Method for comprehensive recovery and utilization of fluorine-containing alkali waste water and saponification of extracting agent

Abstract

The invention relates to a waste fluoride-containing alkaline water processing method during the rare earth hydrometallurgy production process. The processing method can also achieve the purpose of the extractant saponification. After mixed with the organic phase, the waste fluoride-containing alkaline water generated during the rare earth hydrometallurgy production process undergoes saponification; the saponified organic phase is mixed with the solution waiting for extraction, and then the extraction separation and reextraction are conducted; the saponified water phase is used for the NaF or cryolite preparation. The invention has the advantages that by using the available and cheap waste alkaline water as the raw material, the saponification cost is reduced during the extraction separation; the fluorine ion in the wastewater can be recycled so as to reduce the environment pollution and save a lot of the three wastes processing cost.

Description

technical field [0001] The invention belongs to the field of metallurgy and chemical industry, and in particular relates to a treatment method for fluorine-containing waste alkaline water in the rare earth hydrometallurgy process. Specifically, it relates to a method for comprehensive recovery and utilization of fluorine-containing waste alkaline water and saponification of extractant. Background technique [0002] Bastnaesite is a rare earth resource dominated by light rare earths, and its development and application are crucial to the application of rare earths. [0003] For the smelting method of bastnaesite, the hydrochloric acid decomposition process is the most widely used at present, and the sulfuric acid method is rarely used. Many literature reports on the hydrochloric acid method can be roughly divided into the following two types. A kind of is first alkali transfer and then acid dissolution, as the method disclosed in the Chinese invention patent CN1205363A is t...

AI Technical Summary

Problems solved by technology

The second method is acid dissolution first and then alkali conversion, such as the method in the Chinese invention patent with the publication number CN1683569 A, which is to dissolve bastnaesite with hydrochloric acid after oxidation and roasting, and the insoluble part is converted by alkali, and then washed with water to remove fluorine. The re-acid-dissolving method can obtain cerium-less lanthanum-rich feed liquid and cerium oxide products with a purity of more than 95% respectively by controlling the dissolving conditions of hydrochloric acid; the method in the Chinese invention patent with the publication number CN1240759 is also alkali conversion after dissolving hydrochloric acid, and washing with water to remove fluorine , but the conditions are simple, and finally only a primary product of mixed rare earth chloride is obtained

Existing methods generally can only deal with OH alone - or F - , it is difficult to effectively control these two ions at the same time, resulting in serious pollution