Improved Extraction Method

For the separation and extraction of tungsten, the common methods include solvent extraction, precipitation, ion exchange, activated carbon adsorption and so on. Overall evaluation shows that in the existing technology of separation of tungsten, there are many shortcomings, such as low separation efficiency, complex process, environmental pollution and so on. How to break through the existing technology and improve separation efficiency is the problem that scientific and technological personnel need to solve.

The traditional solvent extraction method uses poisonous and harmful, inflammable and explosive organic solvents which are harmful to the ecological environment, and its extraction efficiency is not high, and its application space is becoming smaller and smaller. However, recently, some scholars have improved the extraction method, which not only improves the efficiency, but also basically eliminates the hidden dangers of environmental pollution. The methods include the following steps:

(1)Non-ionic surfactant RPE2520, tungsten (VI) aqueous solution, sodium chloride aqueous solution and deionized water were mixed and stirred evenly to obtain mixed solution 1. The concentration of non-ionic surfactant RPE2520 in mixed solution 1 was 50g/L, the concentration of tungsten (VI) was 1g/L, and the concentration of sodium chloride was 300g/L.

(2)Use hydrochloric acid to adjust step (1) mixed solution 1 pH value is 1, get mixed solution 2;

(3)Put the mixed solution 2 of step (2) into a constant temperature magnetic stirrer and stir it. Set the temperature to 25 ℃ and stirring time to 60 min. After stirring, put it in a constant temperature water bath pot to separate the phases statically. The phase separation time is 20 min. A two-phase system with tungsten (VI) as the upper phase and water phase as the lower phase is obtained. The tungsten (VI) concentration in tungsten ion (VI) phase is 2g/L.

(4)The mixed solution 3 was obtained by mixing the non-ionic surfactant phase solution loaded with tungsten (VI) with the aqueous solution of ammonium sulfate; the pH value of the mixed solution 3 was adjusted by ammonia water to 7; the concentration of ammonium sulfate in the mixed solution 3 was 10g/L, the temperature of back-extraction was 25 ℃, the time of phase separation was 10min, the time of phase separation was 60min, and the time of phase separation was loaded with tungsten (VI). The non-ionic surfactant phase (O) is 3 compared with the ammonium sulfate aqueous solution (A). After treatment, the extraction rate of tungsten (VI) is over 92.68%, and the extraction rate of tungsten (VI) is over 93.16%.

Compared with the traditional method, the improved method has the advantages of fast extraction rate, good phase separation, no third phase formation and no emulsification, high extraction efficiency and complete phase separation in aqueous two-phase system. The extraction rate of tungsten (VI) is more than 92%, and the extraction rate of tungsten (VI) is more than 92%. It is a green separation technology, non-toxic and harmless to the environment.

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