Process of comprehensively recovering rare earth from electrolytic fused salt waste residues of rare earth

Abstract

The invention relates to a process of comprehensively recovering rare earth from electrolytic fused salt waste residues of rare earth and relates to the technical field of rare earth preparation. Theprocess comprises the following steps: S1, raw material classification: classifying to-be-recovered electrolytic fused salt residues according to different contents of impurities and total amounts ofrare earth; S2, raw material crushing: roughly and intermediately crushing the raw materials classified in the S1, and then grinding the intermediately crushed raw materials by a ball mill till the granularity is greater than 130 meshes to prepare powder I; and S3, proportioning: proportioning the powder prepared in the S2 and sodium hydroxide in a weight ratio of 1: 0.27, and mixing the mixture for 10-15 min in a material mixer fully and uniformly to prepare powder II. The process of comprehensively recovering rare earth from electrolytic fused salt waste residues of rare earth is simple to operate, low in cost and environmental-friendly. Fluorides added for part of common fused salt electrolysis can be obtained by the process. The fluorides processed by a dry method or a wet method are reduced, hydrogen fluoride pollution is reduced, the fluorinating energy consumption is saved and the process is energy-saving and environmental-friendly.

Description

technical field [0001] The invention relates to the technical field of rare earth preparation technology, in particular to a rare earth electrolytic molten salt waste slag comprehensive recovery rare earth technology. Background technique [0002] Rare earth elements have been widely used in electronics, petrochemical, metallurgy, machinery, energy, light industry, environmental protection, agriculture and other fields. At present, the main methods of rare earth metal smelting are metallothermic reduction and molten salt electrolysis. Common rare earth metals such as La, Ce, Pr, Nd, Gd, Ho and rare earth alloys such as Pr-Nd, Nd-Fe, Dy-Fe are all produced by fluoride system molten salt electrolysis process. The total yield of rare earth electrolytic molten salt electrolysis is about 92%, and most of the rare earth loss is in the waste molten salt. It is estimated that more than 5% of the waste molten salt produced in the process of molten salt electrolysis is about 5%. The...

AI Technical Summary

Problems solved by technology

At present, the traditional concentrated sulfuric acid roasting method and sodium hydroxide method are used in the treatment process of rare earth molten salt slag. This process not only consumes high energy and costs, but also produces waste gas containing hydrogen fluoride and sulfur dioxide, which has a certain impact on the environment. , and the purification and treatment measures of waste gas are complicated, and it is difficult to meet the environmental protection requirements