Method for wet separation of cobalt-iron alloy and preparation of iron oxide red
Through the method of low -acid immersion and oxygen pressure hydrolysis Shen iron reaction, the problem of high acid consumption of high acid and cobalt iron in the wet metallurgical process has been solved, and the high recovery rate of cobalt and the high -value use of iron is realized, reducing the process, which reduces the process. cost.
Patent Information
- Application Number
- CN202411588345.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-08
- Publication Date
- 2025-01-28
AI Technical Summary
When recovering cobalt from cobalt ferroalloys, the existing wet metallurgy process consumes high acid and is difficult to separate cobalt iron, resulting in high process costs and large cobalt losses.
Use low -acid leaching cobalt iron alloys, react with concentrated sulfuric acid after refining the ball grinding, generate cobalt iron immersion out, and then perform oxygen pressure hydrolysis Shen iron reactions. Burning is burned to get iron oxide red.
The high recovery rate and low acid consumption of cobalt, the high value utilization of iron, reduced the cost of process, and improved the efficiency of the separation of cobalt iron.
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Figure CN119372444A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of hydrometallurgy of secondary resources of nonferrous metals, and relates to a method for wet separation of cobalt-iron alloy and preparation of red iron oxide. Technical Background
[0002] Cobalt has extremely important applications in the fields of cemented carbide, catalysts, electronic devices, magnetic materials, battery manufacturing, and special coatings. Common methods for recovering associated cobalt from metallurgical by-products such as smelting slag include sulfuric acid roasting, reduction smelting, sulfide smelting, beneficiation, and wet leaching. Among them, the reduction roasting-magnetic separation enrichment process utilizes the iron affinity and magnetic properties of cobalt to achieve the simultaneous recovery of cobalt and iron in the slag. The recovered product is cobalt-iron alloy powder, which requires further separation of iron and cobalt to realize various applications of cobalt.
[0003] The method of recovering cobalt from cobalt-iron alloy is mainly based on hydrometallurgy, including acid leaching of cobalt-iron alloy, iron removal from leachate and other steps. Due to the low mass ratio of cobalt to iron in the alloy enriched by magnetic separation, the leaching process needs to consume a large amount of acidic leaching agent to react with iron, and the cobalt-iron leachate is obtained by precipitation method. The iron removal process also consumes a large amount of neutralizing agent and produces a large amount of iron slag, resulting in high process cost and large loss of cobalt. Iron is the most common impurity element in hydrometallurgy, so iron removal from solution is an important research content of hydrometallurgy. People have developed potassium iron alum precipitation method, goethite method, hematite method, etc. by using the hydrolysis reaction of iron. These methods require the addition of neutralizing agent during the hydrolysis and precipitation process of iron to maintain the hydrolysis reaction; when the iron content is high, the iron precipitation reaction needs to consume a large amount of neutralizing agent, which affects the economy of the process.
[0004] In view of the high acid consumption in acid leaching of high-iron and low-cobalt alloys and the large consumption of neutralizers in the precipitation method for removing iron from cobalt-iron leaching solution, the present invention proposes a method for recovering cobalt from cobalt-iron alloys and preparing red iron oxide, which can achieve high-value utilization of iron while selectively recovering cobalt. Summary of the invention
[0005] In view of the above technical problems, the present invention provides a method for wet separation of cobalt-iron alloy and preparation of red iron oxide. The present invention has high recovery rate of cobalt, low acid consumption and realizes high-value utilization of iron.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions.
