Method for recovering nearly all elements in low-precious-metal zinc replacement powder

Abstract

The invention discloses a method for recovering nearly all elements in low-precious-metal zinc replacement powder, which belongs to the technical field of non-ferrous metal wet smelting, and comprises the following steps: preparing zinc replacement powder, oxidizing and leaching, extracting copper, preparing cuprous chloride, electrodepositing zinc in raffinate, extracting precious metal by using a gold extracting agent, extracting, reducing and smelting to prepare a gold ingot and a silver ingot, and dissolving by using sodium hydroxide. Preparing lead carbonate; carrying out oxidation acid leaching; replacing; and smelting bismuth. According to the technology for achieving recovery and high-value utilization of nearly all elements in the zinc replacement powder under the mild condition, the technology can be carried out at the normal temperature, the high-pressure condition does not need to be provided, the zinc replacement powder is leached through the acid solution, then various valuable metals are selectively extracted from the leaching solution, corresponding downstream products are prepared, and the method is suitable for industrial production. The method realizes value maximization, does not generate secondary pollution, does not introduce fluorine, has low requirements on equipment, is simple in process and easy to operate, and makes up for the defects of the zinc replacement powder treatment process in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrometallurgy of non-ferrous metals, and particularly relates to a method for nearly total element recovery from low-precious metal zinc replacement powder. Background Art

[0002] Hydrometallurgy is a method in which ores, beneficiated concentrates or other raw materials enriched by ore dressing are contacted with an aqueous solution or other liquid, and through chemical reactions, etc., the valuable metals contained in the raw materials are transferred into the liquid phase, and then various valuable metals contained in the liquid phase are separated and enriched, and finally recovered in the form of metals or other compounds. One of the very important steps in hydrometallurgy is to extract valuable metals from the solution. At present, the methods for extracting metals from the solution are mainly divided into electrolysis and chemical methods. Among them, the chemical methods mainly include hydrogenation reduction method, sulfur dioxide reduction method, ferrous reduction method, replacement method, etc. Considering that the standard electrode potential of zinc is -0.763V, it can reduce the metals with negative electrode potential, and it is a commonly used replacement agent and one of the preferred replacement agents for recovering and enriching valuable metals in low-precious metal feed solutions.

[0003] At present, the treatment of zinc replacement powder is mainly used to recover elements such as iron, copper, and zinc in the zinc replacement powder. The treatment methods include conventional acid leaching, pressure oxidation acid leaching, etc. By leaching one or several elements in the zinc replacement powder into the solution, and then extracting the valuable metals by extraction. However, this method often only targets a certain specific element, and the recovery and utilization of other elements are not high, and the equipment requirements are high, making it difficult to achieve industrialization, resulting in waste of resources.

[0004] Chinese Patent CN 117845078 A discloses "A Method for Recovering Indium from Zinc Replacement Residue". After steps such as acid leaching, reduction, and extraction, indium recovery is achieved. However, this method has high equipment requirements, a long operation process, and only targets indium in zinc replacement residue, without mentioning the recovery and utilization of other valuable metals, resulting in waste of resources. Chinese Patent CN114318017 A discloses "A Method for Deep Leaching of Zinc, Copper, Gallium, and Germanium from Zinc Replacement Residue". This process uses two-stage acid leaching and can achieve a leaching rate of more than 95% for zinc, copper, gallium, and germanium. However, this method has high equipment requirements and only mentions the leaching of several elements, without covering the separation and utilization of valuable metals in it, and the process is incomplete and unable to realize economic value. Chinese Patent CN 113430387 A discloses "A Method for Total Extraction and Separation of Gallium, Iron, and Zinc from Sulfuric Acid Leaching Solution of Zinc Replacement Residue", which can achieve a recovery rate of more than 99% for gallium and iron and more than 85% for zinc. However, this method uses a large amount of extractant, has a complex operation, and a high cost, which is not conducive to large-scale production. Chinese Patent CN 106834692A discloses "A Comprehensive Recovery Method for Valuable Metals in Zinc Powder Replacement Residue". This method performs leaching under high temperature and high pressure. Although a high leaching rate can be obtained, it has high equipment requirements, a large investment, and high energy consumption. At the same time, it does not mention the treatment of heavy metals such as cadmium and chromium, and the enrichment of these heavy metals in the system will affect the leaching efficiency and reduce the comprehensive recovery rate.

[0005] In summary, the current treatment processes for zinc replacement powder have the following deficiencies: 1. Only the leaching step or the extraction and purification step is considered, and a complete process for treating zinc replacement powder is not mentioned. Only one or a few elements are targeted, and the valuable elements are not comprehensively utilized. 2. For the recovery and utilization of valuable elements, extraction is basically used, a large amount of extractant is used, the working environment is harsh, and the extractant is expensive, resulting in a high cost, which is not conducive to large-scale production. 3. The treatment of heavy metals such as chromium, cadmium, and thallium is not mentioned, which will cause secondary pollution.

