Treatment process for reducing calcium and magnesium entrained in cobalt precipitation barren solution
By adding a fine filter device to separate the calcium and magnesium particles in the cobalt-poor liquid in the cobalt smelting process, the equipment scale and corrosion problems caused by the cobalt-poor liquid entrainment in the cobalt-poor liquid in wet metallurgy are solved, and the processing process is simplified and the treatment process is reduced. The effect of equipment damage.
Patent Information
- Application Number
- CN202410826630.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-25
- Publication Date
- 2025-02-18
AI Technical Summary
The cobalt-sinking liquid in wet metallurgy involves a large amount of calcium and magnesium particles, resulting in scaling and corrosion of the equipment of the grinding and impregnation system. The existing treatment process is long, there are many equipments, and the area is large, and it is impossible to directly improve scaling and corrosion problems.
After the secondary cobalt depositing process of the cobalt smelting process, the large calcium-magnesium solid particles and suspended tiny particles in the cobalt-lean liquid are separated by fine filtration, and the processing process is simplified.
After fine filtration, the calcium and magnesium content of the cobalt-polluted liquid is reduced, reducing the impact on the scale and corrosion of the grinding and immersion system equipment. The process is simple and the equipment is simple, without adding auxiliary materials.
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Figure CN119464749A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of hydrometallurgy, and specifically relates to a treatment process for reducing the entrainment of calcium and magnesium in cobalt-precipitating lean liquid, and is widely used in the treatment process of calcium-magnesium-containing alkaline wastewater in the fields of hydrometallurgy and the like. Background Art
[0002] In the process of cobalt metal smelting in the field of hydrometallurgy, since the cobalt precipitation process uses calcium oxide and magnesium oxide as auxiliary materials to adjust the pH, and the reaction process is relatively slow, part of the calcium oxide and magnesium oxide are not completely reacted and exist in the floating particles of the solution, resulting in a large number of calcium-magnesium-rich particles entrained in the cobalt precipitation lean solution. If it is directly used as CCD washing water, a large amount of calcium and magnesium impurities will be brought back to the grinding and leaching system, and calcium sulfate and magnesium sulfate will be formed in the acidic environment of grinding and leaching, which will aggravate the scaling and corrosion of the equipment. At present, the traditional treatment process for cobalt precipitation lean solution is to add calcium oxide to part (about 20%-25%) of the cobalt precipitation lean solution to further precipitate the magnesium ions therein, and after the magnesium precipitation, the solution is acidified and adjusted to neutral, and then mixed with the untreated lean solution (75%-80%) and returned to the system to gradually reduce the magnesium content of the system. This process cannot directly improve the problem of scaling and corrosion of equipment in the grinding and leaching system. The process is long, requires more equipment and occupies a large area. Many auxiliary materials and process control conditions are required, so it is urgent to study a method for treating cobalt-precipitated lean liquid, which can simplify the treatment process, reduce the calcium and magnesium content in the return grinding and leaching system, and thus reduce the scaling and corrosion effects on the equipment. Summary of the invention
[0003] The invention provides a treatment process for reducing calcium and magnesium entrained in cobalt precipitation barren solution, simplifies the treatment process, reduces the calcium and magnesium content in the return grinding and leaching system, and thus reduces the scaling and corrosion effects on equipment.
[0004] The technical solution of the present invention is: a treatment process for reducing the entrainment of calcium and magnesium in cobalt precipitation lean liquid, characterized in that: a fine filtration device is added after the secondary cobalt precipitation process in the cobalt smelting process, the liquid after the secondary cobalt precipitation is filtered through the fine filtration device to separate the solid large particles and suspended micro particles containing calcium and magnesium in the liquid after the cobalt precipitation.
[0005] Beneficial effects: The present invention adds a fine filtration device after the secondary cobalt precipitation process in the traditional cobalt smelting process, and uses the fine filtration device to filter the liquid after the secondary cobalt precipitation (i.e., the cobalt precipitation lean liquid) to separate large solid particles and suspended tiny particles containing calcium and magnesium in the cobalt precipitation lean liquid. The calcium and magnesium content of the treated cobalt precipitation lean liquid is lower than that of the untreated solution. Compared with the traditional process (part of the cobalt precipitation lean liquid is subjected to magnesium precipitation and neutralization to gradually reduce the magnesium content), this process has the advantages of simple process, large processing capacity, relatively simple equipment required, and no need to add other auxiliary materials. The calcium and magnesium content entrained in the treated cobalt precipitation lean liquid is lower than that of the untreated solution, and the solution reused in the grinding and leaching system has less impact on the scaling and corrosion of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 Process flow chart of the present invention. DETAILED DESCRIPTION
[0007] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below.
[0008] The present invention proposes a treatment process for reducing the entrainment of calcium and magnesium in cobalt precipitation lean liquor. In the traditional cobalt smelting process, a fine filtration device is added after the secondary cobalt precipitation process, and the liquid after the secondary cobalt precipitation (i.e., the cobalt precipitation lean liquor) is filtered through the fine filtration device to separate large solid particles and suspended tiny particles containing calcium and magnesium in the cobalt precipitation lean liquor.
