Method for saponifying P204

Abstract

The invention relates to a method for saponifying P204. The invention belongs to the technical field of saponification and extraction processes in wet process smelting of non-ferrous metals and rare earth, and specifically relates to a method for saponifying a P204 extraction agent. According to the method disclosed by the invention, hexamethylenetetramine is taken as an auxiliary agent, calcium chloride is adopted for directly performing saponification reaction on the P204 at normal temperature, a saponification residual solution is neutralized by using lime and then circulated to a saponification process step for use, and the hexamethylenetetramine and the calcium chloride in the quantity required for reaction are supplemented according to the entrainment loss of filter residues during the lime neutralization process. According to the method disclosed by the invention, the higher and stable saponification rate can be obtained, and the first-stage saponification rate can be above 70%; and the problems of ammonia nitrogen pollution and the like existing in the saponification process for a long time are thoroughly solved, the demands for high-energy consumption products (liquid alkali and ammonia) are reduced, and the method is conductive to environmental production and sustainable development.

Description

technical field [0001] The invention belongs to the technical field of saponification and extraction process in wet smelting of nonferrous metals and rare earths, and specifically relates to a method for saponifying P204 extractant. technical background [0002] At present, the separation of rare earths in my country mainly uses extraction agents such as P204. Before use, the extractant must first be saponified with liquid caustic soda (sodium hydroxide solution) or ammonia water. After saponification, the extractant reacts with the rare earth chloride solution to generate the rare earth-loaded extractant and ammonia (sodium) salt solution, the rare earth-loaded extractant is exchanged and purified by rare earth in a multi-stage extraction device, and then subjected to acid stripping to obtain a water-phase rare earth feed liquid. Saponification of extractant is the core process of saponification extraction technology. At present, the saponification process of extractant m...

AI Technical Summary

Problems solved by technology

After the saponification is completed, the volume of the aqueous phase is too large, which will lead to a large loss of the organic phase discharged with the discarded water

Natural lime raw materials often contain a lot of impurities, such as using milk of lime for saponification, because the impurities cannot be effectively removed, the insoluble impurity elements in the lime will have a negative impact on the extraction process, making it difficult to separate the saponified organic phase, and resulting in a high concentration of impurities Exceeding the standard, affecting product quality

In addition, there are certain difficulties in the measurement of the alkalinity of milk of lime, which is not conducive to the control of the saponification rate of the organic phase in production.

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