Method for preparing electrolytic nickel through normal pressure and high pressure combined leaching of high-nickel matte

Abstract

The invention relates to a method for preparing electrolytic nickel through normal-pressure and high-pressure combined leaching of high-nickel matte, and belongs to the technical field of metal separation and enrichment. The method for preparing the electrolytic nickel through normal-pressure and high-pressure combined leaching of the high-nickel matte mainly comprises the steps of raw material preparation, normal-pressure leaching, solid-liquid separation, high-pressure reaction, metal recovery, impurity removal treatment and filtration and electrodeposition. According to the method for producing the electrolytic nickel through normal-pressure leaching and pressure leaching of the high-nickel matte, the risk that impurities are increased due to the fact that other production auxiliary materials are used is reduced, in the leaching process, steam, compressed air, normal pressure and pressure are optimized and combined innovatively, and leaching of nickel in the high-nickel matte is increased to the maximum extent. Black nickel generated in a production system is used for removing cobalt for the first time, it is guaranteed that the nickel content in the system reaches the standard while impurities are not increased, and meanwhile anode liquor obtained after electrodeposition enters an initial slurrying tank to be recycled.

Description

Technical Field

[0001] The invention belongs to the technical field of separation and enrichment of metals, and in particular relates to a method for preparing electrolytic nickel by leaching high-nickel matte under normal pressure and high pressure. Background Art

[0002] At the end of the 19th century, the chemical properties of nickel were gradually revealed, and nickel sulfate, as one of its important compounds, gradually entered the field of vision of industrial production. Nickel sulfate, as an intermediate product, is widely used in the production of electrolytic nickel, providing key raw materials for the manufacture of batteries, alloys and other nickel-based materials. With the rise of electric vehicles, renewable energy and high-performance battery technology, the importance of nickel sulfate as a core component of battery materials continues to increase. Modern metallurgical processes not only incorporate environmental protection concepts into production, reduce waste and exhaust emissions through innovative process design, but also promote the green transformation of nickel sulfate production. For example, the new atmospheric pressure and high pressure combined leaching technology makes the production of nickel sulfate more efficient and environmentally friendly, which not only optimizes the metal recovery rate but also reduces the burden on the environment.

[0003] Traditional hydrometallurgical technologies, such as atmospheric pressure leaching and high pressure leaching, have been applied in many fields, but these processes often expose many problems in actual operation. Although the atmospheric pressure leaching process is relatively simple, it relies on the use of a large amount of acid and chemicals, which leads to an increased environmental burden. The discharge of waste liquid and waste gas has an impact on the environment that cannot be ignored. At the same time, high acid consumption and increased equipment maintenance costs have caused high production costs, and the economy and processing efficiency of traditional processes are facing severe challenges. Problems such as uneven particle size and difficulty in accurately controlling reaction conditions have further restricted the further optimization of atmospheric pressure leaching technology.

[0004] Although high-pressure leaching technology has won a place with its high metal recovery rate, its high equipment investment and complex operation process undoubtedly increase the complexity of production. Operation under high-pressure conditions not only requires strict maintenance of equipment, but also puts forward higher requirements for safety management during the reaction process, which makes high-pressure leaching face greater pressure in terms of economy and environment. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing electrolytic nickel by leaching high-nickel matte at a combined pressure of normal and high pressure, in particular, by fine crushing and ultrasonic treatment, the leaching effect of the metal is optimized, and the environmental burden is reduced by modified additives. After entering the high-pressure stage, the technology of pulse injection of sulfuric acid makes the distribution of sulfuric acid more uniform, thereby improving the reaction efficiency. The black nickel produced in the production system is used to remove cobalt, and the nickel content in the system is guaranteed to meet the standard without increasing impurities. At the same time, the anolyte after electrolysis enters the initial slurry tank for recycling. This series of innovative measures not only significantly improves the extraction efficiency of nickel, but also shows significant advantages in terms of economy and environmental protection.

