Two-stage oxidation cobalt precipitation method
Through two sections of oxidation cobalt sinking methods, oxidation treatment is used using potassium permanganate and sodium excessive sulfate, respectively, solving the problem of low cobalt residue position and the inadequate method of cobalt -in -oxidation method in existing technologies, and realized the efficient enrichment and resources of cobalt metals and resources. Recycling.
Patent Information
- Application Number
- CN202411513203.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-01-24
AI Technical Summary
During the wet zinc smelting process, the existing cobalt depositing process leads to high zinc-cadmium content and low cobalt grade, and the primary oxidation method is not suitable for high manganese-containing solutions, resulting in low cobalt grade.
The two -stage oxidation cobalt -sinking method is adopted. First, the potassium permanganate is performed by oxidation to generate high cobalt solution and high manganese residue, and then secondary oxidation is performed through sodium sulfate to obtain high cobalt residue and low cobalt solution.
The efficient enrichment of cobalt metals is achieved, cobalt slag's quality is more than 30 times the rich compared with the purification residue, and the poverty of cobalt slag is avoided, and the efficiency of resource recovery and utilization of cadmium, manganese, and cobalt is improved.
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Figure CN119351775A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of mining engineering, and in particular relates to a two-stage oxidation cobalt precipitation method. Background Art
[0002] In the process of wet zinc smelting, cobalt metal mainly enters the purified slag through the zinc system purification process of high-temperature antimony salt to remove cobalt. The purified slag then adopts the process of "purified slag acid leaching-acid leaching liquid two-stage zinc powder replacement to recover cobalt-cobalt replacement after liquid zinc powder + antimony salt precipitation of cobalt", and cobalt enters the cobalt slag. However, the current cobalt precipitation process focuses on removing cobalt from the system, and the obtained cobalt slag has high zinc and cadmium content and low cobalt grade, and the resource utilization of cobalt metal has not been realized. At the same time, combined with the raw metal situation, the manganese content in the pre-cobalt precipitation liquid is relatively high (10 times the cobalt metal content), and the consumption of potassium permanganate precipitation by oxidation is too large; the manganese in the solution mainly exists in the form of manganese sulfate. After adding potassium permanganate, manganese dioxide precipitation is generated, which is mixed with the oxidized precipitated cobalt metal, resulting in cobalt depletion of cobalt slag and one-time oxidation precipitation of cobalt is not applicable to high manganese-containing solutions, and the output cobalt slag grade is still low. Therefore, it is very necessary to develop a method that can solve the above technical problems. Summary of the invention
[0003] The purpose of the present invention is to provide a two-stage oxidation cobalt precipitation method to solve the problems that the consumption of potassium permanganate precipitated by oxidation is too large, resulting in cobalt depletion of cobalt slag, and the single oxidation cobalt precipitation is not applicable to high manganese-containing solution, resulting in low grade of output cobalt slag.
[0004] The present invention provides a two-stage oxidation cobalt precipitation method, wherein the cobalt slag produced by the second-stage oxidation of the two-stage oxidation cobalt precipitation method is more than 30 times richer than the purified slag, and specifically comprises the following steps: S1. Preprocessing: 1) adding a sulfuric acid dilution solution or a waste electrolyte to the purified slag before cobalt precipitation by oxidation to obtain copper-containing slag a and a high-cadmium, high-cobalt and high-manganese cobalt precipitation pre-liquid b; 2) Add zinc powder to the high-cadmium, high-cobalt and high-manganese cobalt precipitation pre-liquid b to displace and remove cadmium to obtain sponge cadmium slag c and high-manganese and high-cobalt cobalt precipitation pre-liquid d; S2, one-stage oxidation: adding potassium permanganate to the high-manganese and high-cobalt cobalt precipitation pre-liquid d for oxidation to obtain a high-cobalt solution e and a high-manganese slag f; S3, second stage oxidation: sodium persulfate is added to the high cobalt solution e for oxidation to obtain high cobalt slag g and low cobalt solution h.
