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

Abstract

The invention provides a process for comprehensively recovering nickel, copper, gold, palladium, platinum and other valuable metals and sulfur from hot filter residue. The process comprises the following steps: a high-pressure oxygen leaching process is adopted to leach copper, nickel and iron from the hot filter residue; iron is precipitated by sodium hydroxide and copper and nickel are graded with sodium sulfide to recover the iron, copper and nickel in the form of iron hydroxide, copper sulfide and nickel sulfide respectively; waste water generated is subjected to three-effect crystallization to pure sodium sulfate; leached residue generated by the high-pressure oxygen leaching is dried and hot filtered to obtain crude sulfur and a primary precious metal enrichment residue; the primary precious metal enrichment residue is subjected to low-pressure distillation in a vacuum furnace to obtain crude sulfur and a secondary precious metal enrichment residue; gold, platinum and palladium in the secondary precious metal enrichment residue are leached by a hydrochloric acid chlorine method; the leached residue is returned to a vacuum distillation process; zinc powder is used to replace and enrich the precious metals in the leachate; the waste water generated is subjected to a conventional purification process and then subjected to three-effect crystallization to obtain a zinc chloride crystal product, thereby achieving comprehensive recovery of nickel, copper, gold, palladium, platinum and other valuable metals and sulfur.

Description

Technical Field

[0001] The present 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. This hot filter residue contains not only base metals such as nickel and copper, but also precious metals such as gold, platinum, and palladium. Although there are many processes for extracting valuable metals from hot filter residue, most of these processes suffer from incomplete sulfur recovery, high precious metal loss rates, long recovery cycles, and high wastewater and waste residue emissions, resulting in not only a waste of resources but also environmental pollution. Therefore, the present invention utilizes a wet pyrolysis method to fully enrich the valuable metals such as nickel, copper, gold, palladium, and platinum at low cost, and recover the sulfur as sulfur. The entire process generates no wastewater or waste residue, 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 residue to solve the above problems.

[0004] In view of some problems existing in the prior art, the present invention first adopts a high-pressure oxygen leaching process to leach copper, nickel and iron from hot filter residues, adopts sodium hydroxide to precipitate iron, and sodium sulfide to gradedly precipitate copper and nickel, so as to recover iron, copper and nickel in the form of iron hydroxide, copper sulfide and nickel sulfide respectively, and the generated wastewater is subjected to triple-effect crystallization to pure sodium sulfate, 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 gold, platinum and palladium in the secondary precious metal enriched residue are leached by a hydrochloric acid chlorine method, and the leached residue is returned to the vacuum distillation process, and the precious metals in the leachate are replaced and enriched by zinc powder, and the generated wastewater is subjected to a conventional purification process and triple-effect crystallization to obtain a zinc chloride crystal product.

[0005] The technical solution of the present invention is achieved as follows:

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

[0007] (1) High-pressure oxygen leaching: Take hot filter residue (containing nickel, copper, iron, sulfur, gold, platinum, and palladium); use sulfuric acid, oxygen, and water to leach the hot filter residue under oxygen pressure, and after the reaction is completed, obtain leachate (containing copper, nickel, and iron) and 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: sodium sulfide is added to the nickel-containing solution in step (3), and after the reaction is completed, the nickel precipitation liquid and nickel sulfide residue are obtained by filtration, and the nickel precipitation liquid is crystallized 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 leaching 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 from 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 slag to obtain precious metal secondary enrichment slag (containing sulfur, gold, platinum, and palladium);

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

[0015] (9) Zinc powder replacement: zinc powder is added to the precious metal leaching solution in step (8), and after the reaction, the precious metal mud (containing gold, platinum, palladium) and the zinc-containing solution are obtained by filtration;

[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 step (1) are as follows: high-pressure oxygen leaching: using sulfuric acid, oxygen and water to perform 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% to 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 to 4:1. After the reaction is completed, a leachate and a leaching residue are obtained.

[0018] Furthermore, the specific steps of step (2) are as follows: iron precipitation: adjusting the pH value of the leachate in 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;

[0019] The specific steps of step (3) are as follows: 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 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 nickel precipitation liquid and nickel sulfide slag, and obtaining crude sodium sulfate after crystallization of the nickel precipitation liquid.