[0006] The present invention provides a process for realizing the high-value utilization of nearly all elements in zinc replacement powder under mild conditions. It can be carried out at room temperature without the need to provide high-pressure conditions. An acid solution is used to leach zinc replacement powder, and then various valuable metals are selectively extracted from the leaching solution and made into corresponding downstream products to maximize value, without generating secondary pollution, and without introducing fluorine. It has low equipment requirements, a simple process, and is easy to operate, making up for the deficiencies of the existing technical means for treating zinc replacement powder. Summary of the Invention

[0007] The present invention provides a process for nearly complete element recovery and high-value utilization of low-precious-metal zinc replacement powder, which is used to recover and utilize elements such as gold, silver, copper, lead, zinc, and thallium in the zinc replacement powder, realizing the maximum utilization of value and avoiding waste of resources.

[0008] To achieve the above technical objectives, the technical solution of the present invention is as follows:

[0009] The present invention provides a method for nearly complete element recovery from low-precious-metal zinc replacement powder. The technical solution is: zinc replacement powder → oxidative leaching → copper extraction by solvent extraction, preparation of cuprous chloride, electrowinning zinc from raffinate → extraction of precious metals with a gold extractant, extraction, reduction and melting to produce gold ingots and silver ingots → dissolution with sodium hydroxide to prepare lead carbonate → oxidative acid leaching → replacement → smelting of bismuth.

[0010] It includes the following steps:

[0011] (1) Take low-precious-metal zinc replacement powder, dissolve it with an acid solution, and add an oxidant during dissolution. Keep the dissolution process at room temperature for 1 - 3 h to ensure the leaching rate of metals such as zinc, copper, and thallium. After solid-liquid separation, a copper-containing solution and acid-soluble solids are obtained.

[0012] (2) First, use an extractant to selectively enrich copper in the copper-containing solution obtained in step (1) to obtain a zinc-containing solution and a copper-rich organic phase, and then perform back-extraction with a back-extraction solution to obtain a copper sulfate solution. Add sodium chloride and a reducing agent to the obtained copper sulfate solution to prepare cuprous chloride, or use it for electrowinning copper to prepare copper powder. Add zinc powder to the zinc-containing solution obtained after extraction for replacement. The dosage of zinc powder is 0.1 - 1 g / L, and the replacement time is 0.5 - 1 h. Then, after solid-liquid separation, a zinc sulfate solution and zinc replacement powder are obtained. The zinc sulfate solution is used to prepare crude zinc hydroxide by adding ammonium bicarbonate and ammonium chloride, and then zinc powder is prepared by reduction roasting or zinc powder is prepared by electrowinning zinc. The zinc replacement powder is returned to step (1) for recycling.

[0013] (3) Add a gold extractant to the acid-soluble solids obtained in step (1) to leach gold and silver in the acid-soluble solids. Ensure that the liquid-solid ratio is 5 - 10:1 during leaching, the leaching time is 24 - 48 h, the leaching pH is 10 - 14, and the leaching temperature is 25 - 35 °C. After the reaction, solid-liquid separation is carried out to obtain a gold-containing solution and lead-containing solids.

[0014] (4) The gold-containing solution obtained in step (3) is extracted with a first organic phase, the first organic phase is washed with 0.5 - 1 mol / L dilute hydrochloric acid, and sodium sulfite solution is used for back-extracting gold to obtain a silver-containing solution and sponge gold. The sponge gold is melted at 1100 - 1300 °C to produce gold ingots; the silver-containing solution is extracted with a second organic phase, or ammonium ferrous sulfate with a mass fraction of 10 - 20% is added to the silver-containing solution and then extracted with the second organic phase. Then, the second organic phase is washed with 0.5 - 1 mol / L nitric acid, and then hydrazine hydrate or glucose solution is used for back-extracting to obtain sponge silver. The sponge silver is melted at 1000 - 1200 °C to produce silver ingots;

[0015] (5) The lead-containing solid obtained in step (3) is dissolved with an alkali solution. After solid-liquid separation, a lead-containing solution and an alkali-soluble solid are obtained. The dissolution process is maintained at 50 - 90 °C, and the dissolution time is 1 - 3 h;

[0016] (6) A precipitant is added to the lead-containing solution obtained in step (5) to prepare lead carbonate products, and the reaction time is 1 - 3 h;

[0017] (7) The alkali-soluble solid obtained in step (5) is dissolved with an acid solution. An oxidant is added during the dissolution process, and a displacement agent is added after dissolution is completed. After dissolution is completed, a displacement agent is used for displacement to obtain crude bismuth, and then high-temperature melting at 600 - 800 °C is used to prepare bismuth ingots.

[0018] Among them, in step (1), the acid solution is sulfuric acid or hydrochloric acid with a concentration of 2 - 5 mol / L, and the oxidant is sodium peroxide, hydrogen peroxide, calcium hypochlorite or sodium hypochlorite.

[0019] Among them, in step (2), the extractant consists of N902 and sulfonated kerosene, and the mass concentration of N902 is 20 - 30%, or the extractant consists of β-naphthalene sulfonic acid, N902 and sulfonated kerosene, the mass concentration of β-naphthalene sulfonic acid is 1 - 3%, the mass concentration of N902 is 20 - 30%, the back-extraction solution used is 1 - 4 mol / L sulfuric acid solution; the ratio of the addition amount of sodium chloride to the amount of copper ions in the copper sulfate solution is 1 - 2:1, and the reducing agent is one or more of sulfur dioxide, sodium sulfite, copper powder. The addition amount of the reducing agent is 1 - 2:1, the reduction temperature is maintained at 50 - 90 °C, the reduction time is 1 - 3 h, and after reduction is completed, solid-liquid separation is performed to obtain cuprous chloride solid.