[0005] The specific operations are as follows: Pretreatment of the purified slag before cobalt precipitation by oxidation: the purified slag is leached with a sulfuric acid dilution or waste electrolyte, and the final leaching acid, leaching time, reaction temperature, and liquid-solid ratio are controlled to ensure the leaching rate of cobalt, and a cobalt precipitation pre-liquid with high cadmium, high cobalt, and high manganese is obtained; zinc powder is added to the cobalt precipitation pre-liquid to replace and remove cadmium, and the reaction time, reaction temperature, and amount of zinc powder added are controlled to ensure the cadmium removal rate, and filtered to obtain a cobalt precipitation pre-liquid with high cobalt and high manganese and a sponge cadmium slag, and the sponge cadmium slag is used for the subsequent extraction of sponge cadmium; Potassium permanganate is added to the obtained pre-cobalt precipitation solution to carry out an oxidation, and the reaction time, reaction temperature and amount of potassium permanganate added are controlled. The solution is filtered to obtain a high-cobalt solution and a high-manganese slag, and the high-manganese slag can be returned to the roasted sand leaching oxidation tank to replace the manganese powder. Sodium persulfate is added to the obtained high-cobalt precursor solution for secondary oxidation, and the reaction time, reaction temperature, amount of sodium persulfate added, and solution endpoint pH are controlled. The solution is filtered to obtain a high-cobalt slag and a low-cobalt solution. The high-cobalt slag is taken away, and the low-cobalt solution can be returned to the process as a slurry liquid.
[0006] The two-stage oxidation cobalt precipitation method of the present invention has the following advantages: (1) it realizes the enrichment of cobalt metal in high-manganese-containing slag, and the enrichment is more than 30 times; (2) the manganese precipitation effect is good, and the manganese content of the rear liquid is less than 50 mg / l; the cobalt precipitation effect is good, and the cobalt content of the rear liquid after cobalt precipitation is less than 15 mg / l; (3) it has good matching with production and realizes the resource recovery and utilization of cadmium, manganese and cobalt in the purified slag; (4) the first stage potassium permanganate oxidation of manganese generates manganese dioxide and returns it to the intermediate leaching for recycling, and avoids the depletion of cobalt slag, and the second stage sodium persulfate oxidation of cobalt does not introduce impurities; (5) the oxidant has good oxidation effect and low cost.
[0007] Potassium permanganate is used for oxidation and impurity removal. Potassium permanganate has strong oxidizing properties and is added in small amounts. The metallic manganese with high content and good metal activity is first precipitated into the slag. After filtration, the manganese dioxide slag with high purity and high manganese content is obtained and returned to the intermediate leaching for reuse; the solution with low impurity content after pretreatment is then subjected to secondary oxidation and cobalt precipitation with sodium persulfate to obtain cobalt slag with high Co content, thereby achieving the purpose of separating and purifying Co.
[0008] If potassium permanganate is used for both oxidations, the effect of the first oxidation will remain unchanged, but the grade of the cobalt slag from the second oxidation will be reduced. After potassium permanganate is reduced, manganese dioxide is generated and precipitated into the slag, which depletes the cobalt. The cobalt slag can only be enriched about 15 times compared with the purified slag.
[0009] If sodium persulfate is used for both oxidations, the oxidizing property of sodium persulfate is slightly weaker and the amount added is large. When the liquid after cobalt precipitation is returned to the previous process as slurry, the sodium content is high, which is not conducive to the system flow. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a schematic diagram of the process flow of the present invention; DETAILED DESCRIPTION
[0011] The present invention is further described below in conjunction with 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 belong to the protection scope of the present invention.
[0012] The cobalt slag produced by the second-stage oxidation of the two-stage oxidation cobalt precipitation method of the present invention is more than 30 times richer than the purified slag, and specifically comprises the following steps: S1. Preprocessing: 1) adding a sulfuric acid dilution solution or a waste electrolyte to the purified slag before cobalt precipitation by oxidation to obtain copper-containing slag a and a high-cadmium, high-cobalt and high-manganese cobalt precipitation pre-liquid b; 2) Add zinc powder to the high-cadmium, high-cobalt and high-manganese cobalt precipitation pre-liquid b to displace and remove cadmium to obtain sponge cadmium slag c and high-manganese and high-cobalt cobalt precipitation pre-liquid d; S2, one-stage oxidation: adding potassium permanganate to the high-manganese and high-cobalt cobalt precipitation pre-liquid d for oxidation to obtain a high-cobalt solution e and a high-manganese slag f; S3, second stage oxidation: sodium persulfate is added to the high cobalt solution e for oxidation to obtain high cobalt slag g and low cobalt solution h.
