Process for comprehensively recovering valuable metals such as nickel, copper, gold, palladium and platinum and sulfur from hot filter residues

Abstract

The invention provides a process for comprehensively recovering valuable metals such as nickel, copper, gold, palladium and platinum and sulfur from hot filter residues, which comprises the following steps of: leaching copper, nickel and iron in the hot filter residues by adopting a high-pressure oxygen leaching process, and respectively recovering iron, copper and nickel in forms of ferric hydroxide, copper sulfide and nickel sulfide by adopting a manner of precipitating iron by adopting sodium hydroxide and precipitating copper and nickel by adopting sodium sulfide in a fractional manner; performing triple-effect crystallization on the generated wastewater to obtain pure sodium sulfate, drying leaching residues generated by high-pressure oxygen leaching, performing hot filtration to obtain crude sulfur and primary noble metal enriched residues, and performing low-pressure distillation on the primary noble metal enriched residues in a vacuum furnace to obtain crude sulfur and secondary noble metal enriched residues; and leaching gold, platinum and palladium in the secondary precious metal enrichment slag by adopting a hydrochloric acid chlorine method, returning the leaching slag to a vacuum distillation process, replacing and enriching precious metals in a leaching solution by adopting zinc powder, and carrying out triple-effect crystallization on generated wastewater after a conventional purification process to obtain a zinc chloride crystal product, so that comprehensive recovery of nickel, copper, gold, palladium, platinum and other valuable metals and sulfur is realized.

Description

Technical Field

[0001] The invention relates to the field of comprehensive recovery of valuable metals, and in particular to a process for comprehensively recovering valuable metals such as nickel, copper, gold, palladium, platinum and sulfur from hot filter residues. Background Art

[0002] During the high-pressure oxygen leaching process of nickel matte, a high-sulfur hot filter residue is produced. In addition to base metals such as nickel and copper, the hot filter residue also contains precious metals such as gold, platinum, and palladium. Although there are many processes for extracting valuable metals from the hot filter residue, most of the processes have the characteristics of incomplete sulfur recovery, high loss rate of precious metals, long recovery cycle, and large amount of wastewater and waste residue discharge, which not only wastes resources but also pollutes the environment. Therefore, the present invention adopts a wet pyrometallurgical method to enrich all the valuable metals such as nickel, copper, gold, palladium, and platinum at low cost, and recovers sulfur in the form of sulfur. No wastewater or waste residue is generated in the whole process, which is of great significance. Summary of the invention

[0003] In view of this, the present invention proposes a process for comprehensively recovering nickel, copper, gold, palladium, platinum and other valuable metals and sulfur from hot filter residues to solve the above problems.

[0004] In view of some problems existing in the prior art, the present invention firstly adopts a high-pressure oxygen leaching process to leach copper, nickel and iron in hot filter residues, adopts sodium hydroxide to precipitate iron, and sodium sulfide to gradedly precipitate copper and nickel to recover iron, copper and nickel in the form of iron hydroxide, copper sulfide and nickel sulfide respectively, and the generated wastewater is crystallized to pure sodium sulfate through three-effect crystallization, and the leached residue generated by the high-pressure oxygen leaching is dried and hot filtered to obtain crude sulfur and primary precious metal enriched residue, and the primary precious metal enriched residue is low-pressure distilled in a vacuum furnace to obtain crude sulfur and secondary precious metal enriched residue, and the hydrochloric acid chlorine method is adopted to leach gold, platinum and palladium in the secondary precious metal enriched residue, and the leached residue is returned to the vacuum distillation process, and the precious metals in the leaching solution are replaced and enriched by zinc powder, and the generated wastewater is subjected to a conventional purification process and then three-effect crystallization to obtain a zinc chloride crystal product.

[0005] The technical solution of the present invention is achieved in this way:

[0006] A process for comprehensively recovering nickel, copper, gold, palladium, platinum and sulfur valuable metals from hot filter residues, comprising the following steps:

[0007] (1) High-pressure oxygen leaching: taking hot filter residue (containing nickel, copper, iron, sulfur, gold, platinum, and palladium); using sulfuric acid, oxygen, and water to perform oxygen pressure leaching on the hot filter residue, and after the reaction is completed, obtaining a leachate (containing copper, nickel, and iron) and a leaching residue (containing gold, platinum, palladium, and sulfur);

[0008] (2) Iron precipitation: adding sodium hydroxide to the leachate from step (1), and filtering after the reaction to obtain a copper-nickel solution and iron hydroxide slag;

[0009] (3) Copper precipitation: adding sodium sulfide to the copper-nickel solution in step (2), and filtering after the reaction to obtain a nickel-containing solution and copper sulfide slag (containing copper and nickel);

[0010] (4) nickel precipitation: adding sodium sulfide to the nickel-containing solution in step (3), filtering after the reaction to obtain a nickel precipitation liquid and nickel sulfide slag, and crystallizing the nickel precipitation liquid to obtain crude sodium sulfate;

[0011] (5) washing: reacting the copper sulfide slag produced in step (3) with the copper-nickel solution prepared in step (2), filtering after the reaction to obtain low-nickel copper sulfide slag (containing copper and nickel) and a washed liquid, and returning the washed liquid to the copper precipitation step;

[0012] (6) Hot filtration: drying the leached residue from step (1), heating it at a constant temperature, and filtering it immediately after the constant temperature is completed to obtain crude sulfur and precious metal primary enrichment residue (containing sulfur, gold, platinum, and palladium);