[0006] The specific technical solutions are as follows:

[0007] A method for preparing electrolytic nickel by leaching high nickel matte under normal pressure and high pressure. The raw materials of the method for preparing electrolytic nickel by leaching high nickel matte under normal pressure and high pressure are as follows: 2800-3000 parts of high nickel matte, 18000-20000 parts of deionized water, 300-500 parts of sulfuric acid, 60-120 parts of barium carbonate, 120-160 parts of black nickel, and 10-15 parts of modified clay. The specific steps of preparing electrolytic nickel by leaching high nickel matte under normal pressure and high pressure are as follows:

[0008] S1 Raw material preparation:

[0009] a. Take high-grade nickel matte in proportion, feed it into a jaw crusher at a feed rate of 100-200 kg / h, and crush it at 800-1200 rpm;

[0010] b. The crushed nickel matte particles are placed in a water quenching tank and quenched for 5 to 10 minutes;

[0011] c. The water-quenched high-matte nickel is mixed with steel ball grinding media at a ratio of 1:1.5 to 1:2 and added to a ball mill, and ground at a speed of 200 to 250 rpm for 2 to 4 hours;

[0012] d. The ground nickel matte is passed through a vibrating screen at a vibration frequency of 600 to 1200 rpm, with an amplitude of 2 to 4 mm, and sieved for 10 to 30 minutes. The sieved nickel matte is filtered using a pressure filter, with a filtration pressure of 0.5 to 1.0 MPa and a filtration speed of 5 to 10 L / min to obtain a slurry mixture;

[0013] S2 Normal pressure leaching: The slurry mixture is subjected to a normal pressure leaching, the air compressor pressure is 0.4-0.6 MPa, and the pressure is 1000-1500m 3Air is introduced at a flow rate of / h and mechanical stirring is performed, the stirring speed is set to 300-500rpm, sulfuric acid is added in proportion, the pH value is controlled to be 0.5-1, the temperature is 70-85°C, the time is 8-12 hours, and the pH after normal pressure leaching is 2.5-4.0 to obtain a leachate;

[0014] S3 solid-liquid separation: pump the leaching solution into the thickener for solid-liquid separation to obtain solid slag and leaching solution;

[0015] S4 high pressure reaction: the leaching solution in step S3 is used as the underflow, and the underflow is slurried and enters the high pressure reactor, the amount of sulfuric acid added is 1.6 to 1.8 times the metal content in the slag, the leaching temperature is 135 to 160°C, the pressure is 0.3 to 0.4 MPa, the leaching time is 4 to 5 hours, and the pH value after the reaction is completed is 1 to 2;

[0016] S5 Metal Recovery: The material after the reaction in step S4 is pumped into the thickener for solid-liquid separation again, and the solution enters step S2 for normal pressure leaching as bottom water. The solid phase residue is filtered and washed and then sent to the copper system to recover copper and other metals;

[0017] S6 impurity removal treatment:

[0018] a. Add barium carbonate to the leaching solution in proportion to remove impurities such as aluminum, copper, iron, manganese, and lead by precipitation. Control the pH to 5.0-5.5, the temperature to 60-80°C, and the precipitation time to 2-4 hours;

[0019] b. Continue to add black nickel (NiOOH) in proportion to precipitate cobalt, the temperature is 75-85°C, and the precipitation reaction time is 1-2 hours;

[0020] S7 filtration and electrowinning: the filtered filtrate after impurity removal is transferred to the electrowinning tank for diaphragm electrowinning to obtain electrolytic nickel, and the anode liquid is returned to step S2 as the bottom water for normal pressure leaching slurrying.

[0021] In some embodiments, during the water quenching in step S1, the flow rate of the water quenching tank needs to be controlled to be 1-3 L / min.

[0022] In some of the embodiments, in step S1, the crushed high nickel matte particles are further refined by ultrasonic treatment after water quenching, the ultrasonic frequency is 20 to 30 kHz, and the treatment time is 5 to 10 minutes.