[0020] Among them, in step (4), the first organic phase consists of dibutyl carbitol and sulfonated kerosene; the second organic phase consists of diisooctyl sulfide and sulfonated kerosene.

[0021] Among them, in step (5), the alkali solution is one or more of sodium hydroxide or potassium hydroxide, the concentration of the alkali solution used is 5 - 10 mol / L, and the liquid-solid ratio is 2 - 5:1.

[0022] Among them, in step (6), the precipitating agent used is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, sodium hydroxide, and carbon dioxide.

[0023] Among them, in step (7), the acid solution is hydrochloric acid or sulfuric acid, the concentration of the acid solution is 2 - 5 mol / L, the liquid-solid ratio is 2 - 5:1, the temperature is 50 - 80 °C, and the dissolution time is 3 - 5 h; the oxidizing agent used is one or more of hydrogen peroxide, ferric chloride, sulfuric acid, and chlorine, and the addition amount of the oxidizing agent is 15 - 30 g / L; the displacing agent used is zinc powder, iron powder, or lead powder, the addition amount of the displacing agent is 5 - 10 g / L, and the displacement time is 0.5 - 1.5 h.

[0024] Compared with the prior art, the technical effects of the present invention are as follows:

[0025] The present invention uses the method of oxidative leaching to treat zinc replacement powder, adopts stepwise leaching, mainly leaches one metal ion in each step to obtain a leaching solution containing almost only this kind of ion, and then uses methods such as extraction and reduction for recovery and preparation of downstream products, realizing nearly complete element recovery and high-value utilization of zinc replacement powder. Moreover, this process has simple operation, is easy to implement, has low requirements for equipment, and makes up for the deficiencies of the prior art in treating zinc replacement powder. Detailed Embodiments

[0026] The following embodiments are provided to better understand the present invention. They are not limited to the best embodiment, do not constitute a limitation to the content and protection scope of the present invention, and any product obtained by combining the present invention with other prior art features or inspired by the present invention that is the same as or similar to the present invention falls within the protection scope of the present invention.

[0027] Example 1

[0028] The main components of a low-precious-metal zinc replacement powder are shown in Table 1:

[0029] Table 1 Composition of a low-precious-metal zinc replacement powder

[0030]

[0031] According to the component analysis of the zinc replacement powder in Table 1, sulfuric acid solution is used to dissolve zinc and copper in the zinc replacement powder. The concentration of the sulfuric acid solution used is 2 mol / L, the liquid-solid ratio is 1:1, hydrogen peroxide is added as an oxidizing agent during dissolution, the addition amount of the oxidizing agent is 10%, the dissolution process is carried out at room temperature, and the dissolution time is 1 h. After the reaction is completed, solid-liquid separation is carried out to obtain a copper-containing solution and acid-soluble solids. The composition of the copper-containing solution is shown in Table 2.

[0032] Table 2 Composition of the copper-containing solution

[0033]

[0034] As can be seen from the data in Table 2, sulfuric acid dissolution mainly targets zinc and copper in the zinc replacement powder, with leaching rates of 93.1% and 95.5% respectively. In addition, a small amount of thallium is also leached out, with a thallium leaching rate of 67.2%. To realize the high-value utilization of copper in the copper-containing solution, the copper in the copper-containing solution is selectively enriched using the extractant first to obtain a zinc-containing solution and a copper-rich organic phase, and then 2 mol / L sulfuric acid is used for stripping to obtain a copper sulfate solution. The extractant used in this process consists of N902 and sulfonated kerosene. The mass concentration of N902 is 20%, the O / A ratio is 1:1, the extraction time is 10 min, and the extraction rate is 96.3%. Then, sodium chloride and a reducing agent are added to the copper sulfate solution after stripping. The addition amount of sodium chloride is 1:1 with the copper ions in the solution. The reducing agent sulfur dioxide is added for reduction at 50 °C (the addition amount of sulfur dioxide is 1:1 with the copper ions in the solution). After reacting for 1 h, solid-liquid separation is carried out to obtain cuprous chloride, realizing the recovery and high-value utilization of copper. At this time, the main component in the zinc-containing solution is zinc sulfate, but there are also a small amount of heavy metals such as thallium. Therefore, zinc powder is added to the zinc-containing solution for replacement. The addition amount of zinc powder is 0.1 g / L. The zinc-containing solution after replacement is subjected to zinc electrowinning, and the solid is returned to the first step for dissolution. The composition of the acid-soluble solid is shown in Table 3.