[0013] (7) Vacuum distillation: placing the precious metal primary enrichment slag in step (6) into a vacuum furnace for vacuum distillation, volatilizing and condensing the sulfur in the precious metal primary enrichment slag to obtain crude sulfur, and vacuum distilling the precious metal primary enrichment slag to obtain precious metal secondary enrichment slag (containing sulfur, gold, platinum, and palladium);

[0014] (8) Precious metal leaching: adding hydrochloric acid and chlorine gas to leach the precious metal secondary enrichment slag in step (7), and obtaining precious metal leaching solution and precious metal leaching slag after the reaction is completed. The precious metal leaching slag is returned to the vacuum distillation step;

[0015] (9) Zinc powder replacement: adding zinc powder to the precious metal leaching solution in step (8), filtering after the reaction to obtain precious metal mud (containing gold, platinum, palladium) and a zinc-containing solution;

[0016] (10) Sulfur preparation: The crude sulfur produced in the hot filtration process and the vacuum distillation process is heated at a constant temperature. After the constant temperature is completed, it is immediately filtered to obtain sulfur and filter residue, and the filter residue is sent to the vacuum distillation process.

[0017] Furthermore, the specific steps of process (1) are as follows: high-pressure oxygen leaching: using sulfuric acid, oxygen and water to carry out oxygen pressure leaching on the hot filter residue, the leaching temperature is 120-150°C, the oxygen pressure is 0.8-1.0MPa, the leaching time is 2-3h, sulfuric acid is added, the amount of sulfuric acid added is 40%-60% of the mass of the precious metal material contained in the hot filter residue, water is added, the liquid-to-solid mass ratio is 3:1-4:1, and after the reaction is completed, a leachate and a leached residue are obtained.

[0018] Furthermore, the specific steps of step (2) are as follows: iron precipitation: adjusting the pH value of the leaching solution of step (1) to 2.5-3.0 with sodium hydroxide, the reaction time is 40-60 minutes, and filtering after the reaction is completed at room temperature to obtain a copper-nickel solution and iron hydroxide slag;

[0019] The specific steps of step (3) are as follows: copper precipitation: adding sodium sulfide nonahydrate to the copper-nickel solution of step (2), controlling the sulfur-copper mass ratio to be 0.62:1-0.72:1, reacting for 40-60 minutes, and filtering after the reaction is completed at room temperature to obtain a nickel-containing solution and copper sulfide slag.

[0020] Furthermore, the specific steps of step (4) are as follows: nickel precipitation: adding sodium sulfide nonahydrate to the nickel-containing solution of step (3), controlling the sulfur-nickel mass ratio to be above 0.6:1, reacting for 40-60 minutes, filtering after the reaction is completed at room temperature to obtain a nickel precipitation liquid and nickel sulfide slag, and the nickel precipitation liquid is crystallized to obtain crude sodium sulfate.

[0021] Furthermore, the specific steps of step (5) are washing: reacting the copper sulfide slag produced in step (3) with the copper-nickel solution prepared according to step (2), controlling the reaction temperature to 85-95°C, controlling the mass of copper in the solution to be ≥2 times the mass of nickel in the copper sulfide slag, reacting for 2.5-3h, filtering to obtain low-nickel copper sulfide slag and washed liquid, and returning the washed liquid to the copper precipitation step.

[0022] Furthermore, the specific steps of step (6) are as follows: hot filtration: after drying the leached residue in step (1), directly put it into a sealed crucible and heat it to 120-130° C., keep the temperature constant for 1-2 hours, and immediately filter it after the constant temperature is completed to obtain the crude sulfur and precious metal enriched slag.

[0023] Furthermore, the specific steps of step (7) are as follows: vacuum distillation: placing the precious metal primary enrichment slag of step (6) into a vacuum furnace for vacuum distillation, first exhausting the air in the vacuum furnace with a vacuum pump, and then introducing nitrogen into the vacuum furnace to ensure that the pressure in the furnace is ≥1.0×10 5 Pa, after stabilizing for 20 minutes, slowly vent, adjust the pressure to 0.1-0.4Pa, control the temperature at 130℃-150℃, control the distillation time at 30-45min, and obtain crude sulfur by volatilization and condensation of sulfur in the primary slag of precious metal enrichment. The primary slag of precious metal is further enriched by vacuum distillation to obtain secondary slag of precious metal enrichment;

[0024] The specific steps of step (8) are as follows: leaching of precious metals: adding hydrochloric acid and chlorine to leach the precious metal secondary enrichment slag of step (7), the leaching temperature is 85°C-95°C, the leaching time is 2-3h, the liquid-to-solid ratio is 4:1-5:1, the chlorine gas introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag, and the chlorine gas introduction rate is 1-20mg / min. After the reaction is completed, precious metal leaching solution and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation step.

[0025] Furthermore, the specific steps of step (9) are as follows: zinc powder replacement: zinc powder is added to the precious metal leachate of step (8), and the amount of zinc powder added is 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate; the reaction is carried out at 45-65°C for 2-3 hours, and then filtered to obtain precious metal mud and zinc-containing solution; the specific steps of step (10) are as follows: sulfur preparation: sulfur produced by the hot filtration step and the vacuum distillation step is directly placed in a sealed crucible and heated to 120°C-130°C, and the temperature is kept constant for 1-2 hours. After the constant temperature is completed, the sulfur and filter residue are immediately filtered to obtain the sulfur and the filter residue, and the filter residue is sent to the vacuum distillation step.