[0023] In some of the embodiments, during the atmospheric pressure leaching process in step S2, a modified clay is added as an auxiliary agent, and the amount of the auxiliary agent added is 0.5% to 1.0% of the total amount of the leaching solution.

[0024] In some of the embodiments, in the high-pressure reaction of step S4, the sulfuric acid is added in a pulse injection method by adjusting the addition method of sulfuric acid so that the sulfuric acid is more evenly distributed in the high-pressure reactor, and the sulfuric acid injection pulse time interval is 2 to 5 minutes.

[0025] In some of the embodiments, during the filtration electrowinning process of step S7, a modified electrode material is used, and the electrode surface is coated with a highly conductive nano-coating to improve the electrolysis efficiency and the purity of the electrolytic nickel, and the thickness of the nano-coating is 50 to 100 nanometers.

[0026] This reaction has the following advantages:

[0027] (1) Yield improvement: Through fine crushing and ultrasonic treatment, the metal leaching effect is optimized, and the combination of normal pressure and high pressure leaching is used to fully utilize the reaction characteristics under different pressure conditions, thereby improving the yield.

[0028] (2) Reduced environmental impact: The use of optimized chemicals and modification aids in the atmospheric pressure leaching stage reduces the burden on the environment. The high pressure stage uses technologies such as pulse injection of sulfuric acid to evenly distribute sulfuric acid, further reducing environmental impact.

[0029] (3) Circularity of the production system: For the first time, the black nickel produced in the production system is used to remove cobalt, ensuring that the nickel content in the system meets the standard without increasing impurities. At the same time, the anode liquid after electrolysis enters the initial slurry tank for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the process of preparing electrolytic nickel by leaching high nickel matte under normal pressure and high pressure DETAILED DESCRIPTION

[0031] The following will combine the technical process steps, specific implementation conditions and materials in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] like Figure 1As shown, 2800 parts of high-matte nickel are taken in proportion, put into a jaw crusher at a feed rate of 150kg / h, crushed at 900rpm, and the crushed high-matte nickel particles are put into a water quenching tank and quenched for 7 minutes. The flow rate of the water quenching tank is 1.5L / min. It is refined by ultrasonic treatment, the ultrasonic frequency is 22kHz, and the treatment time is 5 minutes. The ultrasonic high-matte nickel is mixed with a steel ball grinding medium at a ratio of 1:1.5 and added to a ball mill, and ground at a speed of 200rpm for 2 hours. The ground high-matte nickel is passed through a vibrating screen at a vibration frequency of 700rpm, the amplitude is controlled to be 2mm, and sieved for 10 minutes. The sieved high-matte nickel is filtered using a pressure filter, the filtration pressure is set to 0.6MPa, and the filtration speed is 6L / min to obtain a slurry mixture for standby use.

[0034] Example 2

[0035] like Figure 1 As shown, 3000 parts of high-matte nickel are taken in proportion, put into a jaw crusher at a feed rate of 180kg / h, crushed at 1100rpm, and the crushed high-matte nickel particles are put into a water quenching tank and quenched for 8 minutes. The flow rate of the water quenching tank is 3L / min. It is refined by ultrasonic treatment, the ultrasonic frequency is 28kHz, and the treatment time is 8 minutes. The ultrasonic high-matte nickel is mixed with a steel ball grinding medium at a ratio of 1:2 and added to a ball mill, and ground at a speed of 240rpm for 4 hours. The ground high-matte nickel is passed through a vibrating screen at a vibration frequency of 1200rpm, the amplitude is controlled to be 4mm, and sieved for 20 minutes. The sieved high-matte nickel is filtered using a pressure filter, the filtration pressure is set to 1.0MPa, and the filtration speed is 10L / min to obtain a slurry mixture for standby use.

[0036] Example 3

[0037] like Figure 1 As shown, the slurry mixture in Example 1 was subjected to a normal pressure leaching, and 14 parts of a modified clay was added as an auxiliary agent, and the amount of the auxiliary agent added was 0.6% of the total amount of the leachate. Air was introduced and mechanical stirring was performed, and the stirring speed was set to 350rpm, 200 parts of sulfuric acid were added, and the pH value was controlled to be 1, the temperature was 70°C, and the time was 8 hours. After the normal pressure leaching was completed, the pH was 2.5, and the leachate was obtained. The leachate was pumped into a thickener for solid-liquid separation to obtain solid slag and leachate solution for standby use.

