Recycling method of organic phase used for extracting scandium

Abstract

The invention relates to a recycling method of an organic phase used for extracting scandium. The method comprises the following steps of: adding a sodium sulfide solution into the organic phase and mixing; performing phase splitting; discharging a water phase; adding a sulfuric acid solution into the rest of organic phase; washing the acidified organic phase with water; and using the acidified organic phase to extract scandium. The organic phase treated by using the method can be recycled, the subsequent efficiencies of titanium washing and reverse extraction processes also can be improved, most of titanium impurities can be washed off from the organic phase, and the efficiency of reverse extraction can be obviously improved; and the organic phase can be totally reversely extracted by using 3mol / L of industrial alkali, the phase splitting efficiency is rapid, and the scandium content of an obtained alkali cake is high.

Description

technical field [0001] The present invention relates to a recycling method of processing aids, in particular to a recycling method of organic phase used for extracting scandium from titanium dioxide hydrolysis mother liquor. Background technique [0002] In the existing technology, the organic phase containing the extraction agent P204 is usually used to recover scandium from the titanium dioxide waste water, and the organic phase containing scandium directly enters the following operation, for example, after the operations such as titanium washing, back extraction, and pressure filtration, the scandium is recovered. When the organic phase is used to extract scandium from the titanium dioxide hydrolysis mother liquor, while the scandium is extracted, other impurities, such as nickel ion, lead ion, zinc ion, copper ion, etc., are also extracted into the organic phase, but the use of sodium hydroxide or other When the solution is stripped, the impurities are not easily strippe...

AI Technical Summary

Problems solved by technology

When using the organic phase to extract scandium from the titanium white hydrolysis mother liquor, while scandium is extracted, other impurities such as nickel ions, lead ions, zinc ions, copper ions, etc. are also extracted into the organic phase, but with sodium hydroxide or other When the solution is stripped, the impurities are not easy to be stripped out. Over time, these impurities are more and more enriched in the organic phase, and these impurity ions occupy the positions in the organic molecules, which leads to a great reduction in the extraction efficiency of the organic phase and cannot be used continuously. Specifically The performance is that the extraction rate of scandium is reduced, the subsequent process of complexing titanium with sulfuric acid and hydrogen peroxide is difficult to operate, and it is difficult to wash off titanium and other impurities. During stripping, a high concentration of industrial alkali is required to barely strip it out, but the obtained stripping The content of scandium in the extract is low, and the fresh organic phase needs to be replaced frequently in industrial production to effectively extract scandium from the titanium dioxide hydrolysis mother liquor

This will inevitably cause waste of the organic phase and increase production costs.

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