[0026] Furthermore, the present invention comprehensively recovers valuable metals such as nickel, copper, gold, palladium, platinum, etc. from hot filter residues, specifically comprising the following steps:

[0027] (1) High-pressure oxygen leaching: The hot filter residue is subjected to oxygen pressure leaching using sulfuric acid, oxygen and water. The leaching temperature is 120-150°C, the oxygen pressure is 0.8-1.0 MPa, the leaching time is 2-3 hours, sulfuric acid is added, and the amount of sulfuric acid added is 40%-60% of the mass of the precious metal material contained in the hot filter residue. Water is added, and the liquid-solid mass ratio is 3:1-4:1. After the reaction is completed, a leachate and a leached residue are obtained;

[0028] (2) Iron precipitation: adjusting the pH value of the leaching solution in step (1) to 2.5-3.0 with sodium hydroxide, the reaction time is 40-60 min, and after the reaction is completed at room temperature, filtering to obtain a copper-nickel solution and iron hydroxide slag;

[0029] (3) Copper precipitation: adding sodium sulfide nonahydrate to the copper-nickel solution in step (2), controlling the sulfur-copper mass ratio to be 0.62:1-0.72:1, reacting for 40-60 min, and filtering after the reaction is completed at room temperature to obtain a nickel-containing solution and copper sulfide slag;

[0030] (4) nickel precipitation: adding sodium sulfide nonahydrate to the nickel-containing solution in step (3), controlling the sulfur-nickel mass ratio to be greater than 0.6:1, and reacting for 40-60 min. After the reaction is completed at room temperature, filtering is performed to obtain a nickel precipitation liquid and nickel sulfide slag. The nickel precipitation liquid is crystallized to obtain crude sodium sulfate;

[0031] (5) washing: reacting the copper sulfide slag produced in step (3) with the copper-nickel solution prepared in step (2), controlling the reaction temperature to 85-95° C., controlling the mass of copper in the solution to be ≥2 times the mass of nickel in the copper sulfide slag, reacting for 2.5-3 hours, filtering to obtain low-nickel copper sulfide slag and a washed liquid, and returning the washed liquid to the copper precipitation step;

[0032] (6) Hot filtration: After drying the leaching residue from step (1), directly place it in a sealed crucible and heat it to 120-130° C. for 1-2 hours. After the constant temperature is reached, filter it immediately to obtain the crude sulfur and precious metal enriched residue;

[0033] (7) Vacuum distillation: The precious metal primary enrichment slag from step (6) is placed in a vacuum furnace for vacuum distillation. The air in the vacuum furnace is first evacuated using a vacuum pump, and then nitrogen is introduced into the vacuum furnace to ensure that the pressure in the furnace is ≥1.0×10 5 Pa, after stabilizing for 20 minutes, slowly vent, adjust the pressure to 0.1-0.4Pa, control the temperature at 130℃-150℃, control the distillation time at 30-45min, and obtain crude sulfur by volatilization and condensation of sulfur in the primary slag of precious metal enrichment. The primary slag of precious metal is further enriched by vacuum distillation to obtain secondary slag of precious metal enrichment;

[0034] (8) Leaching of precious metals: adding hydrochloric acid and chlorine to leach the precious metal secondary enrichment slag in step (7), the leaching temperature is 85° C.-95° C., the leaching time is 2-3 h, the liquid-to-solid ratio is 4:1-5:1, the chlorine gas introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag, and the chlorine gas introduction rate is 9.67 mg / min. After the reaction is completed, precious metal leaching solution and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation step;

[0035] (9) Zinc powder replacement: adding zinc powder to the precious metal leaching solution of step (8), wherein the amount of zinc powder added is 9-15 times the total amount of gold, platinum and palladium in the precious metal leaching solution, reacting at 45-65° C. for 2-3 hours, and then filtering to obtain precious metal mud and zinc-containing solution;

[0036] (10) Preparation of sulfur: The sulfur produced in the hot filtration process and the vacuum distillation process is directly placed in a sealed crucible and heated to 120°C-130°C for 1-2 hours. After the constant temperature is completed, the sulfur and filter residue are immediately filtered to obtain the sulfur and filter residue, and the filter residue is sent to the vacuum distillation process.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention adopts a high pressure oxygen leaching method to remove the S in the hot filter residue. 2-It is converted into elemental sulfur and precipitated in the slag. At the same time, the sulfate in the hot filtered slag will also enter the solution. At the same time, more than 99% of the sulfur in the leached slag after high-pressure oxygen leaching exists in the form of elemental sulfur, which improves the sulfur recovery rate of the entire system.

[0039] (2) The present invention uses only sulfuric acid and oxygen as leaching agents, which not only allows more than 99% of Cu, Ni, and Fe in the hot filter residue to enter the solution, but also does not use nitrate-containing and chlorine-containing reagents, nor does it use alkaline leaching agents such as sodium hydroxide, sodium sulfide, and ammonia water, ensuring that precious metals such as gold, platinum, and palladium in the hot filter residue do not enter the solution, and more than 99.9% of the precious metals are all retained in the primary enrichment residue of the precious leaching.

[0040] (3) The present invention uses sodium hydroxide to adjust the pH to precipitate iron, and uses sodium sulfide to precipitate copper and nickel in stages. While sodium sulfide is precipitating copper and nickel, a small amount of other heavy metals in the solution will also precipitate. In this way, the heavy metals in the solution after nickel precipitation are purified, and the main component of the solution is sodium sulfate. The sodium sulfate produced after the three-effect crystallization can be used as a raw material for producing industrial sodium sulfate. The high-pressure oxygen leaching system does not produce wastewater and waste residue.