[0009] The specific steps are:
[0010] The low-copper raffinate is treated with calcium oxide to remove iron, and magnesium oxide is added to precipitate cobalt once, followed by thickening and filter pressing, and then cobalt is precipitated twice. The cobalt precipitated solution is finely filtered to form a finely filtered solution, which is then returned to the grinding and leaching system;
[0011] The pH of the solution after cobalt precipitation is about 8. According to the dissolution product of magnesium hydroxide, the ksp of magnesium hydroxide at room temperature is 5.6*10 -12 , magnesium ions cannot exist in large quantities with hydroxide ions, so the magnesium element in the cobalt precipitation barren solution exists partly in the form of unreacted magnesium oxide solid particles or magnesium hydroxide;
[0012] The cobalt precipitation barren solution is filtered by fine filtration equipment, and only the solid impurities therein are filtered out, which has no effect on the pH value of the solution and does not require acid neutralization, and can be directly used for leaching and washing water.
[0013] Compared with the untreated solution, the amount of calcium and magnesium entrained in the treated solution is reduced, and recycling it to the grinding and leaching process can reduce the impact on equipment corrosion and scaling;
[0014] The fine filtration device used is one of the fine filtration methods or devices such as precision filter cloth filtration, ceramic membrane microporous filtration, PP / nylon (Nylonb) / polytetrafluoroethylene (PTEE) / polyvinylidene fluoride (PVDF) pleated filter element filtration, PP melt-blown filter element filtration, wire-wound filter element filtration, or a combination of two or more of the above filtration methods or devices.
[0015] Example:
[0016] A copper-cobalt ore smelting system currently uses traditional technology (neutralization after magnesium precipitation) to treat cobalt precipitation lean liquor. The processing capacity of the magnesium precipitation system is 1 / 5 of the cobalt precipitation lean liquor flux. The treated solution is mixed with the untreated cobalt precipitation lean liquor and enters the grinding and leaching system for reuse. The calcium and magnesium in the solution enter the acidic system of the grinding and leaching system and combine with sulfuric acid to form calcium sulfate and magnesium sulfate, which aggravates the scaling of the inner walls of pipelines and equipment and causes corrosion to the equipment. This process also consumes additional acid from the grinding and leaching system.
[0017] After replacing the traditional magnesium precipitation process with the new process, the processing capacity of cobalt precipitation lean solution has been greatly increased, and the calcium and magnesium content of the treated solution is significantly lower than that of the on-site process (as shown in the following table). The reduced calcium and magnesium content of the treated solution can reduce the impact on equipment corrosion and scaling, and can be directly used for CCD washing water, grinding water replenishment, etc., reducing the amount of new water added to the system.
[0018] Comparison table of solution ion content after treatment with new process and traditional process
[0019] index Mg(g / l) Ca(g / l) PH Cobalt-deposited lean solution 14.75 0.96 7.54 Solution after new process treatment 4.60 0.56 7.25 Mixed solution after traditional process 11.80 0.98 7.8
[0020] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A treatment process for reducing the entrainment of calcium and magnesium in cobalt-precipitating barren solution, characterized in that: In the cobalt smelting process, a fine filtration device is added after the secondary cobalt precipitation process, and the liquid after the secondary cobalt precipitation is filtered through the fine filtration device to separate the solid large particles and suspended tiny particles containing calcium and magnesium in the liquid after the cobalt precipitation.
2. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 1, characterized in that: The cobalt smelting process is low-copper raffinate, iron removal, primary cobalt precipitation, filter pressing, and secondary cobalt precipitation.
3. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 1, characterized in that: In the solution after cobalt precipitation, magnesium hydroxide ksp at room temperature is 5.6*10 -12 , magnesium ions cannot exist in large quantities with hydroxide ions, so the magnesium element in the cobalt-precipitating barren solution exists partly in the form of incompletely reacted magnesium oxide solid particles or magnesium hydroxide.
4. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 1, characterized in that: The amount of calcium and magnesium entrained in the treated solution is reduced compared with the untreated solution, and its reuse in the grinding and leaching process can reduce the impact of corrosion and scaling on equipment.
5. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 1, characterized in that: The cobalt precipitation barren solution is filtered by fine filtration equipment, and only the solid impurities therein are filtered out, which has no effect on the pH of the solution and does not require acid neutralization.
6. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 1, characterized in that: The fine filtration device is one of the following, or a combination of two or more, of precision filter cloth filtration, ceramic membrane microporous filtration, PP / nylon / polytetrafluoroethylene / polyvinylidene fluoride folded filter element filtration, PP melt-blown filter element filtration, and wire-wound filter element filtration.
7. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 2, characterized in that: Calcium oxide is added to remove iron.
8. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 2, characterized in that: The cobalt is precipitated once by adding magnesium oxide.
9. The process for reducing the entrainment of calcium and magnesium in the cobalt-precipitating barren solution according to claim 1, characterized in that: The cobalt precipitation liquid is finely filtered to form fine filtered liquid, and finally returned to the grinding and leaching process.