Preparation method of molybdenum extracting agent NP191 for alkaline system

Abstract

The invention discloses a preparation method of a molybdenum extracting agent NP191 for an alkaline system, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: adding pyridine with the concentration of 10-15 mol / L into a container, taking ethanol as a reaction solvent, heating to 70-75 DEG C, adding an amination reagent with the concentration of 10-12 mol / L, and reacting for 8-12 minutes; adding an alkaline reagent as an accelerant, heating to 80-85 DEG C after the alkaline reagent is dissolved, introducing oxygen under a constant-temperature stirring condition, keeping the oxygen partial pressure in the reaction at 2-4 MPa, and reacting for 6-8 hours; after the reaction is finished, cooling the reaction mixture to room temperature, adjusting the pH value to be neutral by using dilute acid, filtering the precipitate, and washing off impurities; and carrying out secondary dissolution and recrystallization purification on the obtained solid by using ethanol, dissolving the product into a solution with the concentration of 50% by using a non-polar solvent, and mixing the solution with tributyl phosphate according to the volume ratio of 1: 1 to obtain the target molybdenum extraction agent NP191. According to the molybdenum extraction agent NP191 prepared through the method, the extraction rate of molybdenum can be stabilized at 98% or above, main raw materials and solvents used in the preparation process are environmentally friendly, environmental pollution is reduced, and the preparation method is simple, easy to implement and suitable for industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrometallurgy, and particularly relates to a preparation method of a molybdenum extractant NP191 for an alkaline system. Background Art

[0002] Molybdenum, as an important strategic metal, is widely used in fields such as steel, chemical industry, and electronics. At present, the extraction of molybdenum mainly adopts the oxidation roasting-ammonia leaching method, but this process has problems such as high sulfur dioxide emissions and low molybdenum recovery rate. In recent years, the solvent extraction method has become a research hotspot for molybdenum extraction due to its advantages such as high efficiency and good selectivity. However, in an alkaline system, existing molybdenum extraction reagents generally have problems such as poor selectivity, difficult stripping, and environmental pollution, and it is difficult to meet the requirements of industrial production.

[0003] In an alkaline system, commonly used molybdenum extraction reagents mainly include amine extractants (such as N235, N263) and phosphorus extractants (such as TBP, P204). However, these extractants have the following problems: ① Amine extractants: have poor selectivity for molybdenum, are prone to co-extract impurity ions, and are difficult to strip; ② Phosphorus extractants: are prone to emulsification in an alkaline system, resulting in difficult phase separation, and are highly corrosive to equipment. Therefore, it is of great significance to develop a preparation method of a new type of molybdenum extractant that is efficient, has good selectivity, is easy to strip, and is environmentally friendly in an alkaline system. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a molybdenum extractant NP191 for an alkaline system.

[0005] The purpose of the present invention is achieved as follows: The preparation method of the molybdenum extractant NP191 for the alkaline system includes the following steps: Add pyridine with a concentration of 10 - 15 mol / L into a reaction vessel, use ethanol as a reaction solvent, heat up to 70 - 75 °C, after reaching the reaction temperature, add an aminoating reagent with a concentration of 10 - 12 mol / L, and stir and react for 8 - 12 min; Add an alkaline reagent as a promoter, after the alkaline reagent is completely dissolved, heat up to 80 - 85 °C, under the condition of constant temperature stirring, introduce oxygen, and keep the oxygen partial pressure during the reaction at 2 - 4 MPa, and the reaction time is 6 - 8 h; After the reaction is completed, cool the reaction mixture to room temperature, adjust the pH value to neutral with dilute acid, filter the precipitate, and wash to remove impurities; The obtained solid is redissolved and recrystallized with ethanol for further purification, and the obtained product is dissolved in a non-polar solvent to form a 50% solution, and mixed with tributyl phosphate in a volume ratio of 1:1, then the target molybdenum extractant NP191 for the alkaline system can be obtained.

[0006] Compared with the prior art, the present invention has the following advantages: ① High efficiency and selectivity: In the molecular structure of the molybdenum extractant NP191 prepared by the technical solution of the present invention, a specific pyridine nitrogen-containing ring is introduced, which can form a stronger coordination bond with molybdenum ions, enabling it to form a stable complex with molybdenum ions in an alkaline system. After mixing with tributyl phosphate, the extraction selectivity and stripping efficiency can be further improved. The molybdenum extraction rate can be stabilized above 98%, and the efficient separation of molybdenum from copper, zinc, arsenic, indium, and germanium metals in the solution can be achieved. Molybdenum enters the organic phase, and the impurity elements remain in the raffinate.

[0007] ② Environmentally friendly: The main raw materials and solvents used in the preparation process are all environmentally friendly types, reducing environmental pollution.