[0021] Furthermore, 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 2.5-3 hours, 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 leaching 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 from step (6) into a vacuum furnace for vacuum distillation, first evacuating 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, stabilize for 20 minutes, then slowly vent, adjust the pressure to 0.1-0.4 Pa, control the temperature at 130-150°C, control the distillation time at 30-45 minutes, and volatilize and condense the sulfur in the precious metal primary enrichment slag to obtain crude sulfur. The precious metal primary slag is further enriched by vacuum distillation to obtain precious metal secondary enrichment slag;

[0024] The specific steps of step (8) are as follows: precious metal leaching: hydrochloric acid and chlorine are added to leach the precious metal secondary enrichment slag of step (7), the leaching temperature is 85°C-95°C, the leaching time is 2-3 hours, the liquid-solid ratio is 4:1-5:1, the chlorine introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag, and the chlorine introduction rate is 1-20 mg / min. After the reaction is completed, precious metal leachate 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: adding zinc powder to the precious metal leachate 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 leachate, reacting at 45-65°C for 2-3 hours, and then filtering to obtain precious metal mud and zinc-containing solution; the specific steps of step (10) are as follows: sulfur preparation: directly placing the sulfur produced in the hot filtration step and the vacuum distillation step into a sealed crucible, heating it to 120°C-130°C, and maintaining the temperature for 1-2 hours. After the temperature is maintained, filtering is immediately performed to obtain sulfur and 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, and platinum from hot filter residue, 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, and the leaching time is 2-3 hours. Sulfuric acid is added in an amount of 40% to 60% of the mass of the precious metal material in the hot filter residue. Water is added at a liquid-solid mass ratio of 3:1 to 4:1. After the reaction is completed, a leachate and leaching residue are obtained.

[0028] (2) Iron precipitation: using sodium hydroxide to adjust the pH value of the leachate from step (1) to 2.5-3.0, the reaction time is 40-60 min, and after the reaction is completed at room temperature, filtering is performed 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, and reacting for 40-60 min. After the reaction is completed at room temperature, filtering is performed 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 above 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 h, filtering to obtain low-nickel copper sulfide slag and a washed solution, and returning the washed solution 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, 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 enrichment residue;

[0033] (7) Vacuum distillation: Place the precious metal primary enrichment slag from step (6) into 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 ≥1.0×10 5 Pa, stabilize for 20 minutes, then slowly vent, adjust the pressure to 0.1-0.4 Pa, control the temperature at 130-150°C, control the distillation time at 30-45 minutes, and volatilize and condense the sulfur in the precious metal primary enrichment slag to obtain crude sulfur. The precious metal primary slag is further enriched by vacuum distillation to obtain precious metal secondary enrichment slag;

[0034] (8) Precious metal leaching: hydrochloric acid and chlorine are added 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 hours, the liquid-solid ratio is 4:1-5:1, the chlorine introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag, and the chlorine introduction rate is 9.67 mg / min. After the reaction is completed, precious metal leachate 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: Add zinc powder to the precious metal leachate in step (8), the amount of zinc powder added being 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate, react at 45-65°C for 2-3h, and then filter 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, and kept at this temperature for 1-2 hours. After the constant temperature is achieved, 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 the method of high pressure oxygen leaching 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, sulfate in the hot filter residue will also enter the solution. At the same time, more than 99% of the sulfur in the leached residue after high-pressure oxygen leaching exists in the form of elemental sulfur, thereby improving 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- 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 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 precipitates 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 triple-effect crystallization can be used as a raw material for producing industrial sodium sulfate. The high-pressure oxygen leaching system does not produce wastewater or waste residue.

[0041] (4) The present invention utilizes the principle that the solubility products of copper sulfide and nickel sulfide differ significantly, precipitating copper first and then nickel. However, when copper is precipitated, some nickel will precipitate in the copper sulfide slag. The copper sulfide slag is washed with a high-pressure oxygen leaching solution, causing the nickel sulfide in the copper sulfide slag to react with the copper in the leaching solution and re-enter the solution. This not only improves the nickel recovery rate of the entire process, but also improves the utilization rate of sulfur in the 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 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, the system is mainly composed of zinc chloride, and after purification, a zinc chloride crystal product can be obtained. 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 examples are provided below to further illustrate the present invention.