[0038] Example 4

[0039] like Figure 1As shown, the slurry mixture in Example 2 was subjected to a normal pressure leaching, 10 parts of a modified clay was added as an auxiliary agent, and the amount of the auxiliary agent added was 1.0% of the total amount of the leachate. Air was introduced and mechanical stirring was performed, the stirring speed was set to 500 rpm, 400 parts of sulfuric acid was added, the pH value was controlled to be 0.5, the temperature was 85°C, the time was 12 hours, and the pH after the normal pressure leaching was 4.0 to obtain a leachate, which was pumped into a thickener for solid-liquid separation to obtain solid slag and a leachate solution for standby use.

[0040] Example 5

[0041] like Figure 1 As shown, the leaching solution in Example 3 is used as the underflow, and the underflow enters the high-pressure reactor after slurrying. The amount of sulfuric acid added is 1.6 times the metal content in the slag. The sulfuric acid is added by pulse injection, and the time interval of the sulfuric acid injection pulse is 2 minutes.

[0042] The leaching temperature is 140° C., the pressure is 0.3 MPa, the leaching time is 4 hours, and the pH value after the reaction is 1; the material after the reaction is completed is pumped into a thickener for solid-liquid separation again, and the solution enters the atmospheric pressure leaching in Example 3 as bottom water, and the solid phase slag is filtered and washed and then sent to the copper system to recover copper and other metals;

[0043] Example 6

[0044] like Figure 1 As shown, the leaching solution in Example 4 is used as the bottom flow, and the bottom flow is slurried and enters the high-pressure reactor. The amount of sulfuric acid added is 1.8 times the metal content in the slag. The sulfuric acid is added by pulse injection, and the time interval of the sulfuric acid injection pulse is 5 minutes. The leaching temperature is 160°C, the pressure is 0.4MPa, the leaching time is 4.5 hours, and the pH value after the reaction is 2; the material after the reaction is pumped into the thickener for solid-liquid separation again, and the solution enters the normal pressure leaching in Example 4 as bottom water, and the solid phase slag is filtered and washed and sent to the copper system to recover copper and other metals;

[0045] Example 7

[0046] like Figure 1 As shown, 80 parts of barium carbonate are added to the leaching solution in Example 3 in proportion, and impurities such as aluminum, copper, iron, manganese, and lead are removed by precipitation, and the pH is controlled to be 5.5, the temperature is 60°C, and the precipitation time is 2.5 hours; 140 parts of black nickel (NiOOH) are continued to be added in proportion to precipitate cobalt, the temperature is 75°C, and the precipitation reaction time is 1 hour. The filtrate after impurity removal is transferred to the electrowinning tank for diaphragm electrowinning, using improved electrode materials, and the electrode surface is coated with a highly conductive nano coating with a thickness of 50 nanometers. Electrolytic nickel is obtained by electrowinning, and the anolyte is returned to Example 3 as the bottom water of the normal pressure leaching slurry.

[0047] The surface morphology of the prepared electrolytic nickel was observed and recorded according to GB / T 6516-2010 Electrolytic Nickel. It was found that the surface of the prepared electrolytic nickel was clean, free of sludge and oil, with an average thickness of 4.2 mm, no dendritic grains and dense pores on the edge, and no dense pores with a diameter greater than 3 mm on the surface, which met the national standard.

[0048] The chemical composition of the prepared electrolytic nickel was analyzed in accordance with "GB / T 6516-2010 Electrolytic Nickel" and "GB / T 8647.11-2019 Nickel Chemical Analysis Method". The results are shown in the following table. The test results meet the standards.

