), the amount of zinc powder used is 30 to 100 grams per cubic meter of the filtrate.

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