[0041] (4) The present invention utilizes the principle that the solubility products of copper sulfide and nickel sulfide are greatly different, and copper is precipitated first, and then nickel is precipitated. However, when copper is precipitated, part of nickel will be precipitated in the copper sulfide slag. The copper sulfide slag is washed with high-pressure oxygen leaching solution, so that the nickel sulfide in the copper sulfide slag reacts with the copper in the leaching solution and re-enters the solution, which not only improves the recovery rate of nickel in the whole process, but also improves the utilization rate of sulfur in sodium sulfide.

[0042] (5) The present invention adopts a low-cost hot filtration method to separate most of the sulfur in the high-pressure oxygen leaching slag from the precious metals to form sulfur; and adopts a vacuum distillation method to continue to volatilize the sulfur remaining in the precious metals in the hot filtration slag, but controls the distillation time to ensure that the sulfur in the precious metal secondary enrichment slag after distillation is still 30%-40%, so that the precious metals therein are not entrained into the crude sulfur, thereby improving the direct recovery rate of the precious metals.

[0043] (6) The present invention uses hydrochloric acid and chlorine to leach the precious metals in the precious metal secondary enrichment slag, and uses zinc powder to replace the precious metals therein. After repeated cycles, zinc chloride is mainly present in the system, and a zinc chloride crystal product can be obtained after purification. The chlorination leaching system also does not produce wastewater and waste residue. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention is a process flow chart for comprehensively recovering valuable metals such as nickel, copper, gold, palladium, platinum, etc. from hot filter residues. DETAILED DESCRIPTION

[0045] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0046] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0047] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0048] In view of some problems existing in the prior art, the invention firstly adopts a high-pressure oxygen leaching process to leach copper, nickel and iron in hot filter residues, adopts sodium hydroxide to precipitate iron, and sodium sulfide to gradedly precipitate copper and nickel to recover iron, copper and nickel in the form of iron hydroxide, copper sulfide and nickel sulfide respectively, generates wastewater through three-effect crystallization to pure sodium sulfate, leached residue generated by high-pressure oxygen leaching is dried, and then hot filtered at normal pressure at a certain temperature to obtain crude sulfur and primary precious metal enriched residue, the primary precious metal enriched residue is low-pressure distilled in a vacuum furnace to obtain crude sulfur and secondary precious metal enriched residue, hydrochloric acid chlorine method is adopted to leach gold, platinum and palladium in the secondary precious metal enriched residue, the leached residue is returned to the vacuum distillation process, zinc powder is used to replace and enrich the precious metals in the leaching solution, and the generated wastewater is subjected to a conventional purification process and then three-effect crystallization to obtain a pure zinc chloride crystal product, and no wastewater or waste residue is generated in the whole process.

[0049] The process flow of this method is as follows:

[0050] 2CuS+2H2SO4+O2═CuSO4+2S↓+2H2O

[0051] 2NiS+2H2SO4+O2═2NiSO4+2S↓+2H2O

[0052] NiS+CuSO4═NiSO4+CuS↓

[0053] 2Au+3Cl2+2HCl=2HAuCl4

[0054] The implementation steps of the present invention are as follows:

[0055] (1) High-pressure oxygen leaching: The hot filter residue is subjected to oxygen pressure leaching using sulfuric acid + oxygen + water. The leaching temperature is 120-150°C, the oxygen pressure is 0.8MPa-1.0MPa, the leaching time is 2-3h, the liquid-solid ratio (mass) is 3:1-4:1, and the amount of sulfuric acid added is 40%-60% of the mass of the precious metal-containing material. After the reaction is completed, a leachate and leaching residue are obtained.

[0056] (2) Iron precipitation: Use sodium hydroxide to adjust the pH of the leachate to 2.5-3.0, the reaction time is 40min-60min, and after the reaction is completed at room temperature, filter to obtain a copper-nickel solution and iron hydroxide slag

[0057] (3) Copper precipitation: The sulfur-copper mass ratio is controlled to be 0.62:1-0.72:1, and the reaction time is 40 min-60 min. After the reaction is completed at room temperature, the nickel-containing solution and copper sulfide slag are obtained by filtration.

[0058] (4) Nickel precipitation: The sulfur-nickel mass ratio is controlled to be above 0.6:1, and the reaction time is 40 min-60 min. After the reaction is completed at room temperature, the nickel precipitation liquid and nickel sulfide slag are obtained by filtration. The nickel sulfide slag is sent to nickel smelting. The nickel precipitation liquid is subjected to three-effect crystallization to obtain crude sodium sulfate, which can be used as a raw material for the preparation of sodium sulfate products.

[0059] (5) Washing: react the copper-nickel solution with copper sulfide slag, control the reaction temperature to 85°C-95°C, and control the mass of copper in the solution to be greater than or equal to twice the mass of nickel in the copper sulfide slag. After reacting for 2.5-3 hours, filter to obtain low-nickel copper sulfide slag and washed liquid. The washed liquid is returned to the copper precipitation process, and the low-nickel copper sulfide slag is sent to the copper smelting process.

[0060] (6) Hot filtration: After drying the leached residue, directly place it in a sealed crucible and heat it to 120°C-130°C for 1h-2h. After the constant temperature is completed, filter it immediately to obtain the crude sulfur and precious metal enriched slag.

[0061] (7) Vacuum distillation: Place the precious metal primary enriched slag in a vacuum furnace for vacuum distillation. First, use a vacuum pump to evacuate the air in the vacuum furnace, then introduce nitrogen into the vacuum furnace to ensure that the pressure in the furnace is greater than or equal to 10 5 Pa, after stabilizing for 20 minutes, slowly vent and adjust the pressure to 0.1-0.4Pa, control the temperature at 130℃-150℃, control the distillation time at 30-45min, and obtain crude sulfur after volatilization and condensation of sulfur in the primary enrichment slag of precious metals. The primary enrichment slag of precious metals is further enriched after vacuum distillation to obtain secondary enrichment slag of precious metals.