[0049] Table 1 Detection composition table of the electrolytic nickel product prepared in Example 7

[0050] project content Nickel plus cobalt (Ni+Co) w% 99.9955 Cobalt (Co) w% 0.0003 Copper (Cu) w% 0.000011 Iron (Fe) w% 0.000007 Manganese (Mn) w% 0.000005 Zinc (Zn) w% 0.000008 Carbon (C) w% 0.000004 Magnesium (Mg) w% 0.000003 Cadmium(Cd)w% 0.000001 Sulfur (S) w% 0.000007 Lead (Pb) w% 0.000001 Phosphorus (P) w% 0.000009

[0051] Example 8

[0052] like Figure 1 As shown, 110 parts of barium carbonate are added to the leaching solution in Example 4 in proportion, and impurities such as aluminum, copper, iron, manganese, and lead are removed by precipitation, and the pH is controlled to be 5.2, the temperature is 80°C, and the precipitation time is 4 hours; 155 parts of black nickel (NiOOH) are continued to be added in proportion to precipitate cobalt, the temperature is 85°C, and the precipitation reaction time is 2 hours. The filtrate after impurity removal is transferred to the electrowinning tank for diaphragm electrowinning, using improved electrode materials, and the electrode surface is coated with a highly conductive nano-coating with a thickness of 100 nanometers. Electrolytic nickel is obtained by electrowinning, and the anolyte is returned to Example 4 as the bottom water of the normal pressure leaching slurry.

[0053] The surface morphology of the prepared electrolytic nickel was observed and recorded according to GB / T 6516-2010 Electrolytic Nickel. It was found that the surface of the prepared electrolytic nickel was clean, free of sludge and oil, with an average thickness of 3.8 mm, no dendritic grains and dense pores on the edge, and no dense pores with a diameter greater than 3 mm on the surface, which met the national standard.

[0054] The chemical composition of the prepared electrolytic nickel was analyzed in accordance with "GB / T 6516-2010 Electrolytic Nickel" and "GB / T 8647.11-2019 Nickel Chemical Analysis Method". The results are shown in the following table. The test results meet the standards.

[0055] Table 1 Detection composition table of the electrolytic nickel product prepared in Example 7

[0056] project content Nickel plus cobalt (Ni+Co) w% 99.99682 Cobalt (Co) w% 0.00028 Manganese (Mn) w% 0.000005 Zinc (Zn) w% 0.000008 Carbon (C) w% 0.000004 Magnesium (Mg) w% 0.000003 Cadmium(Cd)w% 0.000001 Sulfur (S) w% 0.000007 Lead (Pb) w% 0.000001 Silicon (Si) w% 0.000004 Arsenic (As) w% 0.000003 Cadmium(Cd)w% 0.0000008

[0057] Technical personnel should note that: Although the present invention has been described according to the above specific implementation methods, the inventive concept of the present invention is not limited to this invention, and any modification using the inventive concept will be included in the scope of protection of this patent.

