Method for recovering rare earth from rare earth secondary resources

Abstract

The invention provides a method for recovering rare earth from rare earth secondary resources. The method comprises the following steps that wastewater deposit is put into a container filled with a sodium hydroxide solution, the wastewater deposit reacts with sodium hydroxide, and separation is carried out to obtain a solid product after the reaction is completed; the solid product is put into anacid decomposition tank filled with acid decomposition residues for acid decomposition reaction and then is leached to obtain a rare earth material liquid; and the rare earth material liquid is introduced into a rare earth separation process. According to the method, the wastewater deposit is subjected to alkali conversion through the sodium hydroxide solution, then hydrochloric acid leaching is carried out through the acid decomposition tank and the acid decomposition residues, and finally, the rare earth material liquid high in rare earth content is obtained; and the rare earth material liquid can return to the rare earth separation and production process for recycling. The rare earth recovery method is simple to operate, practical and effective, has high recovery rate, saves resources,and adds a new economic growth point for enterprises.

Description

technical field [0001] One or more embodiments of this specification relate to the technical field of utilization of secondary rare earth resources, and in particular to a method for recovering rare earths from secondary rare earth resources. Background technique [0002] China is a big country in rare earth smelting, and the distribution of resources presents the characteristics of "heavy in the south and light in the north", that is, the south is dominated by ionic rare earth ores with high content of medium and heavy rare earths, while the northern rare earth ores contain more light rare earths. Usually, the price of medium-heavy rare earths is much higher than that of light rare earths. Therefore, the smelting value of southern ion-type rare earth ores is high, which is generally valued by the industry. [0003] Southern ionic rare earth ores usually use acid decomposition, solvent extraction separation, precipitation and calcination to prepare single rare earth or mixed...

AI Technical Summary

Problems solved by technology

On the one hand, in the acid decomposition process of rare earth ores, in order to reduce the amount of acid used and the leaching rate of impurity elements, the leaching of ore is often carried out in the form of hydrochloric acid, but in the production process, with the continuous consumption of hydrochloric acid, acid leaching The pH of the liquid system continues to rise, and the rare earth ions entering the acid leaching solution are easy to precipitate into the acid decomposition residue, resulting in a high rare earth content in the acid decomposition residue; on the other hand, the rare earth smelting wastewater has complex components, often producing rare earth oxalate or Rare earth particulate matter, usually by introducing wastewater into a pond and standing to obtain rare earth deposits

Whether it is acid decomposition slag or wastewater sediment, the rare earth content is relatively high, and it is an important secondary resource of rare earth produced in the production process of rare earth smelting enterprises. If it is not recycled, it will cause waste of resources. In summary, this application A method for recovering rare earths from rare earth secondary resources is proposed to solve the above-mentioned problems