[0062] (8) Precious metal leaching: Pure hydrochloric acid + chlorine gas is used to leach the precious metal secondary enrichment slag. The leaching temperature is 85°C-95°C, the leaching time is 2-3 hours, the liquid-to-solid ratio is 4:1-5:1, and the chlorine gas introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag. The chlorine gas addition rate is controlled according to the reaction time and the amount of chlorine gas added. After the reaction is completed, precious metal leaching solution and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation process.

[0063] (9) Zinc powder replacement: zinc powder is added to the precious metal leachate, the amount of zinc powder added is 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate, and the reaction is carried out at 45-65°C for 2-3 hours, and then filtered to obtain precious metal mud and zinc-containing solution. The precious metal mud is sent to the precious metal purification process to extract gold, platinum and palladium, and the zinc-containing solution is recycled for the precious metal leaching process. When the zinc concentration in the circulating zinc-containing solution is greater than or equal to 100g / L, it is sent to the three-effect crystallization process to recover the zinc chloride product.

[0064] (10) Sulfur preparation: The sulfur produced in the hot filtration process and the vacuum distillation process is directly placed in a sealed crucible and heated to 120°C-130°C for 1h-2h. After the constant temperature is achieved, the sulfur is immediately filtered to obtain the hot filtration residue from the sulfur preparation process and sent to the vacuum distillation process.

[0065] Example 1

[0066] Raw materials: Take 100g of hot filter residue, which contains 11.32% nickel, 15.38% copper, 7.16% iron, 50.55% sulfur, 96.53g / t gold, 110.61g / t platinum and 89.15g / t palladium.

[0067] (1) High-pressure oxygen leaching: The hot filter residue was subjected to oxygen pressure leaching using sulfuric acid + oxygen + water. The leaching temperature was 120°C, the oxygen pressure was 0.8 MPa, the leaching time was 2.5 h, 27 mL of sulfuric acid and 300 mL of water were added, and after the reaction, 312 mL of leachate and 60.32 g of leachate residue were obtained. The leachate contained 48.8 g / L of copper, 35.91 g / L of nickel, and 22.71 g / L of iron. The leachate contained 160.02 g / t of gold, 183.37 g / t of platinum, 147.79 g / t of palladium, and 83.02% of sulfur.

[0068] (2) Iron precipitation: The pH value of the leaching solution in step (1) was adjusted to 2.5 using sodium hydroxide. The reaction time was 40 min. After the reaction was completed at room temperature, the copper-nickel solution and 16.32 g of iron hydroxide slag were obtained by filtration. The iron content in the iron hydroxide slag was 41.81%.

[0069] (3) Copper precipitation: 77.65 g of sodium sulfide nonahydrate was added to the copper-nickel solution (liquid after iron precipitation) in step (2), and the reaction time was 40 min. After the reaction was completed at room temperature, 305 mL of nickel-containing solution was obtained by filtration, wherein the nickel content was 28.27 g / L; 31.25 g of copper sulfide slag was obtained, wherein the copper content was 48.23% and the nickel content was 8.26%.

[0070] (4) Nickel precipitation: 45.26 g of sodium sulfide nonahydrate was added to the nickel-containing solution in step (3), and the reaction time was 60 min. After the reaction was completed at room temperature, the solution was filtered to obtain a nickel precipitation solution containing 0.008 g / L nickel. 16.20 g of nickel sulfide slag was obtained, containing 53.20% nickel. The nickel precipitation solution was subjected to triple crystallization to obtain crude sodium sulfate, which can be used as a raw material for the preparation of sodium sulfate products.

[0071] (5) Washing: The copper sulfide slag from step (3) is reacted with 200 mL of a copper-nickel solution (a copper-nickel solution prepared according to the conditions of step (2)), the reaction temperature is controlled at 95° C., and after reacting for 3 h, 36.25 g of a low-nickel copper sulfide slag and a washed liquid are obtained by filtration. The low-nickel copper sulfide slag contains 51.26% copper and 0.53% nickel. The washed liquid is returned to the copper precipitation step.

[0072] (6) Hot filtration: After drying the leaching residue from step (1), directly place it in a sealed crucible and heat it to 130° C. for 1.5 h. After the constant temperature is reached, filter it immediately to obtain 45.50 g of crude sulfur, which contains 91.25% sulfur. 12.31 g of precious metal primary enrichment slag is obtained, which contains 73.28% sulfur, 784.11 g / t gold, 898.52 g / t platinum, and 724.18 g / t palladium.

[0073] (7) Vacuum distillation: The precious metal primary enrichment slag from step (6) is placed in a vacuum furnace for vacuum distillation. The air in the vacuum furnace is first evacuated using a vacuum pump, and then nitrogen is introduced into the vacuum furnace to ensure that the pressure in the furnace is 1.5×10 5 Pa, after stabilizing for 20 minutes, slowly vent, adjust the pressure to 0.2Pa, control the temperature at 135℃, control the distillation time for 35 minutes, and obtain 8.32g of crude sulfur, of which the sulfur content is 95.22%, and obtain 3.11g of precious metal secondary enrichment slag, of which the sulfur content is 35.26%, gold 3103.66g / t, platinum 3556.52g / t, and palladium 2866.44g / t.