[0013] The leaching in step S1) is carried out by controlling the starting acid of leaching to 100-120 g / l, the end point pH to 4.0-5.0, the leaching time to 0.5-1.5 h, the reaction temperature to 70-90° C., and the liquid-to-solid ratio to (2-4):1.
[0014] In step 2) of S1, the zinc powder is used to replace cadmium by controlling the reaction time to 40-50 minutes and the reaction temperature to 60-70°C; wherein the amount of zinc powder added is 0.8-1.2 times the cadmium content.
[0015] The amount of potassium permanganate added in S2 is calculated based on the manganese sulfate content of the high-manganese and high-cobalt cobalt precipitation pre-liquid d, and is added at 0.8-0.9 times the theoretical amount.
[0016] The reaction conditions of the oxidation in S2 are: reaction time 1-2h, reaction temperature 70-80°C.
[0017] The amount of sodium persulfate added to S3 is 1.0-1.2 times the theoretical consumption of cobalt content.
[0018] The reaction conditions of the oxidation in S3 are: reaction time 0.5-1.5h, reaction temperature 60-80°C, and solution end point pH 4.5-5.0.
[0019] Considering the high manganese content in the raw materials, a two-stage precipitation method is adopted: the first oxidation and impurity removal, the metal (Mn) with high content and good metal activity is first precipitated into the slag, and a solution with low impurity content is obtained after filtration; the solution is used for secondary oxidation precipitation of cobalt to obtain an oxidized precipitated cobalt slag with a high Co content, thereby achieving the purpose of separating and purifying Co. The specific reaction equation is as follows: 2KMnO4+3MnSO4+2H2O=5MnO2↓+2H2SO4 2CoSO4+Na2S2O8+H2SO4=Co2(SO4)3+Na2SO4+H2O Co2(SO4)3+4H2O=2CoOOH↓+3H2SO4 Co2(SO4)3+6H2O=2Co(OH)3↓+3H2SO4 The present invention is further described below with specific implementation cases: Example 1 (1) Pretreatment of purified slag before cobalt oxidation precipitation Take a section of purification slag as raw material, weigh 100g of purification slag (149.5g of wet slag) into a 500ml beaker, dilute the waste electrolyte according to the acidity of 120g / l, use a measuring cylinder to measure 300ml and put it into the beaker containing the purification slag, leaching for 1.5h at 80℃, filter to obtain a high cadmium, high cobalt and high manganese cobalt precipitation pre-liquid; sample and analyze the Cd content in the obtained cobalt precipitation pre-liquid, calculate the amount of zinc powder added according to the Cd content, add zinc powder according to 1.0 times the theoretical amount, add zinc powder for 45min at 65℃, filter to obtain a high cobalt and high manganese solution and a sponge slag.
[0020] (2) One-stage oxidation The Mn content in the cobalt precipitation pre-liquid obtained in step (1) is analyzed by sampling, and the theoretical amount of potassium permanganate to be added is calculated according to the manganese sulfate content. Potassium permanganate is added at 0.9 times the theoretical amount, and an oxidation is carried out for 1.5 hours at a temperature of 75°C. The solution is filtered to obtain a high-cobalt solution and a high-manganese slag. The high-manganese slag can be returned to the roasted sand leaching oxidation tank for use instead of manganese powder.
[0021] (3) Secondary oxidation The Co content in the liquid after the primary oxidation obtained in step (2) is analyzed by sampling. The theoretical amount of sodium persulfate to be added is calculated according to the cobalt content. Sodium persulfate is added at 1.1 times the theoretical amount to carry out secondary oxidation for 1 hour at a temperature of 70°C. During the reaction, the pH of the solution is measured with a pH test paper. A sodium hydroxide solution with a concentration of 100 g / l is appropriately added to adjust the pH. The end point pH is controlled to be 5.0. After the reaction is completed, the liquid is filtered to obtain a high-cobalt slag and a low-cobalt solution. The high-cobalt slag is taken out, and the low-cobalt solution can be returned to the process as a slurry.
