Preparation method of transformation agent for SED-MET germanium deposition method

Abstract

The invention discloses a preparation method of a transformation agent for an SED-MET germanium deposition method, and belongs to the technical field of hydrometallurgy. The preparation method comprises the following steps: mixing malic acid and absolute ethyl alcohol according to a volume ratio of 1: (1-10), adding aluminum oxide accounting for 0.1-1% of the mass of the malic acid, and stirring and reacting at 70-100 DEG C for 1-4 hours to generate ethyl malate. And after the reaction is finished, cooling to room temperature, adjusting the pH value of the reaction system to be neutral, extracting the ethyl malate, removing water, filtering, and separating the extracting agent to obtain the target transformation agent. According to the preparation method disclosed by the invention, the mesh number and the optimal loading capacity of aluminum oxide are optimized, the mass transfer resistance is reduced, and the reaction rate and the conversion rate are improved. The temperature and time of esterification reaction are optimized, catalyst deactivation and side reaction are prevented, and reaction energy consumption and product yield are both considered. The preparation method has the advantages of easily available raw materials, simple and convenient production process, good process compatibility, biodegradable and easy recovery of products, environmental protection and cost advantages, and great popularization and application values.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrometallurgy, and particularly relates to a preparation method of a transformation agent for the SED-MET germanium precipitation method. Background Art

[0002] The SED-MET germanium precipitation method includes two stages: selective extraction and metal organic conversion precipitation. At present, the commonly used transformation agents are as follows: acidic transformation agents such as hydrochloric acid, sulfuric acid, etc. When used, the pH value of the system needs to be precisely controlled. If not controlled properly, it will inhibit the precipitation of germanium and may also introduce impurities; oxidizing agents such as hydrogen peroxide, sodium hypochlorite, etc. may over-oxidize other metals when used; reducing agents such as Na 2 SO 3 etc. have the defect of slow reaction rate; basic transformation agents such as NaOH, NH 4 OH, etc. The treatment process is relatively complex, and the pH value of the system needs to be adjusted multiple times, and it may also introduce Na + / NH 4 + impurities. Based on this, the present invention aims to provide a preparation method of a new complex transformation agent with a simplified process flow, high efficiency, convenience, and environmental friendliness, improve the selectivity during germanium precipitation, avoid co-precipitated impurities, and improve the purity of germanium recovery. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method of a transformation agent for the SED-MET germanium precipitation method.

[0004] The purpose of the present invention is achieved as follows: The preparation method of the transformation agent for the SED-MET germanium precipitation method includes the following steps: Mix malic acid and absolute ethanol in a volume ratio of 1:1 to 10, add alumina equivalent to 0.1% to 1% of the mass of malic acid, and stir and react at 70 to 100 °C for 1 to 4 h to generate ethyl malate; After the reaction is completed and cooled to room temperature, adjust the pH value of the reaction system to neutral, extract ethyl malate, remove water, filter, and separate the extractant to obtain the target transformation agent.

[0005] Compared with the prior art, the technical solution of the present invention has the following advantages: The alumina in the technical solution of the present invention provides acidic sites to catalyze the esterification reaction, promote the dehydration condensation of the carboxyl group in malic acid and the hydroxyl group in ethanol to generate ethyl malate; the hydroxyl groups (-OH) and carboxyl groups (-COOH) in the prepared transformation reagent provide oxygen atoms to form stable coordination bonds with germanium ions (Ge 4+ ), realizing the efficient conversion of germanium ions from one form to another under weakly acidic conditions (pH 4 to 6) to generate soluble complexes, which is convenient for subsequent separation and recovery.

[0006] The technical solution of the present invention reduces the mass transfer resistance by optimizing the alumina mesh number and the optimal loading amount, effectively improving the reaction rate and conversion rate. By optimizing the temperature and time of the esterification reaction, the inactivation of the catalyst and the occurrence of side reactions are effectively prevented, taking into account the reaction energy consumption and product yield. In addition, the technical solution of the present invention has easily available raw materials, a simple production process, good process compatibility, and the product ethyl malate is biodegradable and easy to recycle, having both environmental protection and cost advantages, and having great popularization and application value. Detailed implementation manners

[0007] The following further describes the present invention, but does not limit the present invention in any way. Any transformation or substitution based on the teachings of the present invention belongs to the protection scope of the present invention.

[0008] The preparation method of the transformation agent for the SED-MET germanium precipitation method includes the following steps: Mix malic acid and absolute ethanol in a volume ratio of 1:1 to 10, add alumina equivalent to 0.1% to 1% of the mass of malic acid, and stir and react at 70 to 100 °C for 1 to 4 h to generate ethyl malate; After the reaction ends and cools to room temperature, adjust the pH value of the reaction system to neutral, extract ethyl malate, remove water, filter, and separate the extractant to obtain the target transformation agent.

[0009] The volume ratio of the malic acid to the absolute ethanol is preferably 1:3 to 5.