[0074] (8) Precious metal leaching: 13 mL of hydrochloric acid + 1.2 g of chlorine gas was added to leach the precious metal secondary enrichment slag in step (7). The leaching temperature was 85° C., the leaching time was 3 h, and the chlorine gas introduction rate was 6.67 mg / min. After the reaction was completed, precious metal leaching solution and precious metal leaching slag were obtained. The precious metal leaching slag was returned to the vacuum distillation step.

[0075] (9) Zinc powder replacement: Add 2.96 g of zinc powder to the precious metal leaching solution in step (8), react at 45°C for 3 hours, and then filter to obtain 0.96 g of precious metal mud and a zinc-containing solution. The precious metal mud contains 10047.56 g / t of gold, 11511.64 g / t of platinum, and 9279.07 g / t of palladium. The direct recovery rates of gold, platinum, and palladium are 99.92%, 99.91%, and 99.92%.

[0076] (10) Preparation of sulfur: 53.82 g of sulfur produced in the hot filtration and vacuum distillation steps was directly placed in a sealed crucible and heated to 125° C. for 1 h. After the constant temperature was achieved, 39.90 g of sulfur was immediately filtered to obtain a sulfur content of 99.12%.

[0077] Example 2

[0078] Raw materials: Take 100g of hot filter residue, which contains 6.21% nickel, 7.12% copper, 4.11% iron, 60.26% sulfur, 42.56g / t gold, 30.28g / t platinum and 35.12g / t palladium.

[0079] (1) High-pressure oxygen leaching: The hot filter residue was subjected to oxygen pressure leaching using sulfuric acid + oxygen + water. The leaching temperature was 130°C, the oxygen pressure was 0.8 MPa, the leaching time was 3 h, 24 mL of sulfuric acid and 300 mL of water were added, and after the reaction, 315 mL of leachate and 72.32 g of leachate residue were obtained. The leachate contained 22.37 g / L of copper, 19.51 g / L of nickel, and 12.91 g / L of iron. The leachate contained 58.84 g / t of gold, 41.86 g / t of platinum, 48.56 g / t of palladium, and 83.32% of sulfur.

[0080] (2) Iron precipitation: The pH of the leaching solution in step (1) was adjusted to 2.5 using sodium hydroxide. The reaction time was 60 min. After the reaction was completed at room temperature, the copper-nickel solution and 10.03 g of iron hydroxide slag were obtained by filtration. The iron hydroxide slag contained 40.13% iron.

[0081] (3) Copper precipitation: 34.53 g of sodium sulfide nonahydrate was added to the copper-nickel solution in step (2) and the reaction time was 50 min. After the reaction was completed at room temperature, 302 mL of nickel-containing solution was obtained by filtration, wherein the nickel content was 17.62 g / L; and 13.48 g of copper sulfide slag was obtained, wherein the copper content was 45.12% and the nickel content was 6.11%.

[0082] (4) Nickel precipitation: 26.73 g of sodium sulfide nonahydrate was added to the nickel-containing solution in step (3), and the reaction time was 60 min. After the reaction was completed at room temperature, the solution was filtered to obtain a nickel precipitation solution containing 0.005 g / L nickel. 10.38 g of nickel sulfide slag was obtained, containing 51.25% nickel. The nickel precipitation solution was subjected to triple crystallization to obtain crude sodium sulfate, which can be used as a raw material for the preparation of sodium sulfate products.

[0083] (5) Washing: The copper sulfide slag produced in step (3) is reacted with 150 mL of a copper-nickel solution (a copper-nickel solution prepared according to the conditions of step (2)), the reaction temperature is controlled at 95° C., and after reacting for 3 h, 11.23 g of a low-nickel copper sulfide slag and a washed liquid are obtained by filtering. The low-nickel copper sulfide slag contains 50.11% copper and 0.51% nickel. The washed liquid is returned to the copper precipitation step.

[0084] (6) Hot filtration: After drying the leaching residue from step (1), directly place it in a sealed crucible and heat it to 125° C. for 2 h. After the constant temperature is reached, filter it immediately to obtain 50.13 g of crude sulfur, which contains 93.16% sulfur. 18.53 g of precious metal primary enrichment slag is obtained, which contains 73.16% sulfur, 229.64 g / t gold, 163.37 g / t platinum, and 189.52 g / t palladium.

[0085] (7) Vacuum distillation: The precious metal primary enrichment slag from step (6) is placed in a vacuum furnace for vacuum distillation. The air in the vacuum furnace is first evacuated using a vacuum pump, and then nitrogen is introduced into the vacuum furnace to ensure that the pressure in the furnace is 1.2×10 5 Pa, after stabilizing for 20 minutes, slowly vent, adjust the pressure to 0.25Pa, control the temperature at 140℃, control the distillation time for 40 minutes, and obtain 12.86g of crude sulfur, of which the sulfur content is 96.15%, and obtain 3.33g of precious metal secondary enrichment slag, of which the sulfur content is 38.12%, gold is 1277.84g / t, platinum is 909.08g / t, and palladium is 1054.59g / t.

[0086] (8) Precious metal leaching: 15 mL of hydrochloric acid + 1.16 g of chlorine gas was added to leach the precious metal secondary enrichment slag in step (7). The leaching temperature was 95° C., the leaching time was 2 h, and the chlorine gas introduction rate was 9.67 mg / min. After the reaction was completed, precious metal leaching solution and precious metal leaching slag were obtained. The precious metal leaching slag was returned to the vacuum distillation step.

[0087] (9) Zinc powder replacement: 1.4 g of zinc powder was added to the precious metal leaching solution in step (8), and the mixture was reacted at 45°C for 2 h. After that, the mixture was filtered to obtain 0.55 g of precious metal mud and a zinc-containing solution. The precious metal mud contained 7730.74 g / t of gold, 5500.06 g / t of platinum, and 6380.06 g / t of palladium. The direct recovery rates of gold, platinum, and palladium were 99.90%, 99.90%, and 99.91%, respectively.

