Method for separating and enriching scandium from cobalt nickel hydroxide leaching solution
Through the method of leaching scandium by complexing sodium fluoride precipitate and ammonium fluoride, the dispersion loss of scandium in the leaching solution in the laterite nickel ore and the "poisoning" brought about by the handy removal process are solved, and efficient separation and enrichment of scandium is achieved, forming economic benefits and clean production.
Patent Information
- Application Number
- CN202510501858.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-06-06
AI Technical Summary
Scandium in laterite nickel ore is leaching into the leaching solution during the high temperature leaching process of sulfuric acid, resulting in loss of dispersion in subsequent processes and "poisoning" problems to the removal process, making it difficult to effectively recover.
The scandium in the nickel-cobalt hydroxide leaching solution was separated by precipitation of sodium fluoride, and the scandium was leached by ammonium fluoride complexation, combining the acid-base regulation of ammonia water and hydrogen fluoride to achieve the decomposition and enrichment of scandium.
The scandium in the nickel hydroxide leaching liquid was separated and enriched. The scandium smelting enterprise obtained from scandium slag sold outside the scandium sludge formed economic benefits, and at the same time solved the adverse effects of scandium on the nickel and cobalt refining production line, and the process was clean and there was no wastewater production.
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Figure CN120099319A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of cobalt hydrorefining, and in particular relates to a method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution. Background Art
[0002] Nickel cobalt hydroxide material is usually a nickel-cobalt intermediate product obtained by high-pressure sulfuric acid leaching of laterite nickel ore. The scandium content in laterite nickel ore is usually 50~600g / t, and the scandium content of laterite nickel ore in different regions varies greatly. The production line for producing nickel cobalt hydroxide using high-pressure sulfuric acid leaching of laterite nickel ore usually processes laterite raw materials purchased from different raw material origins. Therefore, the scandium content in laterite nickel ore raw materials in different production periods fluctuates greatly, which makes it difficult to recover scandium from the smelting section of laterite nickel ore.
[0003] The main process of producing nickel-cobalt hydroxide products from laterite nickel ore using sulfuric acid high-pressure leaching process is: high-temperature sulfuric acid leaching - neutralization of leachate to remove iron and aluminum - neutralization of nickel and cobalt after iron and aluminum removal. Scandium in laterite nickel ore is leached into the leachate during high-temperature sulfuric acid leaching. Since the scandium in the solution begins to hydrolyze at pH 4.9 and is almost completely hydrolyzed at pH 5.45, and the end point pH of neutralization of iron and aluminum removal in laterite nickel ore leachate is about 4.2~4.5, and the pH of neutralization of nickel and cobalt precipitation is about 7.5~8.0, most of the scandium in laterite nickel ore is eventually enriched in nickel-cobalt hydroxide products.
[0004] The nickel-cobalt hydroxide products produced by laterite nickel ore are mostly used to produce nickel-cobalt sulfate or electro-nickel. The front-end processes of the production process are the same, which are: nickel-cobalt hydroxide reduction dissolution leaching - neutralization of the leachate to remove iron and aluminum - extraction and impurity removal of the liquid P204 after iron and aluminum removal, and the liquid after P204 impurity extraction enters the subsequent process. Scandium in the nickel-cobalt hydroxide material is dissolved into the leachate during the reduction leaching process. In order to reduce the dispersion loss of scandium in the leachate in the subsequent process and avoid the problem of organic "poisoning" caused by scandium in the subsequent extraction process, the present invention proposes a new method for separating and enriching scandium from the leachate without affecting the original smelting system. Summary of the invention
[0005] The purpose of the present invention is to provide a method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution. The method aims to solve the problem of recovering the scandium element in the nickel-cobalt hydroxide material, and to solve the problem of "poisoning" of the impurity-removing organic matter caused by scandium during the treatment of the nickel-cobalt hydroxide material. A process for cleanly separating and enriching scandium with simple process, low cost and no wastewater or waste gas emissions is proposed.
[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution comprises the following process steps: using sodium fluoride to precipitate scandium - using ammonium fluoride to complex and leach scandium from the precipitated scandium residue - using ammonia water to neutralize and decompose the scandium leaching solution to obtain the scandium residue - acidifying the decomposed solution with hydrogen fluoride and then returning to complex and leaching.