[0008] ③ Simple operation: The preparation method is simple and easy to implement, suitable for industrial production. Detailed implementation method

[0009] The present invention will be further described below, but it is not limited to the present invention in any way. Any transformation or replacement based on the teachings of the present invention falls within the protection scope of the present invention.

[0010] The preparation method of the molybdenum extractant NP191 used in the alkaline system includes the following steps: Add pyridine with a concentration of 10 - 15 mol / L to the reaction vessel, use ethanol as the reaction solvent, heat up to 70 - 75 °C. After reaching the reaction temperature, add an amination reagent with a concentration of 10 - 12 mol / L, and stir and react for 8 - 12 min; Add an alkaline reagent as a promoter. After the alkaline reagent is completely dissolved, heat up to 80 - 85 °C. Under the condition of constant temperature stirring, introduce oxygen, and keep the oxygen partial pressure during the reaction at 2 - 4 MPa. The reaction time is 6 - 8 h; After the reaction is completed, cool the reaction mixture to room temperature, adjust the pH value to neutral with dilute acid, filter the precipitate, and wash to remove impurities; The obtained solid is redissolved and recrystallized with ethanol for further purification. The obtained product is dissolved in a non-polar solvent to form a 50% solution, and mixed with tributyl phosphate at a volume ratio of 1:1 to obtain the target molybdenum extractant NP191 for the alkaline system.

[0011] The volume ratio of the pyridine to the amination reagent is 1 - 1.2:1.

[0012] After adding the amination reagent, the reaction time is preferably 10 min.

[0013] The amination reagent is any one of hydroxylamine (NH2OH), carbamate (NH2CO2R), and sulfamic acid (H2NSO3H).

[0014] The addition amount of the alkaline reagent should ensure that the pH value of the reaction system is 9 - 12.

[0015] The alkaline reagent is any one of sodium hydroxide, sodium carbonate, sodium bicarbonate, and ammonia water.

[0016] The dilute acid is any one of sulfuric acid with a concentration of 0.1 - 2 mol / L, hydrochloric acid with a concentration of 0.1 - 1 mol / L, and nitric acid with a concentration of 0.1 - 1 mol / L.

[0017] The non - polar solvent is any one of kerosene, n - hexane, cyclohexane, n - dodecane, and petroleum ether, and preferably kerosene.

[0018] Example 1

[0019] Preparation of molybdenum extraction agent NP191 Add pyridine with a concentration of 10 mol / L into the reaction vessel, use ethanol as the reaction solvent, heat up to 70 °C. After reaching the reaction temperature, add hydroxylamine with a concentration of 12 mol / L. The volume ratio of pyridine to hydroxylamine is 1.2:1, and stir and react for 10 min.

[0020] Add sodium carbonate as a promoter. After the sodium carbonate is completely dissolved, keep the pH value of the system at 9, heat up to 80 °C, and under the condition of constant - temperature stirring, introduce oxygen, keep the oxygen partial pressure during the reaction at 4 MPa, and the reaction time is 6 h.

[0021] After the reaction is completed, cool the reaction mixture to room temperature, adjust the pH value to neutral with 0.5 mol / L sulfuric acid, filter the precipitate, and wash it with deionized water at room temperature to remove impurities.

[0022] The obtained solid is redissolved and recrystallized with ethanol for further purification. The obtained product is dissolved in petroleum ether to form a 50% solution by volume, and mixed with tributyl phosphate at a volume ratio of 1:1, then the molybdenum extraction agent NP191 for the target alkaline system can be obtained.

[0023] Example 2

[0024] Preparation of molybdenum extraction agent NP191 Add pyridine with a concentration of 12 mol / L into the reaction vessel, use ethanol as the reaction solvent, heat up to 75 °C. After reaching the reaction temperature, add carbamate with a concentration of 10 mol / L. The volume ratio of pyridine to carbamate is 1:1, and stir and react for 12 min.

[0025] Add sodium hydroxide as a promoter. After the sodium hydroxide is completely dissolved, keep the pH value of the system at 12, heat up to 85 °C, and under the condition of constant - temperature stirring, introduce oxygen, keep the oxygen partial pressure during the reaction at 2 MPa, and the reaction time is 8 h.

[0026] After the reaction is completed, cool the reaction mixture to room temperature, adjust the pH value to neutral with 1 mol / L hydrochloric acid, filter the precipitate, and wash it with deionized water at room temperature to remove impurities.

[0027] The obtained solid is redissolved and recrystallized with ethanol for further purification. The obtained product is dissolved in dodecane to form a 50% solution, and mixed with tributyl phosphate in a volume ratio of 1:1 to obtain the molybdenum extraction agent NP191 for the target alkaline system.