[0088] (10) Preparation of sulfur: 62.99 g of sulfur produced in the hot filtration and vacuum distillation steps was directly placed in a sealed crucible and heated to 125° C. for 1 hour. After the constant temperature was achieved, 47.18 g of sulfur was immediately filtered to obtain a sulfur content of 99.32%.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for comprehensively recovering nickel, copper, gold, palladium, platinum and sulfur valuable metals from hot filter residues, characterized in that: The following steps are involved: (1) High-pressure oxygen leaching: The hot filter residue is subjected to oxygen pressure leaching using sulfuric acid, oxygen and water, and a leachate and leaching residue are obtained after the reaction is completed; (2) Iron precipitation: adding sodium hydroxide to the leachate from step (1), and filtering after the reaction to obtain a copper-nickel solution and iron hydroxide slag; (3) Copper precipitation: adding sodium sulfide to the copper-nickel solution in step (2), and filtering after the reaction to obtain a nickel-containing solution and copper sulfide slag; (4) nickel precipitation: adding sodium sulfide to the nickel-containing solution in step (3), filtering after the reaction to obtain a nickel precipitation liquid and nickel sulfide slag, and crystallizing the nickel precipitation liquid to obtain crude sodium sulfate; (5) washing: reacting the copper sulfide slag produced in step (3) with the copper-nickel solution prepared in step (2), filtering after the reaction to obtain low-nickel copper sulfide slag and a washed liquid, and returning the washed liquid to the copper precipitation step; (6) Hot filtration: drying the leaching residue from step (1), heating it at a constant temperature, and filtering it immediately after the constant temperature is completed to obtain a primary enrichment residue of crude sulfur and precious metals; (7) Vacuum distillation: placing the precious metal primary enrichment slag in step (6) into a vacuum furnace for vacuum distillation, volatilizing and condensing sulfur in the precious metal primary enrichment slag to obtain crude sulfur, and vacuum distilling the precious metal primary enrichment slag to obtain precious metal secondary enrichment slag; (8) Precious metal leaching: adding hydrochloric acid and chlorine gas to leach the precious metal secondary enrichment slag in step (7), and obtaining precious metal leaching solution and precious metal leaching slag after the reaction is completed. The precious metal leaching slag is returned to the vacuum distillation step; (9) Zinc powder replacement: adding zinc powder to the precious metal leaching solution in step (8), filtering after the reaction to obtain precious metal mud and zinc-containing solution; (10) Sulfur preparation: The crude sulfur produced in the hot filtration process and the vacuum distillation process is heated at a constant temperature. After the constant temperature is completed, it is immediately filtered to obtain sulfur and filter residue, and the filter residue is sent to the vacuum distillation process.

2. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of process (1) are as follows: high-pressure oxygen leaching: using sulfuric acid, oxygen and water to carry out oxygen pressure leaching on the hot filter residue, the leaching temperature is 120-150°C, the oxygen pressure is 0.8-1.0MPa, the leaching time is 2-3h, sulfuric acid is added, and the amount of sulfuric acid added is 40%-60% of the mass of the precious metal material contained in the hot filter residue, water is added, and the liquid-to-solid mass ratio is 3:1-4:

1. After the reaction is completed, a leachate and a leached residue are obtained.

3. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum valuable metals and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of step (2) are as follows: iron precipitation: adjusting the pH value of the leaching solution of step (1) to 2.5-3.0 with sodium hydroxide, reacting for 40-60 minutes, and filtering after the reaction is completed at room temperature to obtain a copper-nickel solution and iron hydroxide slag; The specific steps of step (3) are as follows: copper precipitation: adding sodium sulfide nonahydrate to the copper-nickel solution of step (2), controlling the sulfur-copper mass ratio to be 0.62:1-0.72:1, reacting for 40-60 minutes, and filtering after the reaction is completed at room temperature to obtain a nickel-containing solution and copper sulfide slag.

4. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum valuable metals and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of step (4) are as follows: nickel precipitation: adding sodium sulfide nonahydrate to the nickel-containing solution of step (3), controlling the sulfur-nickel mass ratio to be above 0.6:1, reacting for 40-60 minutes, filtering after the reaction is completed at room temperature to obtain a nickel precipitation liquid and nickel sulfide slag, and the nickel precipitation liquid is crystallized to obtain crude sodium sulfate.

5. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum valuable metals and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of step (5) are as follows: washing: reacting the copper sulfide slag produced in step (3) with the copper-nickel solution prepared according to step (2), controlling the reaction temperature to 85-95°C, controlling the mass of copper in the solution to be ≥2 times the mass of nickel in the copper sulfide slag, reacting for 2.5-3h, filtering to obtain low-nickel copper sulfide slag and washed liquid, and returning the washed liquid to the copper precipitation step.

6. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum valuable metals and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of step (6) are as follows: hot filtration: after drying the leached residue in step (1), directly put it into a sealed crucible and heat it to 120-130° C., keep the temperature constant for 1-2 hours, and immediately filter it after the constant temperature is completed to obtain the crude sulfur and precious metal primary enriched slag.

7. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum valuable metals and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of step (7) are as follows: vacuum distillation: the precious metal primary enrichment slag of step (6) is placed in a vacuum furnace for vacuum distillation, the air in the vacuum furnace is first evacuated by a vacuum pump, and nitrogen is then introduced into the vacuum furnace to ensure that the pressure in the furnace is ≥1.0×10 5 Pa, after stabilization for 20 minutes, slowly vent, adjust the pressure to 0.1-0.4 Pa, control the temperature at 130°C-150°C, control the distillation time at 30-45 minutes, and obtain crude sulfur after volatilization and condensation of sulfur in the precious metal primary enrichment slag. The precious metal primary slag is further enriched after vacuum distillation to obtain precious metal secondary enrichment slag. The specific steps of step (8) are as follows: precious metal leaching: adding hydrochloric acid and chlorine to leach the precious metal secondary enrichment slag in step (7), the leaching temperature is 85°C-95°C, the leaching time is 2-3h, the liquid-solid ratio is 4:1-5:1, and the chlorine gas introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag. After the reaction is completed, precious metal leaching solution and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation step.

8. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residues according to claim 1, characterized in that: The specific steps of step (9) are as follows: zinc powder replacement: zinc powder is added to the precious metal leachate of step (8), and the amount of zinc powder added is 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate; the reaction is carried out at 45-65° C. for 2-3 hours, and then filtered to obtain precious metal mud and zinc-containing solution; the specific steps of step (10) are as follows: sulfur preparation: sulfur produced in the hot filtration step and the vacuum distillation step is directly placed in a sealed crucible and heated to 120° C.-130° C., and the temperature is kept constant for 1-2 hours. After the constant temperature is completed, the sulfur and filter residue are immediately filtered to obtain the sulfur and the filter residue, and the filter residue is sent to the vacuum distillation step.

9. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residues according to claim 1, characterized in that: The following steps are involved: (1) High-pressure oxygen leaching: The hot filter residue is subjected to oxygen pressure leaching using sulfuric acid, oxygen and water. The leaching temperature is 120-150°C, the oxygen pressure is 0.8-1.0 MPa, the leaching time is 2-3 hours, sulfuric acid is added, and the amount of sulfuric acid added is 40%-60% of the mass of the precious metal material contained in the hot filter residue. Water is added, and the liquid-solid mass ratio is 3:1-4:

1. After the reaction is completed, a leachate and a leached residue are obtained; (2) Iron precipitation: adjusting the pH value of the leaching solution in step (1) to 2.5-3.0 with sodium hydroxide, the reaction time is 40-60 min, and after the reaction is completed at room temperature, filtering to obtain a copper-nickel solution and iron hydroxide slag; (3) Copper precipitation: adding sodium sulfide nonahydrate to the copper-nickel solution in step (2), controlling the sulfur-copper mass ratio to be 0.62:1-0.72:1, reacting for 40-60 min, and filtering after the reaction is completed at room temperature to obtain a nickel-containing solution and copper sulfide slag; (4) nickel precipitation: adding sodium sulfide nonahydrate to the nickel-containing solution in step (3), controlling the sulfur-nickel mass ratio to be greater than 0.6:1, and reacting for 40-60 min. After the reaction is completed at room temperature, filtering is performed to obtain a nickel precipitation liquid and nickel sulfide slag. The nickel precipitation liquid is crystallized to obtain crude sodium sulfate; (5) washing: reacting the copper sulfide slag produced in step (3) with the copper-nickel solution prepared in step (2), controlling the reaction temperature to 85-95° C., controlling the mass of copper in the solution to be ≥2 times the mass of nickel in the copper sulfide slag, reacting for 2.5-3 hours, filtering to obtain low-nickel copper sulfide slag and a washed liquid, and returning the washed liquid to the copper precipitation step; (6) Hot filtration: After drying the leaching residue from step (1), directly place it in a sealed crucible and heat it to 120-130° C. for 1-2 hours. After the constant temperature is reached, filter it immediately to obtain the crude sulfur and precious metal enriched residue; (7) Vacuum distillation: The precious metal primary enrichment slag from step (6) is placed in a vacuum furnace for vacuum distillation. The air in the vacuum furnace is first evacuated using a vacuum pump, and then nitrogen is introduced into the vacuum furnace to ensure that the pressure in the furnace is ≥1.0×10 5 Pa, after stabilizing for 20 minutes, slowly vent, adjust the pressure to 0.1-0.4Pa, control the temperature at 130℃-150℃, control the distillation time at 30-45min, and obtain crude sulfur by volatilization and condensation of sulfur in the primary slag of precious metal enrichment. The primary slag of precious metal is further enriched by vacuum distillation to obtain secondary slag of precious metal enrichment; (8) Leaching of precious metals: adding hydrochloric acid and chlorine to leach the precious metal secondary enrichment slag in step (7), the leaching temperature is 85° C.-95° C., the leaching time is 2-3 h, the liquid-to-solid ratio is 4:1-5:1, the chlorine gas introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag, and the chlorine gas introduction rate is 9.67 mg / min. After the reaction is completed, precious metal leaching solution and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation step; (9) Zinc powder replacement: adding zinc powder to the precious metal leaching solution of step (8), wherein the amount of zinc powder added is 9-15 times the total amount of gold, platinum and palladium in the precious metal leaching solution, reacting at 45-65° C. for 2-3 hours, and then filtering to obtain precious metal mud and zinc-containing solution; (10) Preparation of sulfur: The sulfur produced in the hot filtration process and the vacuum distillation process is directly placed in a sealed crucible and heated to 120°C-130°C for 1-2 hours. After the constant temperature is completed, the sulfur and filter residue are immediately filtered to obtain the sulfur and filter residue, and the filter residue is sent to the vacuum distillation process.

10. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residues according to any one of claims 1 to 9, characterized in that: The hot filter residue contains nickel, copper, iron, sulfur, gold, platinum and palladium.

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