[0035] Table 3 Composition of Acid-Soluble Solid

[0036]

[0037] The gold and silver in the acid-soluble solid are leached using a gold leaching agent (this gold leaching agent is commercially available). During leaching, the liquid-solid ratio is ensured to be 5:1, the leaching time is 24 h, the leaching pH is 10, the leaching temperature is 25 °C. After the reaction ends, solid-liquid separation is carried out to obtain a gold-containing solution and a lead-containing solid. The gold-containing solution is extracted with the first organic phase to obtain a gold-rich organic phase and a silver-containing solution. The extractant used for extraction is dibutyl carbitol and sulfonated kerosene, and the extraction rate is 99.01%. The first organic phase is washed with 0.5 mol / L dilute hydrochloric acid, and gold is reduced using a sodium sulfite solution. The addition amount of sodium sulfite is 0.5:1 with the gold ions in the solution. After smelting at 1100 °C, a gold ingot is obtained. The silver-containing solution is extracted with the second organic phase. The extractant used is diisooctyl sulfide and sulfonated kerosene, and the extraction rate is 99.05%. The second organic phase is washed with 0.5 mol / L nitric acid, and then silver is stripped using a glucose solution. The addition amount of glucose is 1:1 with the silver ions in the solution. After smelting at 1000 °C, a silver ingot is obtained.

[0038] The composition of the lead-containing solid is shown in Table 4.

[0039] Table 4 Composition of Lead-Containing Solid

[0040]

[0041] As can be seen from the data in Table 4, the main component of the lead-containing solid is lead sulfate. Sodium hydroxide solution is used for dissolution. The concentration of the sodium hydroxide solution used is 5 mol / L, the liquid-solid ratio is 5:1, the dissolution temperature is maintained at 50 °C, and the dissolution time is 1 h. After the reaction is complete, solid-liquid separation is carried out to obtain a lead-containing liquid and an alkali-soluble solid. The main component composition of the lead-containing liquid is shown in Table 5:

[0042] Table 5 Composition of the lead-containing solution

[0043]

[0044] As can be seen from the data in Table 5, the main component of the lead-containing solution is lead ions, and the concentration of OH - ions in the solution is very high. To realize the high-value utilization of lead in the lead-containing solution, CO 2 is introduced into the lead-containing solution as a precipitant. After stirring and precipitating for 1 h, solid-liquid separation is carried out to obtain lead carbonate products. The composition of the alkali-soluble solid is shown in Table 6 below:

[0045] Table 6 Composition of the alkali-soluble solid

[0046]

[0047] Calculated from the data in Table 6, the lead dissolution rate is 71.3%. The alkali-soluble solid is dissolved with 2 mol / L sulfuric acid solution. 15 g of ferric chloride is added during the dissolution process. The liquid-solid ratio is maintained at 2:1, and stirring and dissolution are carried out at 50 °C for 3 h. After the dissolution is completed, 5 g / L of lead powder is added for replacement. After replacement at room temperature for 0.5 h, solid-liquid separation is carried out to obtain crude bismuth, and then melting and refining are carried out at 600 °C to obtain bismuth ingots.

[0048] Example 2

[0049] The main components of a low-precious-metal zinc replacement powder are shown in Table 7:

[0050] Table 7 Composition of a low-precious-metal zinc replacement powder

[0051]

[0052] According to the component analysis of the zinc replacement powder in Table 7, sulfuric acid solution is used to dissolve zinc and copper in the zinc replacement powder. The concentration of the sulfuric acid solution used is 4 mol / L, the liquid-solid ratio is 4:1, and calcium hypochlorite is added as an oxidant during dissolution. The addition amount of calcium hypochlorite is 12%. The dissolution process is carried out at room temperature, and the dissolution time is 2 h. After the reaction is complete, solid-liquid separation is carried out to obtain a copper-containing solution and an acid-soluble solid. The composition of the copper-containing solution is shown in Table 8.

[0053] Table 8 Composition of the copper-containing solution

[0054]

[0055] As can be seen from the data in Table 8, the sulfuric acid dissolution process mainly targets zinc and copper in the zinc replacement powder, and the leaching rate can reach over 99%. In addition, there are also small amounts of heavy metal elements such as thallium. To realize the high-value utilization of copper in the copper-containing solution, the copper in the copper-containing solution is selectively enriched by the extractant first to obtain a zinc-containing solution and a copper-rich organic phase, and then 1 mol / L sulfuric acid is used for back-extraction to obtain a copper sulfate solution. The extractant used in this process consists of N902 and sulfonated kerosene. The mass concentration of N902 is 30%, the O / A ratio is 2:1, the extraction time is 20 min, and the extraction rate is 96.2%. Then, sodium chloride and a reducing agent are added to the copper sulfate solution after back-extraction. The addition amount of sodium chloride is 1.5:1 compared with the copper ions in the solution. The reducing agent sodium sulfite is added for reduction at 70 °C (the addition amount of sodium sulfite is 2:1 compared with the copper ions in the solution). After reacting for 1.5 h, solid-liquid separation is carried out to obtain cuprous chloride, realizing the recovery and high-value utilization of copper. At this time, the main component in the zinc-containing solution is zinc sulfate, but there are also small amounts of heavy metals such as thallium. Therefore, zinc powder is added to the zinc-containing solution for replacement. The addition amount of zinc powder is 0.5 g / L. After replacement, solid-liquid separation is carried out. The solid is returned to the first step for dissolution, and the liquid can be used for zinc electrowinning. The composition of the acid-soluble solid is shown in Table 9.