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

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

[0048] In view of some problems existing in the prior art, the present invention first adopts a high-pressure oxygen leaching process to leach copper, nickel and iron from hot filter residues, adopts sodium hydroxide to precipitate iron, and sodium sulfide to gradedly precipitate copper and nickel, so as 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 then hot-filtered at a certain temperature and normal pressure 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 gold, platinum and palladium in the secondary precious metal enriched residue are leached through a hydrochloric acid chlorine method, and the leached residue is returned to the vacuum distillation process, and the precious metals therein are replaced and enriched by zinc powder in the leachate, and the generated wastewater is subjected to a conventional purification process and then crystallized through three-effect crystallization to obtain a pure zinc chloride crystalline product, and the whole process does not generate wastewater or waste residue.

[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 present invention implements the steps 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: Control the sulfur-copper mass ratio to be 0.62:1-0.72:1, and the reaction time to be 40 min-60 min. After the reaction is completed at room temperature, filter to obtain a nickel-containing solution and copper sulfide slag.

[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 filtered to obtain the nickel precipitation liquid. 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: reacting the copper-nickel solution with copper sulfide slag, controlling the reaction temperature to 85°C-95°C, and controlling the mass of copper in the solution to be greater than or equal to 2 times the mass of nickel in the copper sulfide slag. After reacting for 2.5-3 hours, filtering is performed 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, place it directly 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.

[0061] (7) Vacuum distillation: Place the precious metal primary enrichment slag into 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, stabilize for 20 minutes, then slowly vent, adjust the pressure to 0.1-0.4 Pa, control the temperature at 130℃-150℃, control the distillation time at 30-45 minutes, and volatilize and condense the sulfur in the precious metal primary enrichment slag to obtain crude sulfur. The precious metal primary slag is further enriched by vacuum distillation to obtain precious metal secondary enrichment slag.

[0062] (8) Precious metal leaching: Pure hydrochloric acid + chlorine is used to leach the precious metal secondary enrichment slag. The leaching temperature is 85℃-95℃, the leaching time is 2-3h, the liquid-solid ratio is 4:1-5:1, and the chlorine introduction amount is 30%-50% of the mass of the precious metal secondary enrichment slag. The chlorine addition rate is controlled according to the reaction time and the amount of chlorine added. After the reaction is completed, precious metal leachate 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: Add zinc powder to the precious metal leachate in an amount of 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate. After reacting at 45-65°C for 2-3 hours, filter 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. 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, and kept at this temperature for 1-2 hours. 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, and the leaching time was 2.5 h. 27 mL of sulfuric acid and 300 mL of water were added. 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 leachate from 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 (after iron precipitation) in step (2) for 40 min. After the reaction was completed at room temperature, 305 mL of nickel-containing solution was obtained by filtration, which contained 28.27 g / L of nickel. 31.25 g of copper sulfide slag was obtained, which contained 48.23% of copper and 8.26% of nickel.

[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 nickel precipitation liquid was filtered to obtain a nickel-containing solution containing 0.008 g / L of nickel; 16.20 g of nickel sulfide slag was obtained, which contained 53.20% nickel. The nickel-containing 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) was reacted with 200 mL of a copper-nickel solution (prepared according to the conditions of step (2)). The reaction temperature was controlled at 95° C. After reacting for 3 h, 36.25 g of a low-nickel copper sulfide slag and a washed liquid were obtained by filtration. The low-nickel copper sulfide slag contained 51.26% copper and 0.53% nickel. The washed liquid was 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 hours. Immediately after the constant temperature is reached, filter it to obtain 45.50g of crude sulfur, which contains 91.25% sulfur. 12.31g of precious metal primary enrichment slag is obtained, which contains 73.28% sulfur, 784.11g / t gold, 898.52g / t platinum, and 724.18g / t palladium.

[0073] (7) Vacuum distillation: Place the precious metal primary enrichment slag from step (6) into 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 1.5×10 5 Pa, stabilize for 20 minutes, then slowly vent, adjust the pressure to 0.2 Pa, control the temperature at 135 ° C, 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%, 3103.66g / t of gold, 3556.52g / t of platinum, and 2866.44g / t of palladium.

