A method for leaching cobalt from high-manganese cobalt slag from hydrometallurgical zinc smelting

Abstract

The invention discloses a method for leaching cobalt from high-manganese cobalt slag produced by wet zinc smelting. The method comprises the following steps: subjecting the purified zinc smelting slag to two-stage countercurrent leaching, displacement and impurity removal, and oxidation precipitation to obtain high-manganese cobalt slag; crushing the high-manganese cobalt slag and grinding it into particles with a diameter of less than 0.1 cm; adding dilute sulfuric acid for acidification and slurry adjustment; then introducing a relatively high concentration of SO2 gas to react for a period of time, stopping the ventilation and continuing the reaction for a period of time; and under sufficient conditions, the SO2 gas will simultaneously reduce MnO2 in the high-manganese cobalt slag to Mn. 2+ After stopping ventilation, the Mn 2+ Continuing to synergistically leaching Co can greatly improve the leaching rate of cobalt, achieving a cobalt leaching rate of more than 95%. The present invention achieves efficient leaching of cobalt, the use of SO2 reduces the introduction of impurity ions, and at the same time utilizes Mn 2+ Co-leaching of Co can also effectively reduce the leaching of manganese. This method also has the advantages of low production cost and simple operation.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for leaching cobalt from high-manganese cobalt slag from hydrometallurgical zinc smelting. Background Art

[0002] Cobalt, a steely gray metal with corrosion and wear resistance, is a key raw material for the production of heat-resistant alloys, cemented carbides, anti-corrosion alloys, magnetic alloys, and catalysts. It is widely used in aerospace, medical, industrial, and defense industries. Utilizable cobalt resources in nature are extremely limited. While there are nearly a hundred cobalt-containing minerals, isolated cobalt deposits are virtually nonexistent. Most cobalt minerals are found in deposits associated with valuable metals such as copper, lead, and zinc, and have a relatively low cobalt grade. Despite being a major consumer of cobalt, my country's cobalt resources are relatively scarce, with 90% of its cobalt ore currently imported. Cobalt is produced as a byproduct of cobalt slag during the extraction of other metals. Recycling cobalt from secondary precipitation of cobalt-rich metal minerals as a raw material for cobalt smelting can reduce the environmental impact of cobalt slag as solid waste and alleviate the country's cobalt resource shortage to a certain extent.

[0003] Zinc smelting purification slag is subjected to two-stage countercurrent leaching, displacement removal, and oxidation precipitation to obtain high manganese cobalt slag. Cobalt mainly exists in the form of CoOOH. A reducing agent must be added to the sulfuric acid system to effectively convert it into Co 2+ The cobalt is leached into the solution in the form of a sulfite. Currently, most mainstream cobalt leaching processes use sodium sulfite or sodium metabisulfite as a reducing agent. However, the use of sodium sulfite or sodium metabisulfite introduces a large amount of sodium ions, making subsequent solution treatment difficult. Furthermore, the cost of sodium sulfite or sodium metabisulfite is relatively high. Traditional SO2 leaching methods, due to their low SO2 utilization rate, result in a low cobalt leaching rate. Therefore, it is extremely necessary to develop a method that can address these technical challenges. Summary of the Invention

[0004] The object of the present invention is to provide a method for leaching cobalt from high-manganese cobalt slag produced during hydrometallurgy of zinc.

[0005] The object of the present invention is achieved in that the method for leaching cobalt from high-manganese cobalt slag from hydrometallurgy zinc smelting comprises pretreatment and main reaction steps, specifically comprising:

[0006] A. Pre-treatment: crush and grind the high manganese cobalt slag from wet zinc smelting to obtain granular material a;

[0007] B. Main reaction:

[0008] 1) Adding dilute sulfuric acid to the granular material a to prepare slurry to obtain slurry b;

[0009] 2) SO2 gas is introduced into the slurry b for reaction for 2-6 hours, and then the gas is stopped and the reaction is continued for 12-24 hours. The cobalt-containing solution c and the cobalt-removed slag d are obtained by filtration. The cobalt-containing solution c is returned to the slurry preparation step, and the cobalt-removed slag d is used for the subsequent recovery of manganese metal.