[0007] Preferably, the method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution comprises the following steps: Step 1. In a nickel-cobalt hydroxide leaching solution with a pH value of 2-3, NaF is added according to 1.2-2.0 times the theoretical consumption of calcium, magnesium and scandium in the leaching solution, so that the calcium, magnesium and scandium in the leaching solution form corresponding fluoride precipitation, and liquid-solid separation is performed to obtain calcium, magnesium and scandium slag; Step 2. The calcium magnesium scandium slag obtained in step 1 is leached by complexation with NH4F solution, and the leaching liquid-solid ratio is controlled to be 5-8:1. The ScF3 in the calcium magnesium scandium slag is complexed with NH4F to form a (NH4)3ScF6 complex which is dissolved in an ammonium fluoride solution to obtain a scandium-rich solution; Step 3. Add NH4OH to the scandium-rich solution in step 2, adjust the pH to 7.5-7.7, and the (NH4)3ScF6 complex will decompose into ScF3 precipitate and NH4F, and separate the liquid and solid to obtain scandium slag and the decomposed liquid; Step 4. After adjusting the pH of the decomposed liquid obtained in step 3 to 4.0-4.5 with HF, the solution is returned to the process of leaching scandium with calcium-magnesium-scandium slag, thereby realizing the recycling of the leaching liquid NH4F without generating any wastewater.
[0008] Preferably, the pH value of NH4F in step 2 is 4.0-4.5, and the concentration is 0.8-1.2 mol / L.
[0009] Preferably, the leaching reaction temperature in step 2 is 50-60° C., and the leaching reaction time is 3-5 hours.
[0010] The beneficial effects of the present invention are: 1. The present invention separates scandium from the nickel-cobalt hydroxide leachate by adding sodium fluoride for precipitation, and at the same time, the calcium and magnesium impurities in the leachate are also precipitated. The obtained calcium-magnesium-scandium slag uses a complex leaching method to separate calcium, magnesium and scandium, and uses ammonia water and hydrogen fluoride to adjust the acidity and alkalinity of the solution to achieve the decomposition of the complex and the recycling of the leaching agent ammonium fluoride, so as to obtain the scandium slag to achieve the separation and enrichment of scandium, and the whole process is clean production and no wastewater is generated. The invention realizes the separation and enrichment of scandium in the nickel-cobalt hydroxide leachate, and the obtained scandium slag is sold to the scandium smelting enterprise, which generates economic benefits while solving the adverse effects of scandium on the nickel-cobalt refining production line. It is a new and clean process for separating and enriching scandium from the material.
[0011] 2. The method of the present invention makes full use of the characteristics of scandium fluoride to separate scandium from nickel-cobalt hydroxide leaching solution, and to separate scandium from impurities such as calcium and magnesium, and finally to separate and enrich scandium. The scandium slag obtained is sold to scandium smelting enterprises, thereby generating economic benefits and solving the adverse effects of scandium on nickel-cobalt refining production lines. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0013] The present invention is further described below in conjunction with specific embodiments and process flow charts: The process of the present invention is further described by the following non-limiting examples to help understand the present invention and its advantages, but not to limit the scope of protection of the present invention, which is determined by the claims.
[0014] Such as process flow Figure 1 The method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution is shown. The typical composition of the nickel-cobalt hydroxide leaching solution involved in the method is (g / L): Ni 100-110, Co 10-12, Mn 8-10, Mg 2-4, Fe 0.2-0.5, Al 1.5-2.5, Sc 0.2-1.0. The new process for cleanly recovering scandium is to add NaF to the nickel-cobalt hydroxide leaching solution at a concentration of 1.2 times the theoretical consumption of calcium, magnesium and scandium to obtain calcium, magnesium and scandium slag; and to add NH with a concentration of 0.5 mol / L to obtain calcium, magnesium and scandium slag. 4 The calcium-magnesium-scandium slag was leached by complexing with F solution, and the leaching pH was controlled to be 4.0 and the leaching liquid-solid ratio was 3:1, thus obtaining a scandium-rich solution. 4 OH adjusts the pH of the scandium-rich solution to 7.5-7.7, so that the (NH 4 ) 3 S F 6 The complex decomposes to produce ScF 3 Precipitation, liquid-solid separation to obtain scandium slag; after decomposition, the liquid is adjusted to pH 4.0 with HF and then returned to the calcium-magnesium-scandium slag leaching process to achieve complex leaching scandium reagent NH 4 F is recycled, and no wastewater is generated during the production process. The scandium in the leaching solution has no effect on the original nickel-cobalt system during the separation and enrichment process, and the reagents for enriching scandium can be recycled without generating wastewater.