[0056] Table 9 Composition of Acid-Soluble Solid

[0057]

[0058]

[0059] The gold and silver in the acid-soluble solid are leached using a gold leaching agent. When leaching, ensure that the liquid-solid ratio is 8:1, the leaching time is 36 h, the leaching pH is 13, and the leaching temperature is 30 °C. After the reaction, solid-liquid separation is carried out to obtain a gold-containing solution and a lead-containing solid. The gold-containing solution is extracted with the first organic phase, and the extraction rate is 99.04% to obtain a gold-rich organic phase and a silver-containing solution. The extractant used for extraction is dibutyl carbitol and sulfonated kerosene, and the extraction rate is 97.2%. The first organic phase is washed with 0.8 mol / L dilute hydrochloric acid, and gold is reduced using a sodium sulfite solution. The addition amount of sodium sulfite is 1:1 compared with the gold ions in the solution. After smelting at 1200 °C, a gold ingot is obtained. The silver-containing solution is extracted with the second organic phase, and the extraction rate is 99.01%. The extractant used is diisooctyl sulfide and sulfonated kerosene. The second organic phase is washed with 0.8 mol / L nitric acid, and then silver is back-extracted using a hydrazine hydrate solution. The addition amount of hydrazine hydrate is 1.5:1 compared with the silver ions in the solution. After smelting at 1100 °C, a silver ingot is obtained. The composition of the lead-containing solid is shown in Table 10 below.

[0060] Table 10 Composition of Lead-Containing Solid

[0061]

[0062] As can be seen from the data in Table 10, the main component in the lead-containing solid is lead sulfate. Potassium hydroxide solution is used for dissolution. The concentration of the potassium hydroxide solution used is 8 mol / L, the liquid-solid ratio is 8:1, the dissolution temperature is maintained at 70 °C, and the dissolution time is 2 h. After the reaction is complete, solid-liquid separation is carried out to obtain a lead-containing liquid and an alkali-soluble solid. The main component composition of the lead-containing liquid is shown in Table 11:

[0063] Table 11 Composition of the lead-containing liquid

[0064]

[0065] As can be seen from the data in Table 11, the main component in the lead-containing solution is lead ions, and the concentration of OH - ions in the solution is very high. To achieve high-value utilization of lead in the lead-containing solution, sodium bicarbonate is added as a precipitant to the lead-containing solution. After stirring and precipitating for 1.5 h, solid-liquid separation is carried out to obtain lead carbonate products. The composition of the alkali-soluble solid is as shown in Table 12:

[0066] Table 12 Composition of the alkali-soluble solid

[0067]

[0068]

[0069] Calculated from the data in Table 12, the lead dissolution rate is 86%. The alkali-soluble solid is dissolved with 4 mol / L hydrochloric acid solution. 25 g of hydrogen peroxide is added during the dissolution process, the liquid-solid ratio is maintained at 4:1, and it is stirred and dissolved at 70 °C for 4 h. After the dissolution is completed, zinc powder with a concentration of 8 g / L is added for replacement. After replacement at room temperature for 0.8 h, solid-liquid separation is carried out to obtain crude bismuth, and then it is melted and refined at 700 °C to obtain bismuth ingots.

[0070] Example 3

[0071] The main components of a low-precious-metal zinc replacement powder are shown in Table 13:

[0072] Table 13 Composition of a low-precious-metal zinc replacement powder

[0073]

[0074] According to the component analysis of the zinc replacement powder in Table 13, hydrochloric acid is used to dissolve zinc and copper in the zinc replacement powder. The concentration of the hydrochloric acid used is 5 mol / L, the liquid-solid ratio is 5:1, sodium peroxide is added as an oxidant during dissolution, the addition amount of sodium peroxide is 15%, the dissolution process is carried out at room temperature, and the dissolution time is 3 h. After the reaction is complete, solid-liquid separation is carried out to obtain a copper-containing solution and an acid-soluble solid. The composition of the copper-containing solution is shown in Table 14.

[0075] Table 14 Composition of the copper-containing solution

[0076]

[0077] As can be seen from the data in Table 14, the sulfuric acid dissolution process mainly targets zinc and copper in the zinc replacement powder, and the leaching rate can reach over 99%. In addition, there are also small amounts of heavy metal elements such as thallium. To achieve high-value utilization of copper in the copper-containing solution, the copper in the zinc-containing solution is selectively enriched using an extractant first to obtain a zinc-containing solution and a copper-rich organic phase, and then 4 mol / L sulfuric acid is used for back-extraction to obtain a copper sulfate solution. The extractant used in this process consists of N902 and sulfonated kerosene. The mass concentration of N902 is 25%, the O / A ratio is 3:1, the extraction time is 30 min, and the extraction rate is 95.8%. Then, sodium chloride and a reducing agent are added to the copper sulfate solution after back-extraction. The addition amount of sodium chloride is 2:1 compared to the copper ions in the solution. The reducing agent copper powder is added and reduced at 90 °C (the addition amount of copper powder is 2:1 compared to the copper ions in the solution). After reacting for 3 h, solid-liquid separation is carried out to obtain cuprous chloride, realizing the recovery and high-value utilization of copper. At this time, the main component in the zinc-containing solution is zinc sulfate, but there are also small amounts of heavy metals such as thallium. Therefore, zinc powder is added to the zinc-containing solution for replacement. The addition amount of zinc powder is 1 g / L. After replacement, solid-liquid separation is carried out. The solid is returned to the first step for dissolution, and the liquid can be used for zinc electrowinning. The composition of the acid-soluble solid is shown in Table 15.