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

[0075] (9) Zinc Powder Replacement: 2.96 g of zinc powder was added to the precious metal leachate from step (8). The mixture was reacted at 45°C for 3 h, and then filtered to obtain 0.96 g of precious metal sludge and a zinc-containing solution. The precious metal sludge contained 10,047.56 g / t gold, 11,511.64 g / t platinum, and 9,279.07 g / t palladium. The direct recovery rates for gold, platinum, and palladium were 99.92%, 99.91%, and 99.92%, respectively.

[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 hour. 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, and the leaching time was 3 h. 24 mL of sulfuric acid and 300 mL of water were added. 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 leachate from 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 content in the iron hydroxide slag was 40.13%.

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

[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 nickel precipitation liquid was filtered to obtain a nickel-containing solution containing 0.005 g / L of nickel; 10.38 g of nickel sulfide slag was obtained, which contained 51.25% nickel. The nickel-containing 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 filtration. 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, keep the temperature constant for 2 hours, and immediately filter it after the constant temperature is completed to obtain 50.13g of crude sulfur, of which the sulfur content is 93.16%, and 18.53g of precious metal primary enrichment slag, of which the sulfur content is 73.16%, 229.64g / t of gold, 163.37g / t of platinum, and 189.52g / t of palladium.

[0085] (7) Vacuum distillation: Place the precious metal primary enrichment slag from step (6) into 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 1.2×10 5 Pa, stabilize for 20 minutes, then slowly vent, adjust the pressure to 0.25 Pa, control the temperature at 140 ° C, control the distillation time for 40 minutes, and obtain 12.86g of crude sulfur, of which the sulfur content is 96.15%, and 3.33g of precious metal secondary enrichment slag, of which the sulfur content is 38.12%, 1277.84g / t of gold, 909.08g / t of platinum, and 1054.59g / t of palladium.

[0086] (8) Precious metal leaching: 15 mL of hydrochloric acid and 1.16 g of chlorine were added to leach the precious metal secondary enrichment slag from step (7). The leaching temperature was 95° C., the leaching time was 2 h, and the chlorine introduction rate was 9.67 mg / min. After the reaction was completed, precious metal leachate 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 leachate from step (8). The mixture was reacted at 45°C for 2 h, and then filtered to obtain 0.55 g of precious metal sludge and a zinc-containing solution. The precious metal sludge contained 7730.74 g / t of gold, 5500.06 g / t of platinum, and 6380.06 g / t of palladium. The direct recovery rates for 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 scope of protection of the present invention.

Claims

1. A process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur 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. After the reaction is completed, the leachate and leach residue are obtained. The amount of sulfuric acid added is 40% to 60% of the mass of the precious metal material in the hot filter residue, and the liquid-solid mass ratio is 3:1 to 4:

1. (2) Iron precipitation: sodium hydroxide is added to the leachate from step (1), the pH value is adjusted to 2.5-3.0, the reaction time is 40-60 min, and after the reaction is completed, the copper-nickel solution and iron hydroxide slag are obtained by filtration; (3) Copper precipitation: sodium sulfide is added to the copper-nickel solution in step (2), and after the reaction is completed, the nickel-containing solution and copper sulfide slag are obtained by filtration; the sulfur-copper mass ratio is controlled to be 0.62:1-0.72:1; (4) Nickel precipitation: sodium sulfide is added to the nickel-containing solution in step (3). After the reaction is completed, the nickel precipitation liquid and nickel sulfide slag are obtained by filtration. 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), 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: Dry the leaching residue from step (1), heat it at a constant temperature of 120-130°C for 1-2 hours, and filter it immediately after the constant temperature is reached to obtain the crude sulfur and precious metal primary enrichment residue; (7) Vacuum distillation: The precious metal primary enrichment slag from step (6) is placed in a vacuum furnace for vacuum distillation. The sulfur in the precious metal primary enrichment slag is volatilized and condensed to obtain crude sulfur. The precious metal primary enrichment slag is vacuum distilled to obtain precious metal secondary enrichment slag. (8) Precious metal leaching: hydrochloric acid and chlorine are added to leach the precious metal secondary enrichment slag from step (7). After the reaction is completed, precious metal leaching liquid and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation step; (9) Zinc powder replacement: zinc powder is added to the precious metal leaching solution in step (8), and after the reaction, the precious metal mud and zinc-containing solution are obtained by filtration; (10) Sulfur preparation: The crude sulfur produced by 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 residue 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 0.8-1.0 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, leachate and leach residue are obtained.

3. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residue according to claim 1, characterized in that: The specific steps of step (2) are as follows: iron precipitation: adjusting the pH value of the leachate in 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 in 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 and sulfur from hot filter residue 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 nickel precipitation liquid and nickel sulfide slag, and obtaining crude sodium sulfate after the nickel precipitation liquid is crystallized.

5. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residue 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 and sulfur from hot filter residue according to claim 1, characterized in that: The specific steps of step (6) are as follows: hot filtration: after drying the leaching 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.

7. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residue according to claim 1, characterized in that: The specific steps of step (7) are as follows: vacuum distillation: put the precious metal primary enrichment slag from step (6) into 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 ≥1.0×10 5 Pa, after stabilization 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 after volatilization and condensation 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 of step (7), the leaching temperature is 85℃-95℃, 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 leachate 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 residue according to claim 1, characterized in that: The specific steps of step (9) are as follows: zinc powder replacement: adding zinc powder to the precious metal leachate of step (8), the amount of zinc powder added being 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate, reacting at 45-65°C for 2-3 hours, and then filtering to obtain precious metal mud and zinc-containing solution; the specific steps of step (10) are as follows: sulfur preparation: directly placing the sulfur produced in the hot filtration step and the vacuum distillation step into a sealed crucible and heating it to 120°C-130°C, maintaining the temperature for 1-2 hours, and immediately filtering to obtain sulfur and filter residue after the temperature is maintained, 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 residue according to claim 1, characterized in that: The following steps are involved: (1) High-pressure oxygen leaching: Use sulfuric acid, oxygen and water to carry out oxygen pressure leaching on the hot filter residue. The leaching temperature is 120-150℃, the oxygen pressure is 0.8-1.0MPa, and the leaching time is 2-3h. Sulfuric acid is added in an amount of 40%-60% of the mass of the precious metal material in the hot filter residue. Water is added with a liquid-solid mass ratio of 3:1-4:

1. After the reaction is completed, leachate and leaching residue are obtained; (2) Iron precipitation: using sodium hydroxide to adjust the pH value of the leachate from step (1) to 2.5-3.0, the reaction time is 40-60 min, and after the reaction is completed at room temperature, the copper-nickel solution and iron hydroxide slag are obtained by filtration; (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, and the reaction time to be 40-60 min. After the reaction is completed at room temperature, filtering is performed to obtain the nickel-containing solution and copper sulfide slag; (4) Nickel precipitation: sodium sulfide nonahydrate is added to the nickel-containing solution in step (3), and the sulfur-nickel mass ratio is controlled to be above 0.6:

1. The reaction time is 40-60 min. After the reaction is completed at room temperature, the nickel precipitation liquid and nickel sulfide slag are obtained by filtration. 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 2.5-3h, filtering to obtain low-nickel copper sulfide slag and 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, 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 enrichment residue; (7) Vacuum distillation: Place the precious metal primary enrichment slag from step (6) into 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 ≥1.0×10 5 Pa, stabilize for 20 minutes, then slowly vent, adjust the pressure to 0.1~0.4Pa, control the temperature at 130℃-150℃, and control the distillation time at 30-45 minutes. The sulfur in the precious metal primary enrichment slag is volatilized and condensed to obtain crude sulfur. The precious metal primary slag is further enriched by vacuum distillation to obtain precious metal secondary enrichment slag. (8) Precious metal leaching: hydrochloric acid and chlorine are added to leach the precious metal secondary enrichment slag from step (7). The leaching temperature is 85°C-95°C, the leaching time is 2-3 hours, the liquid-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 leachate and precious metal leaching slag are obtained, and the precious metal leaching slag is returned to the vacuum distillation step; (9) Zinc powder replacement: Add zinc powder to the precious metal leachate from step (8), with the amount of zinc powder added being 9-15 times the total amount of gold, platinum and palladium in the precious metal leachate. React at 45-65°C for 2-3h and then filter to obtain precious metal mud and zinc-containing solution. (10) Preparation of sulfur: The sulfur produced by the hot filtration process and the vacuum distillation process is directly placed in a sealed crucible and heated to 120℃-130℃, and kept at this temperature for 1-2 hours. 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.

10. The process for comprehensive recovery of nickel, copper, gold, palladium, platinum and sulfur from hot filter residue 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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