[0010] The alumina is preferably acidic alumina with a pH of 4 to 5.5, and the mesh number of the alumina is 100 to 300 meshes; the alumina is preheated to 55 to 65 °C before being added to the reaction system.

[0011] The temperature of the reaction is preferably 75 to 85 °C.

[0012] The time of the reaction is preferably 2.5 to 3.5 h.

[0013] The pH value of the reaction system is adjusted using a 0.1 to 0.5 mol / L sodium carbonate solution.

[0014] The extraction of ethyl malate refers to extraction with ethyl acetate and then separation of the organic phase.

[0015] The water removal refers to drying the separated organic phase with anhydrous sodium sulfate after extracting ethyl malate.

[0016] The separation of the extractant refers to separating the extractant by vacuum distillation.

[0017] Example 1

[0018] Mix malic acid and absolute ethanol in a volume ratio of 1:1, add acidic alumina equivalent to 0.1% of the mass of malic acid, with a particle size of 300 mesh, stir and react at 70 °C for 4 h to produce ethyl malate. After the reaction is completed and cooled to room temperature, adjust the pH value of the reaction system to 6.5 with 0.1 mol / L sodium carbonate solution, extract ethyl malate with ethyl acetate, separate the organic phase, dry the separated organic phase with anhydrous sodium sulfate, filter, and then separate the extractant by vacuum distillation to obtain the target transformation agent.

[0019] Example 2

[0020] Mix malic acid and absolute ethanol in a volume ratio of 1:3, add acidic alumina equivalent to 0.5% of the mass of malic acid, with a particle size of 200 mesh, stir and react at 75 °C for 3.5 h to produce ethyl malate. After the reaction is completed and cooled to room temperature, adjust the pH value of the reaction system to 7.5 with 0.5 mol / L sodium carbonate solution, extract ethyl malate with ethyl acetate, separate the organic phase, dry the separated organic phase with anhydrous sodium sulfate, filter, and then separate the extractant by vacuum distillation to obtain the target transformation agent.

[0021] Example 3

[0022] Mix malic acid and absolute ethanol in a volume ratio of 1:5, add acidic alumina equivalent to 0.8% of the mass of malic acid, with a particle size of 200 mesh, stir and react at 85 °C for 2.5 h to produce ethyl malate. After the reaction is completed and cooled to room temperature, adjust the pH value of the reaction system to 7.0 with 0.2 mol / L sodium carbonate solution, extract ethyl malate with ethyl acetate, separate the organic phase, dry the separated organic phase with anhydrous sodium sulfate, filter, and then separate the extractant by vacuum distillation to obtain the target transformation agent.

[0023] Example 4

[0024] Mix malic acid and absolute ethanol in a volume ratio of 1:10, add acidic alumina equivalent to 1% of the mass of malic acid, with a particle size of 100 mesh, stir and react at 100 °C for 1 h to produce ethyl malate. After the reaction is completed and cooled to room temperature, adjust the pH value of the reaction system to 7.5 with 0.3 mol / L sodium carbonate solution, extract ethyl malate with ethyl acetate, separate the organic phase, dry the separated organic phase with anhydrous sodium sulfate, filter, and then separate the extractant by vacuum distillation to obtain the target transformation agent.

Claims

1. A method for preparing a transformation agent for SED-MET germanium precipitation method, characterized in that: The steps include: Malic acid and anhydrous ethanol are mixed in a volume ratio of 1:1-10, and aluminum oxide equivalent to 0.1-1% of the mass of malic acid is added, and stirred at 70-100°C for 1-4 hours to generate ethyl malate; After the reaction is completed, the mixture is cooled to room temperature, the pH value of the reaction system is adjusted to neutral, ethyl malate is extracted, water is removed, the mixture is filtered, and the extractant is separated to obtain the target conversion agent.

2. The method for preparing the transformation agent according to claim 1, characterized in that: The volume ratio of malic acid to anhydrous ethanol is 1:3-5.

3. The method for preparing the transformation agent according to claim 1, characterized in that: The alumina is acidic alumina with a pH of 4 to 5.

5.

4. The method for preparing the transformation agent according to claim 1, characterized in that: The reaction temperature is 75-85°C.

5. The method for preparing the transformation agent according to claim 1, characterized in that: The reaction time is 2.5 to 3.5 hours.

6. The method for preparing the transformation agent according to claim 1, characterized in that: The pH value of the reaction system is adjusted using a 0.1-0.5 mol / L sodium carbonate solution.

7. The method for preparing the transformation agent according to claim 1, characterized in that: The extracting of ethyl malate refers to extracting with ethyl acetate and then separating the organic phase.

8. The method for preparing the transformation agent according to claim 1, characterized in that: The dehydration refers to drying the separated organic phase with anhydrous sodium sulfate after extracting ethyl malate.

9. The method for preparing the transformation agent according to claim 1, characterized in that: The separation of the extractant refers to separation of the extractant by a reduced pressure distillation method.