[0078] Table 15 Composition of the acid-soluble solid

[0079]

[0080] The gold and silver in the acid-soluble solid are leached using a gold leaching agent. During leaching, the liquid-solid ratio is ensured to be 10:1, the leaching time is 48 h, the leaching pH is 14, and the leaching temperature is 35 °C. After the reaction, solid-liquid separation is carried out to obtain a gold-containing solution and a lead-containing solid. The gold-containing solution is extracted with the first organic phase, and the extraction rate is 89.96% to obtain a gold-rich organic phase and a silver-containing solution. The extractant used for extraction is dibutyl carbitol and sulfonated kerosene. The first organic phase is washed with 1 mol / L dilute hydrochloric acid, and sodium sulfite solution is used to reduce gold. The addition amount of sodium sulfite is 1.5:1 compared to the gold ions in the solution. After smelting at 1300 °C, a gold ingot is obtained. The silver-containing solution is extracted with the second organic phase, and the extraction rate is 99.04%. The extractant used is diisooctyl sulfide and sulfonated kerosene. The second organic phase is washed with 0.8 mol / L nitric acid, and then glucose solution is used for back-extracting silver. The addition amount of glucose is 2:1 compared to the silver ions in the solution. After smelting at 1200 °C, a silver ingot is obtained. The composition of the lead-containing solid is shown in Table 16 below.

[0081] Table 16 Composition of the lead-containing solid

[0082]

[0083] As can be seen from the data in Table 16, the main component of the lead-containing solid is lead sulfate. Sodium hydroxide solution is used for dissolution. The concentration of the sodium hydroxide solution used is 10 mol / L, the liquid-solid ratio is 10:1, the dissolution temperature is maintained at 90 °C, and the dissolution time is 3 h. After the reaction is complete, solid-liquid separation is carried out to obtain a lead-containing liquid and an alkali-soluble solid. The main component composition of the lead-containing liquid is shown in Table 17:

[0084] Table 17 Composition of the lead-containing solution

[0085]

[0086] As can be seen from the data in Table 17, the main component of the lead-containing solution is lead ions, and the concentration of OH - ions in the solution is very high. Therefore, in order to realize the high-value utilization of lead in the lead-containing solution, sodium carbonate is added as a precipitant to the lead-containing solution. After stirring and precipitating for 3 h, solid-liquid separation is carried out to obtain lead carbonate products. The composition of the alkali-soluble solid is shown in Table 18 below:

[0087] Table 18 Composition of the alkali-soluble solid

[0088]

[0089] Calculated from the data in Table 18, the lead dissolution rate is 87%. The alkali-soluble solid is dissolved with 5 mol / L hydrochloric acid solution. Chlorine gas is introduced during the dissolution process, and the liquid-solid ratio is maintained at 5:1. Stir and dissolve at 80 °C for 5 h. After the dissolution is completed, iron powder with a concentration of 10 g / L is added for replacement. After replacement at room temperature for 1.5 h, solid-liquid separation is carried out to obtain crude bismuth, and then molten refining is carried out at 800 °C to obtain bismuth ingots.

[0090] Example 4

[0091] The main components of a low-precious-metal zinc replacement powder are shown in Table 19:

[0092] Table 19 Composition of a low-precious-metal zinc replacement powder

[0093]

[0094] According to the component analysis of the zinc replacement powder in Table 19, sulfuric acid solution is used to dissolve zinc and copper in the zinc replacement powder. The concentration of the sulfuric acid solution used is 3 mol / L, the liquid-solid ratio is 1:1, hydrogen peroxide is added as an oxidant during dissolution, the addition amount of the oxidant is 10%, the dissolution process is carried out at room temperature, and the dissolution time is 1 h. After the reaction is complete, solid-liquid separation is carried out to obtain a copper-containing solution and an acid-soluble solid. The composition of the copper-containing solution is shown in Table 20.

