Separation and utilization method of NdFeB waste

Abstract

The invention provides a method for separating and utilizing neodymium iron boron waste materials. The method comprises the following sequential steps of dissolution with hydrochloric acid, primary solid-liquid separation, precipitation with oxalic acid, secondary solid-liquid separation, hydrolysis process, third solid-liquid separation, acidic oxidation process, precipitation of ferric phosphate, fourth solid-liquid separation, evaporation and concentration, and fifth solid-liquid separation. Iron oxide red and praseodymium oxide are obtained through the steps of dissolution with hydrochloric acid, primary solid-liquid separation, precipitation with oxalic acid and secondary solid-liquid separation; iron oxide red and ferric phosphate precipitate are obtained through the steps of dissolution with hydrochloric acid, primary solid-liquid separation, precipitation with oxalic acid, secondary solid-liquid separation, hydrolysis process, third solid-liquid separation, acidic oxidation process, precipitation of ferric phosphate and fourth solid-liquid separation; ammonium chloride is obtained through the steps of dissolution with hydrochloric acid, primary solid-liquid separation, precipitation with oxalic acid, secondary solid-liquid separation, hydrolysis process, third solid-liquid separation, acidic oxidation process, precipitation of ferric phosphate, fourth solid-liquid separation, the evaporation and concentration and fifth solid-liquid separation. The method is high in recovery rate and purity, environment-friendly and pollution-free, low in recovery cost and the like.

Description

technical field [0001] The invention belongs to the technical field of recovery and reuse of rare earth resources, in particular to a method for separating and utilizing NdFeB waste. Background technique [0002] NdFeB is an alloy of rare earth elements neodymium, praseodymium, praseodymium, etc. and iron oxide. It is a permanent magnet material with high remanence, high coercive force, and high magnetic energy product. It has been widely used in modern industry and electronic technology. . In the process of producing NdFeB permanent magnet components, due to the different shapes and sizes of various components, the blank NdFeB needs to be finely treated by cutting, cutting, grinding, etc. During this finishing process, processing will inevitably occur. Waste, according to statistics, NdFeB waste accounts for about 20% of the total billet, which is a huge amount of NdFeB waste for the huge demand for NdFeB. [0003] Since the composition of NdFeB waste is basically the sam...

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Problems solved by technology

The existing problems are: 1. High resource consumption and low recovery rate greatly increase the cost of separation and recovery, which is extremely impractical; 2. The quality of rare earth elements obtained by separation and recovery is low, and industrial reuse will affect the finished NdFeB The performance and quality of permanent magnet materials; 3. The separation and utilization measures are incomplete, only rare earth elements are separated and extracted, and other substances contained in NdFeB waste, such as metal compounds (iron oxide red, iron phosphate), ammonium chloride, etc., are no longer Separation, extraction, and direct discharge not only cause serious environmental pollution, but also further increase the cost of separation and recovery of rare earth elements

[0005] In view of the problems existing in the separation and utilization technology of traditional NdFeB waste materials, in recent years, various novel and unique separation and recovery technologies have emerged in the industry. The emergence of technologies with the same or similar content

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