Method for extracting enriched scandium from MHP

Abstract

The invention provides a method for extracting and enriching scandium from MHP, and belongs to the field of hydrometallurgy. The method has the advantages that the operation steps are simple, the scandium element in the MHP raw material is extracted and enriched by using the organic amine extraction agent N1923, the scandium chloride product obtained by the extraction, washing and reverse extraction of the N1923 extraction agent can effectively remove impurities and form an industrialization mode, the separation cost is lower, the flow is shorter, the scandium resource can be efficiently recycled, the MHP resource utilization rate is increased, and the method is suitable for industrial production. The method has great industrial potential.

Description

Technical Field

[0001] The invention relates to the field of hydrometallurgy, and in particular to a method for separating rare earth element scandium from MHP raw materials. Background Art

[0002] With the development of the domestic new energy vehicle field, the consumption of power lithium batteries has increased dramatically. With the increase in the demand for nickel sulfate for power lithium batteries, the processing volume of laterite nickel ore has shown explosive growth. The MHP obtained from laterite nickel ore contains a considerable amount of rare earth element scandium. A considerable amount of scandium products can be produced from the MHP used in the production of battery-grade nickel sulfate each year. Therefore, developing a method for extracting and enriching scandium from MHP is an effective way to fully utilize mineral resources and improve the production efficiency of enterprises. It can maximize the value of mineral resources and reduce the generation of industrial waste slag, which is of great significance to my country's environmental protection and economic and social development.

[0003] Prior art CN116790918A discloses a method for recovering scandium from an empty organic phase of nickel-cobalt extraction with P204. This method uses P204 for extraction and sodium hydroxide for back extraction, which has the disadvantages of great back extraction difficulty and long process flow. This technology uses organic amine extractant N1923 and hydrochloric acid for back extraction, which has the advantages of strong metal selectivity, short process flow and simple operation, and the raffinate after scandium extraction can directly enter the original production process to complete the extraction of nickel-cobalt resources, thereby realizing full utilization of resources. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for extracting and enriching scandium from MHP, and the specific scheme is as follows:

[0005] A method for extracting and enriching scandium from MHP comprises the following steps:

[0006] Step 1, mixing nickel cobalt hydroxide, a leaching agent and a reducing agent into a reactor for reaction;

[0007] Step 2: performing solid-liquid separation on the liquid obtained in step 1 to obtain MHP leaching solution and leaching residue, and returning the leaching residue to step 1 for leaching together with MHP;

[0008] Step 3, using a solvent extraction method to extract and separate the MHP leachate obtained in step 2, extracting the scandium element in the MHP leachate into an organic phase to obtain an extracted organic phase;

[0009] Step 4, washing the extracted organic phase obtained in step 3 with dilute acid to remove impurity ions such as Fe and Al in the organic phase to obtain a washed organic phase;

[0010] Step 5: The washed organic solution obtained in step 4 is stripped of scandium using a relatively high concentration of acid, and the stripping solution is dried to obtain a scandium chloride product.

[0011] In step 1, the nickel cobalt hydroxide is a nickel intermediate product prepared by high-pressure acid leaching technology using laterite nickel ore as raw material.

[0012] In step 1, the leaching agent is concentrated sulfuric acid, and the reducing agent is sodium pyrosulfite or sulfur dioxide gas.

[0013] The reaction conditions of step 1 are as follows: a solid-liquid ratio of 1:1, a reaction pH of 0-1, an amount of sodium pyrosulfite of 15-30 g / kg of raw material, a stirring reaction rate of 400-600 r / min, a stirring time of 2-4 h, and a reaction temperature of 50-90° C.

[0014] The solid-liquid separation method in step 2 is filtration, and the equipment used is a plate and frame filter press.

[0015] The solvent used in the solvent extraction method in step 3 is organic amine extractant N1923.

[0016] The extraction conditions in step 3 are as follows: the extraction phase ratio O / A=1:10-1:20, the pH value of the pre-extraction solution is 0-1, and the shaking time is 1-5 min.

[0017] The dilute acid used for washing in step 4 is 5-20% dilute sulfuric acid.

[0018] The higher concentration acid in step 5 is 1.0-6.0N hydrochloric acid.

[0019] The acid stripping conditions in step 5 are: stripping phase ratio O / A=5:1-1:1, and shaking time is 1-5min.

[0020] The method provided by the invention has not only a short process flow and simple operation, but also high product purity and low difficulty in process modification, and is of great significance for the efficient extraction of the rare earth element scandium.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention transforms the original MHP production process for battery-grade nickel sulfate, extracts and enriches the scandium element in the MHP leachate by solvent extraction, thereby improving resource utilization and economic benefits, and having little impact on the original process.