Claims

1. A method for preparing electrolytic nickel by leaching high nickel matte under normal pressure and high pressure, characterized in that: The raw material composition of the method for preparing electrolytic nickel by leaching high nickel matte with a combination of normal pressure and high pressure is as follows: 2800-3000 parts of high nickel matte, 18000-20000 parts of deionized water, 300-500 parts of sulfuric acid, 60-120 parts of barium carbonate, 120-160 parts of black nickel, and 10-15 parts of modified clay. The specific steps of preparing electrolytic nickel by leaching high nickel matte with a combination of normal pressure and high pressure are as follows: S1 Raw material preparation: a. Take high-grade nickel matte in proportion, feed it into a jaw crusher at a feed rate of 100-200 kg / h, and crush it at 800-1200 rpm; b. The crushed nickel matte particles are placed in a water quenching tank and quenched for 5 to 10 minutes; c. The water-quenched high-matte nickel is mixed with steel ball grinding media at a ratio of 1:1.5 to 1:2 and added to a ball mill, and ground at a speed of 200 to 250 rpm for 2 to 4 hours; d. The ground nickel matte is passed through a vibrating screen at a vibration frequency of 600 to 1200 rpm, with an amplitude of 2 to 4 mm, and sieved for 10 to 30 minutes. The sieved nickel matte is filtered using a pressure filter, with a filtration pressure of 0.5 to 1.0 MPa and a filtration speed of 5 to 10 L / min to obtain a slurry mixture; S2 Normal pressure leaching: The slurry mixture is subjected to a normal pressure leaching, the air compressor pressure is 0.4-0.6 MPa, and the pressure is 1000-1500m 3 Air is introduced at a flow rate of / h and mechanical stirring is performed, the stirring speed is set to 300-500rpm, sulfuric acid is added in proportion, the pH value is controlled to be 0.5-1, the temperature is 70-85°C, the time is 8-12 hours, and the pH after normal pressure leaching is 2.5-4.0 to obtain a leachate; S3 solid-liquid separation: pump the leaching solution into the thickener for solid-liquid separation to obtain solid slag and leaching solution; S4 high pressure reaction: the leaching solution in step S3 is used as the underflow, and the underflow is slurried and enters the high pressure reactor, the amount of sulfuric acid added is 1.6 to 1.8 times the metal content in the slag, the leaching temperature is 135 to 160°C, the pressure is 0.3 to 0.4 MPa, the leaching time is 4 to 5 hours, and the pH value after the reaction is completed is 1 to 2; S5 Metal Recovery: The material after the reaction in step S4 is pumped into the thickener for solid-liquid separation again, and the solution enters step S2 for normal pressure leaching as bottom water. The solid phase residue is filtered and washed and then sent to the copper system to recover copper and other metals; S6 impurity removal treatment: a. Add barium carbonate to the leaching solution in proportion to remove impurities such as aluminum, copper, iron, manganese, and lead by precipitation. Control the pH to 5.0-5.5, the temperature to 60-80°C, and the precipitation time to 2-4 hours; b. Continue to add black nickel (NiOOH) in proportion to precipitate cobalt, the temperature is 75-85°C, and the precipitation reaction time is 1-2 hours; S7 filtration and electrowinning: the filtered filtrate after impurity removal is transferred to the electrowinning tank for diaphragm electrowinning to obtain electrolytic nickel, and the anode liquid is returned to step S2 as the bottom water for normal pressure leaching slurrying.

2. The method for preparing electrolytic nickel by leaching high nickel matte by combining normal pressure and high pressure as claimed in claim 1, characterized in that: During the water quenching in step S1, the flow rate of the water quenching tank needs to be controlled to be 1 to 3 L / min.

3. The method for preparing electrolytic nickel by leaching high nickel matte by combining normal pressure and high pressure as claimed in claim 1, characterized in that: In step S1, the crushed high nickel matte particles are further refined by ultrasonic treatment after water quenching, the ultrasonic frequency is 20 to 30 kHz, and the treatment time is 5 to 10 minutes.

4. The method for preparing electrolytic nickel by leaching high nickel matte by combining normal pressure and high pressure as claimed in claim 1, characterized in that: In the normal pressure leaching process of step S2, a modified clay is added as an auxiliary agent, and the amount of the auxiliary agent added is 0.5% to 1.0% of the total amount of the leaching solution.

5. The method for preparing electrolytic nickel by leaching high nickel matte by combining normal pressure and high pressure as claimed in claim 1, characterized in that: In the high-pressure reaction of step S4, the sulfuric acid is added in a pulse injection method by adjusting the addition method to make the sulfuric acid more evenly distributed in the high-pressure reactor, and the sulfuric acid injection pulse time interval is 2 to 5 minutes.

6. The method for preparing electrolytic nickel by leaching high nickel matte by combining normal pressure and high pressure as claimed in claim 1, characterized in that: In the filtration electrowinning process of step S7, a modified electrode material is used, and the electrode surface is coated with a highly conductive nano-coating to improve the electrolysis efficiency and the purity of the electrolytic nickel. The thickness of the nano-coating is 50 to 100 nanometers.

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