[0010] The specific operations are as follows:

[0011] (1) Zinc smelting purification slag undergoes two-stage countercurrent leaching, displacement removal, and oxidation precipitation to obtain high manganese cobalt slag;

[0012] (2) Crushing the high manganese cobalt slag and grinding it into fine particles;

[0013] (3) Mix the high manganese cobalt slag particles with dilute sulfuric acid, stir until uniform, and then transfer into a three-necked flask;

[0014] (4) After a period of reaction with a relatively high concentration of SO2 gas, the gas is stopped and the reaction is continued for a period of time. Sufficient SO2 gas will simultaneously reduce the MnO2 in the high manganese cobalt slag to Mn 2+ After stopping ventilation, the Mn 2+ Continue to collaboratively leaching Co, and after leaching is completed, filter to obtain a cobalt-containing solution and a slag after removing cobalt;

[0015] In the above step (1), the cobalt content in the high manganese cobalt slag is 1% to 3%, and the manganese content is 5% to 50%;

[0016] In the above step (2), the diameter of the cobalt slag is controlled to be less than 0.1 cm;

[0017] In the above step (3), the liquid-to-solid ratio of the slurry is controlled at 5-10:1, and the concentration of dilute sulfuric acid is controlled at 0-30 g / L;

[0018] In the above step (4), the concentration of SO2 is controlled at 5% to 10%, the flow rate of SO2 is controlled at 0.3 to 0.7 liters per minute per liter of solution, the reaction time is controlled to be 12 to 36 hours after the addition of SO2 is stopped, the temperature of the entire process is controlled at 25°C to 75°C, the ventilation time is controlled to be 2 to 6 hours, and the stirring speed is controlled to be 300 to 500 r / min;

[0019] In the above step (4), the filtered cobalt-containing solution is returned to the front end for acidification and slurry adjustment, and circulated leaching is performed to increase the cobalt content in the solution;

[0020] In the above step (4), the slag after cobalt removal can be used for the subsequent recovery of manganese metal.

[0021] The advantages of the present invention are:

[0022] The present invention provides a method for leaching cobalt from high-manganese cobalt slag from hydrometallurgy zinc smelting. The use of SO2 avoids the introduction of impurity elements during the leaching process, and the subsequent solution does not need to undergo impurity removal operations, thereby saving purification costs. SO2 can be used through pipelines to achieve environmentally friendly operations, thereby alleviating environmental pressure on the operation site. By first introducing a high concentration of SO2 gas for a period of time, sufficient SO2 gas is used to simultaneously reduce MnO2 in the high-manganese cobalt slag to Mn. 2+ Then stop the ventilation and continue the reaction for a while, using the Mn 2+ Continuing to synergistically leaching Co can effectively improve the leaching efficiency of Co and reduce the leaching of manganese to a certain extent. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention fall within the scope of protection of the present invention.

[0024] The method for leaching cobalt from high-manganese cobalt slag from hydrometallurgy zinc smelting of the present invention comprises pretreatment and main reaction steps, specifically including:

[0025] A. Pre-treatment: crush and grind the high manganese cobalt slag from wet zinc smelting to obtain granular material a;

[0026] B. Main reaction:

[0027] 1) Adding dilute sulfuric acid to the granular material a to prepare slurry to obtain slurry b;

[0028] 2) SO2 gas is introduced into the slurry b for reaction for 2-6 hours, and then the gas is stopped and the reaction is continued for 12-24 hours. The cobalt-containing solution c and the cobalt-removed slag d are obtained by filtration. The cobalt-containing solution c is returned to the slurry preparation step, and the cobalt-removed slag d is used for the subsequent recovery of manganese metal.

[0029] The diameter of the granular material a described in step A is less than 0.1 cm.

[0030] The concentration of the dilute sulfuric acid in step B 1) is 0.1-30 g / L.

[0031] In step B 1), the liquid-to-solid volume ratio of the dilute sulfuric acid and the granular material a is (5-10):1.

[0032] B step 2) is to introduce SO2 gas into the slurry b, control the temperature at 25~75°C, and react for 2~6 hours under stirring conditions, then stop introducing SO2 gas, and react for 12~24 hours under stirring conditions at 25~75°C, and filter to obtain the cobalt-containing solution c and the cobalt-removed slag d.

[0033] The concentration of the SO2 gas is controlled at 5-10%.

[0034] The flow rate of the SO2 gas is controlled at 0.3~0.7L / min / L.

[0035] The stirring speed is 300-500 r / min.

[0036] The cobalt content in the hydrometallurgical zinc-rich high-manganese cobalt slag is 1-3%, and the manganese content is 20-50%.