[0007] A method for wet separation of cobalt-iron alloy and preparation of iron oxide comprises the following steps: Step 1: ball mill the cobalt-iron alloy powder raw material to grind the material particle size to less than 200 mesh, dry the water and set aside; Step 2: put the cobalt iron powder and water after ball milling in step 1 into a reaction kettle, slowly add concentrated sulfuric acid under stirring at a stirring speed of 150-300 rpm, react, and collect and recycle the gas generated by the reaction; Step 3: When the pH value of the solution in step 2 is greater than 4, the reaction is stopped, vacuum filtration is performed, and liquid-solid separation is performed to obtain a cobalt-iron leaching solution and a leaching residue (a); Step 4: inject the cobalt-iron leaching solution of step 3 into a high-pressure reactor with a volume ratio of 40% to 70%, fill it with high-pressure air, the filling pressure is 0.5-3 MPa, the stirring speed is 200-400 rpm, the temperature is increased to carry out oxygen pressure hydrolysis iron precipitation reaction, after a certain reaction time, the pressure in the reactor is released after the reaction is completed, the reaction materials are extracted, and iron oxide and cobalt-iron hydrolyzate are obtained after vacuum filtration; Step 5: Add 3 g / L to 5 g / L concentrated sulfuric acid to the cobalt-iron hydrolyzate in step 4 and react with the leaching residue (a) obtained in step 3, the reaction temperature is 60 to 90° C., and the reaction end point pH is greater than 4; Step 6: Repeat step 3 and step 4 5 to 6 times, and the obtained leaching residue is leaching residue (b), which is disposed harmlessly; the cobalt-iron hydrolyzate obtained is a high-cobalt hydrolyzate sent to the cobalt recovery system, and the iron oxide (hydrolysis iron precipitate) is washed with clean water to neutrality, dried and calcined at a certain temperature to obtain iron oxide red.
[0008] Furthermore, in step 1, the ball milling is wet ball milling, the water-ore mass ratio is 2:1, and the ball milling time is 10 min to 18 min, preferably 15 min.
[0009] Furthermore, in step 1, the particle size above 200 mesh accounts for more than 85%.
[0010] Furthermore, in step 2, the mass content of the cobalt iron powder in water is 50-200 g / L.
[0011] Furthermore, in step 2, the leaching agent is a low-concentration aqueous sulfuric acid solution, and the mass content of sulfuric acid does not exceed 25 g / L.
[0012] Furthermore, in step 2, the reaction conditions are 60-90°C, preferably 80°C.
[0013] Furthermore, in step 4, the reaction conditions for oxygen pressure hydrolysis iron precipitation are Fe ion concentration <20 g / L; reaction temperature 160°C~200°C, preferably 180°C; reaction time 3h~5h, preferably 4h.
[0014] Furthermore, in step 6, the calcination temperature is 700°C to 750°C.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows.
[0016] 1. Low-acid leaching of cobalt-iron alloy can obtain cobalt-iron leaching solution with low iron ion concentration, which can be directly subjected to oxygen pressure hydrolysis to precipitate iron. The obtained iron oxide has the advantages of high purity, small slag volume, and small loss of included cobalt.
[0017] 2. The sulfuric acid produced in the hydrolysis process is returned to the leaching process to achieve the recycling of sulfuric acid and improve the economy of the leaching process.
[0018] 3. Cobalt is continuously enriched during the hydrolysis-circulation leaching process of the leaching solution, which is beneficial to the subsequent recovery of cobalt.
[0019] 4. The technical problem of separation of iron and cobalt from high-iron and low-cobalt alloys has been solved, and iron is utilized in a high-value form in the form of red iron oxide. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is the XRD diagram of red iron oxide in Example 1.
[0021] Figure 2 This is the XRD pattern of goethite in comparative example 1. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.
[0023] A method for wet separation of cobalt-iron alloy and preparation of iron oxide comprises the following steps: Step 1: ball mill the cobalt-iron alloy powder raw material to grind the material particle size to less than 200 mesh, dry the water and set aside; Step 2: put the cobalt iron powder and water after ball milling in step 1 into a reaction kettle, slowly add concentrated sulfuric acid under stirring at a stirring speed of 150-300 rpm, react, and collect and recycle the gas generated by the reaction; Step 3: When the pH value of the solution in step 2 is greater than 4, the reaction is stopped, vacuum filtration is performed, and liquid-solid separation is performed to obtain a cobalt-iron leaching solution and a leaching residue (a); Step 4: inject the cobalt-iron leaching solution of step 3 into a high-pressure reactor with a volume ratio of 40% to 70%, fill it with high-pressure air, the filling pressure is 0.5-3 MPa, the stirring speed is 200-400 rpm, the temperature is increased to carry out oxygen pressure hydrolysis iron precipitation reaction, after a certain reaction time, the pressure in the reactor is released after the reaction is completed, the reaction materials are extracted, and iron oxide and cobalt-iron hydrolyzate are obtained after vacuum filtration; Step 5: Add 3 g / L to 5 g / L concentrated sulfuric acid to the cobalt-iron hydrolyzate in step 4 and react with the leaching residue (a) obtained in step 3, the reaction temperature is 60 to 90° C., and the reaction end point pH is greater than 4; Step 6: Repeat step 3 and step 4 5 to 6 times, and the obtained leaching residue is leaching residue (b), which is disposed harmlessly; the cobalt-iron hydrolyzate obtained is a high-cobalt hydrolyzate sent to the cobalt recovery system, and the iron oxide (hydrolysis iron precipitate) is washed with clean water to neutrality, dried and calcined at a certain temperature to obtain iron oxide red.