[0095] Table 20 Composition of the copper-containing solution

[0096]

[0097] As can be seen from the data in Table 20, sulfuric acid dissolution mainly targets zinc and copper in the zinc replacement powder, and their leaching rates are 93.0% and 95.8% respectively. In addition, a small amount of thallium is also leached out, and the thallium leaching rate is 65.6%. To realize the high-value utilization of copper in the copper-containing solution, the copper in the copper-containing solution is selectively enriched by the extractant first to obtain a zinc-containing solution and a copper-rich organic phase, and then 2 mol / L sulfuric acid is used for back-extraction to obtain a copper sulfate solution. The extractant used in this process is composed of β-naphthalene sulfonic acid, N902 and sulfonated kerosene. The mass concentration of β-naphthalene sulfonic acid is 1.5%, the mass concentration of N902 is 30%, the O / A ratio is 2:1, the extraction time is 20 min, the extraction rate is 98.2%, and the structure and spatial configuration of naphthalene sulfonic acid can assist N902 to improve the extraction rate of impurities. Then, sodium chloride and a reducing agent are added to the copper sulfate solution after back-extraction. The addition amount of sodium chloride is 1:1 with the copper ions in the solution. The reducing agent sulfur dioxide is added for reduction at 50 °C (the addition amount of sulfur dioxide is 1:1 with the copper ions in the solution). After reacting for 1 h, solid-liquid separation is carried out to obtain cuprous chloride, realizing the recovery and high-value utilization of copper. At this time, the main component in the zinc-containing solution is zinc sulfate, but there are still a small amount of heavy metals such as thallium. Therefore, zinc powder is added to the zinc-containing solution for replacement. The addition amount of zinc powder is 0.1 g / L. The zinc-containing solution after replacement is subjected to zinc electrowinning, and the solid is returned to the first step for dissolution. The composition of the acid-soluble solid is shown in Table 21.

[0098] Table 21 Composition of Acid-Soluble Solid

[0099]

[0100] Leach gold and silver in the acid-soluble solid using a gold leaching agent (which is commercially available). During leaching, ensure that the liquid-solid ratio is 5:1, the leaching time is 24 h, the leaching pH is 10, and the leaching temperature is 25 °C. After the reaction ends, perform solid-liquid separation to obtain a gold-containing solution and a lead-containing solid. The gold-containing solution is extracted with a first organic phase to obtain a gold-rich organic phase and a silver-containing solution. The extractant used for extraction is dibutyl carbitol and sulfonated kerosene. Wash the first organic phase with 0.5 mol / L dilute hydrochloric acid, and reduce gold using a sodium sulfite solution. The ratio of the amount of sodium sulfite added to the gold ions in the solution is 0.5:1. After smelting at 1100 °C, a gold ingot is obtained. Add ammonium ferrous sulfate with a mass fraction of 15% to the silver-containing solution, and then extract it with a second organic phase. The extraction rate is 99.90%. The second organic phase used is diisooctyl sulfide and sulfonated kerosene. Ammonium ferrous sulfate selectively binds with silver ions and synergistically acts with diisooctyl sulfide, effectively improving the extraction rate of silver ions. Then wash the second organic phase with 0.5 mol / L nitric acid, and then back-extract silver using a glucose solution. The ratio of the amount of glucose added to the silver ions in the solution is 1:1. After smelting at 1000 °C, a silver ingot is obtained.

[0101] The composition of the lead-containing solid is shown in Table 22.

[0102] Table 22 Composition of the lead-containing solid

[0103]

[0104] As can be seen from the data in Table 22, the main component of the lead-containing solid is lead sulfate. Dissolve it using a sodium hydroxide solution. The concentration of the sodium hydroxide solution used is 5 mol / L, the liquid-solid ratio is 5:1, the dissolution temperature is maintained at 50 °C, and the dissolution time is 1 h. After the reaction is complete, perform solid-liquid separation to obtain a lead-containing liquid and an alkali-soluble solid. The main component composition of the lead-containing liquid is shown in Table 23:

[0105] Table 23 Composition of the lead-containing solution

[0106]

[0107] As can be seen from the data in Table 23, the main component of the lead-containing solution is lead ions, and the concentration of OH - ions in the solution is very high. To realize the high-value utilization of lead in the lead-containing solution, introduce CO 2 into the lead-containing solution as a precipitant. After stirring and precipitating for 1 h, perform solid-liquid separation to obtain a lead carbonate product. The composition of the alkali-soluble solid is as follows in Table 24:

[0108] Table 24 Composition of the alkali-soluble solid

[0109]

[0110] It can be calculated from the data in Table 24 that the lead dissolution rate is 71.2%. The alkali-soluble solid is dissolved with 2 mol / L sulfuric acid solution. 15 g of ferric chloride is added during the dissolution process. The liquid-solid ratio is maintained at 2:1, and stirring and dissolution are carried out at 50 °C for 3 h. After the dissolution is completed, 5 g / L of lead powder is added for replacement. After replacement at room temperature for 0.5 h, solid-liquid separation is carried out to obtain crude bismuth, and then molten refining is carried out at 600 °C to obtain bismuth ingots.

[0111] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, replacements, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention. The protection scope of the present invention is defined by the claims and their equivalent technical solutions.