[0037] The present invention will be further described below with reference to specific implementation cases:

[0038] Example 1

[0039] (1) The purified slag is subjected to two-stage countercurrent leaching, displacement removal, and oxidation precipitation to obtain high-manganese cobalt slag with a cobalt content of 2.97% and a manganese content of 40.26%;

[0040] (2) Crush the cobalt slag to a diameter of less than 0.1 cm and a weight of 3000 g;

[0041] (3) Take 30g of crushed cobalt slag and 300ml of dilute sulfuric acid solution with an acidity of 20g / L, mix until the slurry is uniform and transfer to a three-necked flask. Then, SO2 with a concentration of 5% is introduced into the mixed slurry at a flow rate of 0.6L per minute per liter of solution. The ventilation time is 2 hours. After the ventilation is completed, the reaction is continued for 24 hours. The temperature of the whole process is controlled at 50℃ and the stirring speed is controlled at 400~450r / min. The final cobalt leaching rate of the leaching solution reaches 95.26%, and the manganese leaching rate is 15.23%.

[0042] Example 2

[0043] (1) The purified slag is subjected to two-stage countercurrent leaching, displacement removal, and oxidation precipitation to obtain cobalt slag with a cobalt content of 2.97% and a manganese content of 40.26%;

[0044] (2) Crush the cobalt slag to a diameter of less than 0.1 cm and a weight of 3000 g;

[0045] (3) Take 30g of crushed cobalt slag and 300ml of dilute sulfuric acid solution with an acidity of 20g / L, mix until the slurry is uniform and then transfer to a three-necked flask. Then, SO2 with a concentration of 10% is introduced into the mixed slurry at a flow rate of 0.5L per minute per liter of solution. The ventilation time is 2 hours. After the ventilation is completed, the reaction is continued for 24 hours. The temperature of the whole process is controlled at 50℃ and the stirring speed is controlled at 400~450r / min. The final cobalt leaching rate of the leaching solution reaches 96.41%, and the manganese leaching rate is 20.87%.

[0046] Example 3

[0047] (1) The purified slag is subjected to two-stage countercurrent leaching, displacement removal, and oxidation precipitation to obtain cobalt slag with a cobalt content of 2.97% and a manganese content of 40.26%;

[0048] (2) Crush the cobalt slag to a diameter of less than 0.1 cm and a weight of 3000 g;

[0049] (3) Take 30g of crushed cobalt slag and 300ml of dilute sulfuric acid solution with an acidity of 20g / L, mix until the slurry is uniform and then transfer to a three-necked flask. Then, SO2 with a concentration of 10% is introduced into the mixed slurry at a flow rate of 0.5L per minute per liter of solution. The ventilation time is 2 hours. After the ventilation is completed, the reaction is continued for 36 hours. The temperature of the whole process is controlled at 50℃ and the stirring speed is controlled at 400~450r / min. The final cobalt leaching rate of the leaching solution reaches 98.94%, and the manganese leaching rate is 22.54%.

[0050] The above description of the present invention is more comprehensive and detailed in combination with the specification and preferred embodiments, but the protection scope of the present invention is not limited to the above specific embodiments.

[0051] Unless otherwise defined, all technical terms used above have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0052] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

Claims

1. A method for leaching cobalt from high-manganese cobalt slag produced during hydrometallurgy of zinc, characterized in that: The method for leaching cobalt from high-manganese cobalt slag from hydrometallurgy zinc smelting includes pretreatment and main reaction steps, specifically including: A. Pre-treatment: crush and grind the high manganese cobalt slag from wet zinc smelting to obtain granular material a with a diameter of less than 0.1 cm; B. Main reaction: 1) Adding 0.1-30 g / L dilute sulfuric acid to the granular material a to prepare slurry b; 2) SO2 gas with a concentration of 5-10% is introduced into the slurry b, the temperature is controlled at 25-75°C, and the reaction is carried out under stirring for 2-6 hours. Then the introduction of SO2 gas is stopped, the temperature is 25-75°C, and the reaction is carried out under stirring for 12-24 hours. The cobalt-containing solution c and the cobalt-removed slag d are obtained by filtration. The cobalt-containing solution c is returned to the slurry preparation step, and the cobalt-removed slag d is used for manganese metal recovery in the subsequent stage; The flow rate of the SO2 gas is to introduce the SO2 gas with a concentration of 5-10% into the slurry b at a flow rate of 0.3-0.7 L per minute per liter of solution.

2. The method for leaching cobalt from high-manganese cobalt slag from hydrozinc smelting according to claim 1, characterized in that: In step B 1), the liquid-to-solid volume ratio of the dilute sulfuric acid and the granular material a is (5-10):

1.

3. The method for leaching cobalt from high-manganese cobalt slag from hydrozinc smelting according to claim 1, characterized in that: The stirring speed is 300-500 r / min.

4. The method for leaching cobalt from high-manganese cobalt slag from hydrometallurgy zinc smelting according to claim 1, characterized in that: The cobalt content in the hydrometallurgical zinc-rich high-manganese cobalt slag is 1-3%, and the manganese content is 20-50%.