[0028] Example 3

[0029] Preparation of Molybdenum Extraction Agent NP191 Add pyridine with a concentration of 15 mol / L to the reaction vessel, use ethanol as the reaction solvent, heat up to 72 °C. After reaching the reaction temperature, add sulfamic acid with a concentration of 12 mol / L. The volume ratio of pyridine to sulfamic acid is 1.2:1, and stir and react for 8 min.

[0030] Add sodium hydroxide as a promoter. After the sodium hydroxide is completely dissolved, keep the pH value of the system at 11, heat up to 83 °C, and introduce oxygen under the condition of constant temperature stirring, keeping the oxygen partial pressure at 3 MPa during the reaction, and the reaction time is 7 h.

[0031] After the reaction is completed, cool the reaction mixture to room temperature, adjust the pH value to neutral with 0.1 mol / L nitric acid, filter the precipitate, and wash it with deionized water at room temperature to remove impurities.

[0032] The obtained solid is redissolved and recrystallized with ethanol for further purification. The obtained product is dissolved in kerosene to form a 50% solution, and mixed with tributyl phosphate in a volume ratio of 1:1 to obtain the molybdenum extraction agent NP191 for the target alkaline system.

[0033] Example 4

[0034] Application of Molybdenum Extraction Agent NP191 Measure 490 mL of the alkaline leaching solution of copper smelting slag with a molybdenum content of 2 g / L. According to the O / A = 7:1 ratio, add 70 mL of the molybdenum extraction agent NP191 prepared in Example 1. Pour the mixed solution into a separatory funnel, place it in an extraction shaker and react at room temperature for 5 min. Take out the separatory funnel and let it stand until the organic phase and the aqueous phase are separated. Then separate the organic phase and the aqueous phase. According to the O / A = 3:1 ratio, add 23.3 mL of the stripping reagent to the organic phase, place it in an extraction shaker and react at room temperature for 5 min. Take out the separatory funnel and let it stand until the organic phase and the aqueous phase are separated. Then separate the organic phase and the aqueous phase, and take samples for molybdenum content analysis. After extraction treatment, the molybdenum extraction rate reaches more than 99.5%, and the molybdenum concentration is enriched from 2 g / L to 41.81 g / L.

[0035] Table 1 XRF elemental analysis of the solution before extraction of the copper smelting slag leachate (mass fraction %) Table 2 XRF elemental analysis of the solution after extraction of the copper smelting slag leachate (mass fraction %)

Claims

1. A method for preparing a molybdenum extracting agent NP191 for an alkaline system, characterized in that: The steps include: Add 10-15 mol / L pyridine to the reaction vessel, use ethanol as the reaction solvent, raise the temperature to 70-75°C, and after reaching the reaction temperature, add 10-12 mol / L amination reagent, and stir the reaction for 8-12 minutes; Add an alkaline reagent as a promoter. After the alkaline reagent is completely dissolved, heat it to 80-85°C. Under constant temperature stirring conditions, introduce oxygen to maintain an oxygen partial pressure of 2-4 MPa during the reaction. The reaction time is 6-8 hours. After the reaction is completed, the reaction mixture is cooled to room temperature, the pH value is adjusted to neutral with dilute acid, the precipitate is filtered, and then washed to remove impurities; The obtained solid was further purified by secondary dissolution and recrystallization with ethanol. The obtained product was dissolved in a non-polar solvent to form a 50% solution, and mixed with tributyl phosphate in a volume ratio of 1:1 to obtain the target alkaline system molybdenum extractor NP191.

2. The preparation method of molybdenum extracting agent NP191 according to claim 1, characterized in that: The volume ratio of the pyridine to the amination reagent is 1-1.2:

1.

3. The preparation method of molybdenum extracting agent NP191 according to claim 1, characterized in that: After adding the amination reagent, the reaction time is 10 min.

4. The method for preparing the molybdenum extracting agent NP191 according to any one of claims 1 to 3, characterized in that: The amination agent is any one of hydroxylamine, carbamate and aminosulfonic acid.

5. The method for preparing the molybdenum extracting agent NP191 according to claim 1, characterized in that: The amount of the alkaline agent added must ensure that the pH value of the reaction system is 9-12.

6. The method for preparing the molybdenum extracting agent NP191 according to any one of claims 1 or 5, characterized in that: The alkaline reagent is any one of sodium hydroxide, sodium carbonate, sodium bicarbonate and ammonia water.

7. The method for preparing the molybdenum extracting agent NP191 according to claim 1, characterized in that: The dilute acid is any one of 0.1-2 mol / L sulfuric acid, 0.1-1 mol / L hydrochloric acid, and 0.1-1 mol / L nitric acid.

8. The method for preparing the molybdenum extracting agent NP191 according to claim 1, characterized in that: The non-polar solvent is any one of kerosene, n-hexane, cyclohexane, n-dodecane and petroleum ether.

9. The method for preparing the molybdenum extracting agent NP191 according to claim 8, characterized in that: The non-polar solvent is kerosene.

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