Claims

1. A method for recovering nearly all elements in low-noble metal zinc replacement powder, characterized in that The steps include: (1) taking low-noble metal zinc replacement powder, dissolving it in an acid solution, adding an oxidant while dissolving, maintaining the dissolution process at room temperature, dissolving for 1-3 hours, and separating the solid and liquid to obtain a copper-containing solution and an acid-soluble solid; (2) using an extractant to selectively enrich copper in the copper-containing solution obtained in step (1) to obtain a zinc-containing solution and a copper-rich organic phase, and then using a stripping solution for stripping to obtain a copper sulfate solution; adding sodium chloride and a reducing agent to the obtained copper sulfate solution to prepare cuprous chloride, or using it for electrolytic copper deposition to prepare copper powder; adding zinc powder to the zinc-containing solution obtained after extraction for displacement, the amount of zinc powder is 0.1-1g / L, the displacement time is 0.5-1h, and then solid-liquid separation is performed to obtain a zinc sulfate solution and a zinc displacement powder; adding ammonium bicarbonate or ammonium chloride to the zinc sulfate solution to prepare crude zinc hydroxide, and then reducing and roasting to prepare zinc powder, or electrolytic zinc deposition to prepare zinc powder, and the zinc displacement powder is returned to step (1) for recycling; (3) adding a gold extracting agent to the acid-soluble solid obtained in step (1) to leach gold and silver in the acid-soluble solid, ensuring that the liquid-to-solid ratio is 5-10:1 during leaching, the leaching time is 24-48 hours, the leaching pH is 10-14, and the leaching temperature is 25-35° C. After the reaction is completed, the solid-liquid separation is performed to obtain a gold-containing solution and a lead-containing solid; (4) extracting the gold-containing solution obtained in step (3) with the first organic phase, washing the first organic phase with 0.5-1 mol / L dilute hydrochloric acid, stripping the gold with a sodium sulfite solution to obtain a silver-containing solution and sponge gold, and smelting the sponge gold at 1100-1300° C. to obtain a gold ingot; extracting the silver-containing solution with the second organic phase, or adding 10-20% ammonium ferrous sulfate by mass to the silver-containing solution, and then extracting with the second organic phase, and then washing the second organic phase with 0.5-1 mol / L nitric acid, and then stripping with hydrazine hydrate or glucose solution to obtain sponge silver, and smelting the sponge silver at 1000-1200° C. to obtain a silver ingot; (5) dissolving the lead-containing solid obtained in step (3) using an alkaline solution to obtain a lead-containing solution and an alkaline-soluble solid after solid-liquid separation, maintaining the dissolution process at 50-90° C. for 1-3 h; (6) adding a precipitant to the lead-containing solution obtained in step (5) to prepare a lead carbonate product, the reaction time being 1-3 hours; (7) The alkali-soluble solid obtained in step (5) is dissolved using an acid solution, an oxidant is added during the dissolution process, a displacing agent is added after the dissolution is completed, and the displacing agent is used to displace the crude bismuth, which is then smelted at a high temperature of 600-800° C. to prepare a bismuth ingot.

2. The method for recovering nearly all elements in low-noble metal zinc replacement powder according to claim 1, characterized in that: In step (1), the acid solution is sulfuric acid or hydrochloric acid with a concentration of 2-5 mol / L, and the oxidant is sodium peroxide, hydrogen peroxide, calcium hypochlorite or sodium hypochlorite.

3. The method for recovering nearly all elements in low-noble metal zinc replacement powder according to claim 1, characterized in that: In step (2), the extractant is composed of N902 and sulfonated kerosene, the mass concentration of N902 is 20-30%, or the extractant is composed of β-naphthalenesulfonic acid, N902 and sulfonated kerosene, the mass concentration of β-naphthalenesulfonic acid is 1-3%, and the mass concentration of N902 is 20-30%. The stripping solution used is a 1-4 mol / L sulfuric acid solution; the ratio of the amount of sodium chloride added to the amount of copper ions in the copper sulfate solution is 1-2:1, the reducing agent is one or more of sulfur dioxide, sodium sulfite, and copper powder, the ratio of the amount of the reducing agent added to the amount of copper ions in the copper sulfate solution is 1-2:1, the reduction temperature is maintained at 50-90°C, the reduction time is 1-3h, and after the reduction is completed, solid-liquid separation is performed to obtain cuprous chloride solid.

4. The method for recovering nearly all elements in low-noble metal zinc replacement powder according to claim 1, characterized in that: In step (4), the first organic phase is composed of dibutyl carbitol and sulfonated kerosene; and the second organic phase is composed of diisooctyl sulfide and sulfonated kerosene.

5. The method for recovering nearly all elements in low-noble metal zinc replacement powder according to claim 1, characterized in that: In step (5), the alkaline solution is one or more of sodium hydroxide or potassium hydroxide, the concentration of the alkaline solution used is 5-10 mol / L, and the liquid-to-solid ratio is 2-5:

1.

6. The method for recovering nearly all elements in low-noble metal zinc replacement powder according to claim 1, characterized in that: In step (6), the precipitating agent used is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, sodium hydroxide, and carbon dioxide.

7. The method for recovering nearly all elements in low-noble metal zinc replacement powder according to claim 1, characterized in that: In step (7), the acid solution is hydrochloric acid or sulfuric acid, the acid solution concentration is 2-5 mol / L, the liquid-to-solid ratio is 2-5:1, the temperature is 50-80°C, and the dissolution time is 3-5h; the oxidant used is one or more of hydrogen peroxide, ferric chloride, sulfuric acid, and chlorine, and the amount of the oxidant added is 15-30g / L; the displacing agent used is zinc powder, iron powder or lead powder, the amount of the displacing agent added is 5-10g / L, and the displacement time is 0.5-1.5h.

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