[0024] Furthermore, in step 1, the ball milling is wet ball milling, the water-ore mass ratio is 2:1, and the ball milling time is 10 min to 18 min, preferably 15 min.
[0025] Furthermore, in step 1, the particle size above 200 mesh accounts for more than 85%.
[0026] Further, in step 2, the leaching reaction is: Cobalt-iron alloy powder reacts with sulfuric acid to produce cobalt and iron leaching reaction: Co + H2SO4 = CoSO4 + H2↑ Fe + H2SO4 = FeSO4 + H2↑.
[0027] Furthermore, in step 2, the mass content of the cobalt iron powder in water is 50-200 g / L.
[0028] Furthermore, in step 2, the leaching agent is a low-concentration aqueous sulfuric acid solution, and the mass content of sulfuric acid does not exceed 25 g / L.
[0029] Furthermore, in step 2, the reaction conditions are 60-90°C, preferably 80°C.
[0030] Furthermore, in step 2, the gas generated by the reaction is hydrogen.
[0031] Further, in step 4, the oxygen pressure hydrolysis iron precipitation reaction is: 4FeSO4+ 4H2O + O2= 2Fe2O3↓+ 4H2SO4 4FeSO4+ 6H2O + O2= 4FeOOH↓+ 4H2SO4.
[0032] Furthermore, in step 4, the reaction conditions for oxygen pressure hydrolysis iron precipitation are Fe ion concentration <20 g / L; reaction temperature 160°C~200°C, preferably 180°C; reaction time 3h~5h, preferably 4h.
[0033] In step 5, the sulfuric acid produced by the hydrolysis in step 4 is used to continue to react with the unreacted iron and cobalt in the leaching residue.
[0034] Further, in step 6, the calcination temperature is 700°C to 750°C, and the specific reaction is: 2FeOOH = Fe2O3 + H2O.
[0035] Example 1.
[0036] The cobalt-iron alloy powder containing 87.71% Fe and 7.64% Co was wet-milled to less than 200 meshes, 100 g of the cobalt-iron alloy was weighed and added to a reactor, 1000 mL of water was added, 20 g of concentrated sulfuric acid was slowly added under stirring, the temperature was raised to 70 °C, the stirring speed was 250 rpm, the reaction was carried out for 45 min, and the pH value of the solution was 4.5; a cobalt-iron leaching solution and leaching residue (a) with an iron content of 18.92 g / L and a cobalt content of 1.58 g / L were prepared.
[0037] The cobalt-iron leaching solution was added into a closed high-pressure device and reacted for 4 h at a temperature of 180 °C, an air pressure of 2 MPa, a volume ratio of 60%, and a stirring speed of 400 rpm. After the reaction, the reaction materials were taken out, and the cobalt-iron hydrolyzate and iron oxide (hydrolysis iron precipitate slag) were obtained after liquid-solid separation.
[0038] After 3 g of concentrated sulfuric acid was added to the cobalt-iron hydrolyzate, it was reacted with the leaching residue (a) at a reaction temperature of 70°C. After 4 cycles, the leaching rates of iron and cobalt in the raw materials were 97.55% and 98.66%, respectively. The hydrolyzed iron precipitate slag was calcined at 720°C to obtain a total of 126.31 g of red iron oxide (containing 65.58% Fe and 0.019% Co) and 1050 mL of high-cobalt hydrolyzate (containing 2.59 g / L Fe and 7.16 g / L Co). The comprehensive recovery rate of cobalt was 98.35%, and 32 g of sulfuric acid was consumed.
[0039] Red iron oxide was dried at 105℃, and XRD analysis showed that its main component was Fe2O3, and the purity of Fe2O3 was 93.68%. Figure 1 shown.
[0040] Comparative example 1.