[0023] (2) The present invention uses organic amine extractant N1923 as the organic phase for extracting and enriching scandium, and controls the extraction of scandium under low acidity, which can effectively enrich scandium and simultaneously achieve separation from nickel and cobalt, thereby saving production costs and improving product quality.

[0024] (3) The present invention uses dilute sulfuric acid for multi-stage countercurrent washing in the washing process, which can effectively remove impurity ions such as Fe and Al in the organic phase and improve the purity of the scandium byproduct. The waste acid after washing can be returned to the leaching cycle for reuse, which is more advantageous in terms of resources and economy.

[0025] (4) The present invention uses hydrochloric acid of a certain concentration for stripping to obtain a scandium chloride product with excellent purity. The stripping process is simple, the flow is short, the cost is low, and it has great industrial potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a process flow chart for extracting and enriching scandium from MHP according to the present invention;

[0027] Figure 2 Shown is the purity chart of scandium chloride products obtained in Examples 1-3. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0029] Example 1

[0030] Step 1: Mix MHP with concentrated sulfuric acid and sodium metabisulfite at a solid-liquid ratio of 1:1, a sodium metabisulfite dosage of 15.0 g / kg raw material, and a reaction pH of 0.5, and place in a reactor for reaction, stirring the reaction at a rate of 450 r / min, a stirring time of 2 h, and a reaction temperature of 80°C;

[0031] Step 2: The liquid obtained in step 1 is subjected to solid-liquid separation to obtain MHP leaching liquid and leaching residue, and the leaching residue is returned to step 1 for leaching together with MHP; the solid-liquid separation method is filtration, and the equipment used is a plate-frame filter press;

[0032] Step 3, extracting and separating the MHP leaching solution obtained in step 2, the extraction conditions are: N1923 concentration is 10%, phase O / A is 1:15, pH value of the pre-extraction solution is 0.50, and the shaking time is 1.5min, to obtain scandium-containing organic;

[0033] Step 4: Wash the scandium-containing organic phase obtained in step 3 twice with dilute sulfuric acid. The washing conditions are: dilute sulfuric acid concentration of 10%, phase O / A=1:1, and washing time of 1.5 min to obtain a washed organic phase;

[0034] Step 5: The washed organic obtained in step 4 is stripped of the scandium element in the organic with hydrochloric acid. The stripping conditions are: hydrochloric acid concentration of 3.5N, phase O / A = 2:1, and shaking time of 1.5min. After drying, the scandium chloride product is obtained. The main components and some impurities analysis results are as follows:

[0035]

[0036] It can be seen from the table that the remaining impurities in the scandium chloride product are relatively low, with the Sc content reaching 16.86%. Calculated as ScCl3·6H2O, the purity is 97.23%.

[0037] Example 2

[0038] Step 1: Mix MHP with concentrated sulfuric acid and sodium metabisulfite at a solid-liquid ratio of 1:1, a sodium metabisulfite dosage of 15.0 g / kg raw material, and a reaction pH of 0.5, and place in a reactor for reaction, stirring the reaction at a rate of 450 r / min, a stirring time of 2 h, and a reaction temperature of 80°C;

[0039] Step 2: performing solid-liquid separation on the liquid obtained in step 1 to obtain MHP leaching solution and leaching residue, and returning the leaching residue to step 1 for leaching together with MHP;

[0040] Step 3, extracting and separating the MHP leaching solution obtained in step 2, the extraction conditions are: N1923 concentration is 25%, phase O / A is 1:15, pH value of the pre-extraction solution is 0.50, and the shaking time is 1.5min, to obtain scandium-containing organic;

[0041] Step 4: Wash the scandium-containing organic phase obtained in step 3 twice with dilute sulfuric acid. The washing conditions are: dilute sulfuric acid concentration of 10%, phase O / A=1:1, and washing time of 1.5 min to obtain a washed organic phase;

[0042] Step 5: The washed organic obtained in step 4 is stripped of the scandium element in the organic with hydrochloric acid. The stripping conditions are: hydrochloric acid concentration of 3.5N, phase O / A = 2:1, and shaking time of 1.5min. After drying, the scandium chloride product is obtained. The main components and some impurities analysis results are as follows:

[0043]

[0044] It can be seen from the table that the remaining impurities in the scandium chloride product are relatively low, with the Sc content reaching 16.49%. Calculated as ScCl3·6H2O, the purity is 95.10%.

