Technique for producing 99% praseodymium-neodymium oxides by using Nd-Fe-B smelting slag

Abstract

The invention relates to a production process of extracting Pr-Nd oxide by utilizing NdFB to smelt waste slag and magnetic slurry. The invention is characterized in that: according to chemical characteristics of rare metal ion, the valuable elements are separated and extracted by acid leaching, ammonium bicarbonate sedimentation, selective dissolution, oxalate sedimentation, and burning procedures, so as to produce high purity Pr-Nd oxide. The invention has the advantages of high purity (reaching 99%), high utilization ratio of raw materials (reaching 98%), simple process (two dissolutions and two sedimentations, and then burning are performed to obtain high purity products), no solid waste slag for polluting environment, and being suitable for large-scale production.

Description

technical field [0001] The invention relates to a production process for extracting praseodymium and neodymium oxides from NdFeB smelting waste slag and waste magnetic mud. Background technique [0002] NdPr magnetic materials are one of the important basic materials supporting the modern electronic information industry, and are closely related to people's lives. With the popularity of communication equipment such as computers, mobile phones, and car phones, and the rapid development of energy-saving cars, the world's demand for high-performance rare earth permanent magnet materials has grown rapidly. At present, during the smelting process of NdFeB, there will be waste residues and sludges, which contain a considerable amount of praseodymium and neodymium compounds. If they are not recycled, it will not only waste resources but also pollute the environment. The original recycling generally adopts rough processes such as washing and calcination, which have a low recovery ra...

AI Technical Summary

Problems solved by technology

At present, waste residue and waste sludge will be produced in the process of NdFeB smelting. These waste residues and waste sludge contain a considerable amount of praseodymium and neodymium compounds. If they are not recycled, they will waste resources and pollute the environment.

The original recycling generally adopts rough processes such as washing and calcination, and its recovery rate is low and the secondary pollution is heavy, even exceeding the degree of direct waste pollution.

At present, there are also recovery processes such as double salt precipitation and alkali conversion, as well as recovery processes such as sulfuric acid dissolution, double salt precipitation, alkali conversion and hydrochloric acid dissolution, extraction and separation. Both of them have low metal recovery rate and large consumption of chemical materials. , high cost, and many wastes in the process, and other processes such as fine grinding and crushing of waste materials, oxidation roasting, excellent dissolution of hydrochloric acid, neutralization and removal of impurities, double salt precipitation of iron, and extraction and separation. The disadvantage is that it requires multiple Calcination, precipitation, dissolution, and kerosene extraction have greatly increased the overall cost of the product, and the purity of the final product is also low

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