[0041] The cobalt-iron alloy powder containing Fe87.71% and Co7.64% was wet-milled to less than 200 meshes, 100 g of cobalt-iron alloy was weighed and added to the reactor, 1000 mL of water was added, 100 g of concentrated sulfuric acid was slowly added under stirring, the temperature was raised to 70°C, the stirring speed was 250 rpm, and the reaction was carried out for 45 minutes. After liquid-solid separation, 1000 mL of leaching solution with an iron content of 85.56 g / L and a cobalt content of 7.50 g / L was obtained, and the leaching rates of iron and cobalt were 97.55% and 98.17%, respectively.
[0042] The cobalt-iron leaching solution was heated to 95°C and stirred at 250 rpm. The pH of the solution was adjusted to 2.5-4 with a saturated sodium carbonate solution. 60 mL of hydrogen peroxide (30%) was added dropwise within 120 min for oxidative hydrolysis. The pH at the end of the reaction was controlled at 4.0. After liquid-solid separation, 1150 mL of iron removal liquid and 198.32 g of yellow iron slag were obtained. The iron slag contained 41.45% Fe and 0.41% Co. The comprehensive cobalt recovery rate in the cobalt-iron separation process was 87.53%, the iron removal rate was 93.72%, and 108.16 g of sodium carbonate were used. The iron slag was tested by XRD, and its main component was goethite, such as Figure 2 shown.
[0043] The above-mentioned Example 1 is the method of the present invention, and Comparative Example 1 is a method for removing iron from goethite. Comparing Example 1 with Comparative Example 1, Example 1 can achieve efficient separation of cobalt and iron in a high-iron cobalt-containing solution without using other reagents such as sodium carbonate and hydrogen peroxide, and is significantly superior to Comparative Example 1 in terms of sulfuric acid consumption, cobalt recovery rate, and quality of hydrolyzate.
Claims
1. A method for wet separation of cobalt-iron alloy and preparation of iron oxide, characterized in that: The following steps are involved: Step 1: ball mill the cobalt-iron alloy powder raw material to grind the material particle size to less than 200 mesh, dry the water and set aside; Step 2: put the cobalt iron powder and water after ball milling in step 1 into a reaction kettle, slowly add concentrated sulfuric acid under stirring at a stirring speed of 150-300 rpm, react, and collect and recycle the gas generated by the reaction; Step 3: When the pH value of the solution in step 2 is greater than 4, the reaction is stopped, vacuum filtration is performed, and after liquid-solid separation, a cobalt-iron leaching solution and leaching residue a are obtained; Step 4: inject the cobalt-iron leaching solution of step 3 into a high-pressure reactor with a volume ratio of 40% to 70%, fill it with high-pressure air, the filling pressure is 0.5-3 MPa, the stirring speed is 200-400 rpm, the temperature is increased to carry out oxygen pressure hydrolysis iron precipitation reaction, after a certain reaction time, the pressure in the reactor is released after the reaction is completed, the reaction materials are extracted, and iron oxide and cobalt-iron hydrolyzate are obtained after vacuum filtration; Step 5: Add 3 g / L-5 g / L concentrated sulfuric acid to the cobalt-iron hydrolyzate in step 4 and react with the leached residue a obtained in step 3, the reaction temperature is 60-90°C, and the reaction end point pH is greater than 4; Step 6: Repeat step 3 and step 4 5 to 6 times, and the obtained leaching residue is leaching residue b, which is disposed harmlessly; the cobalt-iron hydrolyzate is high-cobalt hydrolyzate and sent to the cobalt recovery system, and the iron oxide is washed with clean water to neutrality, dried and calcined at a certain temperature to obtain iron oxide red.
2. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In the step 1, the ball milling is wet ball milling, the water-ore mass ratio is 2:1, and the ball milling time is 10 min to 18 min.
3. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In step 1, the particle size of 200 mesh and above accounts for more than 85%.
4. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In the step 2, the mass content of the cobalt iron powder in water is 50-200 g / L.
5. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In step 2, the leaching agent is a low-concentration sulfuric acid aqueous solution, and the mass content of sulfuric acid does not exceed 25g / L.
6. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In the step 2, the reaction condition is 60-90°C.
7. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In step 4, the reaction conditions for oxygen pressure hydrolysis iron precipitation are Fe ion concentration <20 g / L; reaction temperature 160° C.~200° C.; and reaction time 3 h~5 h.
8. The method for wet separation of cobalt-iron alloy and preparation of iron oxide according to claim 1, characterized in that: In step 6, the calcination temperature is 700°C to 750°C.