[0022] Comparative Example 1 (1) Pretreatment of purified slag before cobalt oxidation precipitation Take a section of purification slag as raw material, weigh 100g of purification slag (149.5g of wet slag) into a 500ml beaker, dilute the waste electrolyte according to the acidity of 120g / l, use a measuring cylinder to measure 300ml and put it into the beaker containing the purification slag, leaching for 1.5h at 80℃, filter to obtain a high cadmium, high cobalt and high manganese cobalt precipitation pre-liquid; sample and analyze the Cd content in the obtained cobalt precipitation pre-liquid, calculate the amount of zinc powder added according to the Cd content, add zinc powder according to 1.0 times the theoretical amount, add zinc powder for 45min at 65℃, filter to obtain a high cobalt and high manganese solution and a sponge slag.
[0023] (2) Two-stage oxidation Potassium permanganate is used for both oxidations. The effect of the first oxidation remains unchanged, but the grade of the cobalt slag from the second oxidation will be reduced. Potassium permanganate is reduced to generate manganese dioxide which is precipitated into the slag, which depletes the cobalt. The cobalt slag is enriched about 15 times compared with the purified slag.
[0024] Sodium persulfate is used in both oxidations. The oxidizing property of sodium persulfate is slightly weaker. According to the reaction equation, theoretically, the amount of sodium persulfate added is 1.5 times that of potassium permanganate. If the amount added is large, the liquid after cobalt precipitation will contain high sodium when it returns to the previous process to be used as slurry, which is not good for the system flow.
[0025] 2CoSO4+Na2S2O8+H2SO4=Co2(SO4)3+Na2SO4+H2O 6CoSO4+2KMnO4+4H2SO4=3Co2(SO4)3+K2SO4+2MnO2↓+4H2O.
Claims
1. A two-stage oxidation method for cobalt precipitation, characterized in that: The cobalt slag produced by the second-stage oxidation of the two-stage oxidation cobalt precipitation method has a grade of cobalt slag that is more than 30 times richer than the purified slag, and specifically comprises the following steps: S1. Preprocessing: 1) adding a sulfuric acid dilution solution or a waste electrolyte to the purified slag before cobalt precipitation by oxidation to obtain copper-containing slag a and a high-cadmium, high-cobalt and high-manganese cobalt precipitation pre-liquid b; 2) Add zinc powder to the high-cadmium, high-cobalt and high-manganese cobalt precipitation pre-liquid b to displace and remove cadmium to obtain sponge cadmium slag c and high-manganese and high-cobalt cobalt precipitation pre-liquid d; S2, one-stage oxidation: adding potassium permanganate to the high-manganese and high-cobalt cobalt precipitation pre-liquid d for oxidation to obtain a high-cobalt solution e and a high-manganese slag f; S3, second stage oxidation: sodium persulfate is added to the high cobalt solution e for oxidation to obtain high cobalt slag g and low cobalt solution h.
2. The method for two-stage oxidation precipitation of cobalt according to claim 1, characterized in that: The leaching in step S1) is carried out by controlling the starting acid of leaching to 100-120 g / l, the end point pH to 4.0-5.0, the leaching time to 0.5-1.5 h, the reaction temperature to 70-90° C., and the liquid-to-solid ratio to (2-4):
1.
3. The two-stage oxidation cobalt precipitation method according to claim 1, characterized in that: In step 2) of S1, the zinc powder is used to replace cadmium by controlling the reaction time to 40-50 minutes and the reaction temperature to 60-70°C; wherein the amount of zinc powder added is 0.8-1.2 times the cadmium content.
4. The two-stage oxidation cobalt precipitation method according to claim 1, characterized in that: The amount of potassium permanganate added in S2 is calculated based on the manganese sulfate content of the high-manganese and high-cobalt cobalt precipitation pre-liquid d, and is added at 0.8-0.9 times the theoretical amount.
5. The two-stage oxidation cobalt precipitation method according to claim 1, characterized in that: The reaction conditions of the oxidation in S2 are: reaction time 1-2h, reaction temperature 70-80°C.
6. The two-stage oxidation cobalt precipitation method according to claim 1, characterized in that: The amount of sodium persulfate added to S3 is 1.0-1.2 times the theoretical consumption of cobalt content.
7. The two-stage oxidation cobalt precipitation method according to claim 1, characterized in that: The reaction conditions of the oxidation in S3 are: reaction time 0.5-1.5h, reaction temperature 60-80°C, and solution end point pH 4.5-5.0.