[0015] Example 1
[0016] Specific implementation process: 1) Take 1 ml of nickel-cobalt hydroxide leaching solution of the composition in Table 1. 3, placed in a stirred reactor, slowly added 170 kg of sodium fluoride, stirred for reaction for 30 minutes, filtered the solution, and obtained a calcium magnesium scandium slag weighing 12.38 kg. The analysis results of the liquid after precipitation are shown in Table 1, and the composition of the calcium magnesium scandium slag is shown in Table 2.
[0017] 2) Prepare 62 L of 0.8 mol / L ammonium fluoride solution, react with calcium magnesium scandium slag, control the reaction pH=4.0, the reaction temperature is 50°C, and the leaching reaction time is 3 h. Then filter to obtain a scandium-rich solution, the composition of which is shown in Table 2.
[0018]
[0019] 3) Slowly add ammonia water to the scandium-rich solution, control the reaction pH to 7.5-7.7, and separate the liquid and solid after 3 hours of reaction to obtain 1.22 kg of scandium slag and decomposed liquid. The composition of the scandium slag is shown in Table 3.
[0020] 4) Slowly add hydrofluoric acid to the decomposed liquid, adjust the pH to 4.0, and then return the calcium, magnesium and scandium slag to the leaching process for recycling.
[0021] Example 2
[0022] Specific implementation process: 1) Take 5 ml of nickel-cobalt hydroxide leaching solution of the composition in Table 4. 3 , placed in a stirred reactor, slowly added 120 kg of sodium fluoride, stirred for reaction for 30 minutes, filtered the solution, and obtained 57.65 kg of calcium magnesium scandium slag. The analysis results of the liquid after precipitation are shown in Table 4, and the composition of the calcium magnesium scandium slag is shown in Table 5.
[0023] 2) Prepare 460 L of 1.0 mol / L ammonium fluoride solution, react with calcium magnesium scandium slag, control the reaction pH to 4.5, the reaction temperature to 60°C, leaching reaction time to 5 h, filter, and obtain a scandium-rich solution, the composition of which is shown in Table 5.
[0024]
[0025] 3) Slowly add ammonia water to the scandium-rich solution, control the reaction pH to 7.5-7.7, react for 2 hours, separate the liquid and solid, and obtain 14.17 kg of scandium slag and decomposed liquid. The composition of the scandium slag is shown in Table 6.
[0026]
[0027] 4) Slowly add hydrofluoric acid to the decomposed liquid, adjust the pH to 4.0, and then return the calcium, magnesium and scandium slag to the leaching process for recycling.
Claims
1. A method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution, characterized in that: The method comprises the following process steps: using sodium fluoride to precipitate scandium - using ammonium fluoride to leach scandium from the precipitated scandium residue by complexation - using ammonia water to neutralize and decompose the scandium leaching solution to obtain the scandium residue - acidifying the decomposed solution with hydrogen fluoride and then returning to complexation leaching.
2. A method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution according to claim 1, characterized in that The following steps are involved: Step 1. In a nickel-cobalt hydroxide leaching solution with a pH value of 2-3, NaF is added according to 1.2-2.0 times the theoretical consumption of calcium, magnesium and scandium in the leaching solution, so that the calcium, magnesium and scandium in the leaching solution form corresponding fluoride precipitation, and liquid-solid separation is performed to obtain calcium, magnesium and scandium slag; Step 2. The calcium magnesium scandium slag obtained in step 1 is leached by complexation with NH4F solution, and the leaching liquid-solid ratio is controlled to be 5-8:1; ScF3 in the calcium magnesium scandium slag is complexed with NH4F to form a (NH4)3ScF6 complex which is dissolved in an ammonium fluoride solution to obtain a scandium-rich solution; Step 3. Add NH4OH to the scandium-rich solution in step 2, adjust the pH to 7.5-7.7, and the (NH4)3ScF6 complex will decompose into ScF3 precipitate and NH4F, and separate the liquid and solid to obtain scandium slag and the decomposed liquid; Step 4. After adjusting the pH of the decomposed liquid obtained in step 3 to 4.0-4.5 with HF, the solution is returned to the process of leaching scandium with calcium-magnesium-scandium slag, thereby realizing the recycling of the leaching liquid NH4F without generating any wastewater.
3. A method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution according to claim 2, characterized in that The pH value of NH4F in step 2 is 4.0-4.5, and the concentration is 0.8-1.2 mol / L.
4. A method for separating and enriching scandium from a nickel-cobalt hydroxide leaching solution according to claim 2, characterized in that The leaching reaction temperature in step 2 is 50-60° C., and the leaching reaction time is 3-5 hours.