[0045] Example 3

[0046] Step 1: Mix MHP with concentrated sulfuric acid and sodium metabisulfite at a solid-liquid ratio of 1:1, a sodium metabisulfite dosage of 15.0 g / kg raw material, and a reaction pH of 0.5, and place in a reactor for reaction, stirring the reaction at a rate of 450 r / min, a stirring time of 2 h, and a reaction temperature of 80°C;

[0047] Step 2: performing solid-liquid separation on the liquid obtained in step 1 to obtain MHP leaching solution and leaching residue, and returning the leaching residue to step 1 for leaching together with MHP;

[0048] Step 3, extracting and separating the MHP leaching solution obtained in step 2, the extraction conditions are: N1923 concentration is 25%, phase O / A is 1:15, pH value of the pre-extraction solution is 0.50, and the shaking time is 1.5min, to obtain scandium-containing organic;

[0049] Step 4: Wash the scandium-containing organic phase obtained in step 3 twice with dilute sulfuric acid. The washing conditions are: dilute sulfuric acid concentration of 10%, phase O / A=1:1, and washing time of 1.5 min to obtain a washed organic phase;

[0050] Step 5: The washed organic obtained in step 4 is stripped of the scandium element in the organic with hydrochloric acid. The stripping conditions are: hydrochloric acid concentration of 5.0N, phase O / A=2:1, and shaking time of 1.5min. After drying, the scandium chloride product is obtained. The main components and some impurities analysis results are as follows:

[0051]

[0052] It can be seen from the table that the remaining impurities in the scandium chloride product are relatively low, with the Sc content reaching 16.88%. Calculated as ScCl3·6H2O, the purity is 97.35%.

[0053] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for extracting and enriching scandium from MHP, characterized in that: The following steps are involved: Step 1, mixing nickel cobalt hydroxide, a leaching agent and a reducing agent into a reactor for reaction; Step 2: performing solid-liquid separation on the liquid obtained in step 1 to obtain MHP leaching solution and leaching residue, and returning the leaching residue to step 1 for leaching together with MHP; Step 3, using a solvent extraction method to extract and separate the MHP leachate obtained in step 2, extracting the scandium element in the MHP leachate into an organic phase to obtain an extracted organic phase; Step 4, washing the extracted organic phase obtained in step 3 with dilute acid to remove impurity ions such as Fe and Al in the organic phase to obtain a washed organic phase; Step 5: The washed organic solution obtained in step 4 is stripped of scandium using a relatively high concentration of acid, and the stripping solution is dried to obtain a scandium chloride product.

2. A method for extracting and enriching scandium from MHP according to claim 1, characterized in that: In step 1, the nickel cobalt hydroxide is a nickel intermediate product prepared by high-pressure acid leaching technology using laterite nickel ore as raw material.

3. A method for extracting and enriching scandium from MHP according to claim 1, characterized in that: In step 1, the leaching agent is concentrated sulfuric acid, and the reducing agent is sodium pyrosulfite or sulfur dioxide gas.

4. A method for extracting and enriching scandium from MHP according to claim 3, characterized in that: The reaction conditions of step 1 are as follows: a solid-liquid ratio of 1:1, a reaction pH of 0-1, an amount of sodium pyrosulfite of 15-30 g / kg of raw material, a stirring reaction rate of 400-600 r / min, a stirring time of 2-4 h, and a reaction temperature of 50-90 °C.

5. A method for extracting and enriching scandium from MHP according to claim 1, characterized in that: The solid-liquid separation method in step 2 is filtration, and the equipment used is a plate and frame filter press.

6. A method for extracting and enriching scandium from MHP according to claim 1, characterized in that: The solvent used in the solvent extraction method in step 3 is organic amine extractant N1923.

7. A method for extracting and enriching scandium from MHP according to claim 1, characterized in that: The extraction conditions in step 3 are as follows: the extraction phase ratio O / A=1:10-1:20, the pH value of the pre-extraction solution is 0-1, and the shaking time is 1-5 min.

8. The method for extracting and enriching scandium from MHP according to claim 1, characterized in that: The dilute acid used for washing in step 4 is 5-20% dilute sulfuric acid.

9. A method for extracting and enriching scandium from MHP according to claim 1, characterized in that: The higher concentration acid in step 5 is 1.0-6.0N hydrochloric acid.

10. The method for extracting and enriching scandium from MHP according to claim 1, characterized in that: The acid stripping conditions in step 5 are: stripping phase ratio O / A=5:1-1:1, and shaking time is 1-5 min.

Images