Method for preparing rare earth permanent magnetic material with gadolinium by adding nanometer metal powder into magnetic steel waste

Abstract

The invention discloses a method for preparing a rare earth permanent magnetic material with gadolinium by adding nanometer metal powder into magnetic steel waste. The method comprises the steps that collected waste magnetic steel are presorted according to the batch, type and rare earth elements to obtain a pretreated magnet material; the obtained pretreated magnet material and the prepared nanometer metal powder are placed into a common electrolytic furnace to be smelted into molten alloy liquid, and the molten alloy liquid is cast and cooled to be an alloy ingot; the alloy ingot is subjected to hydrogen decrepition and jet milling to be smashed into fine powder, and the fine powder is subjected to static pressing, sintering and two-step heat treatment to obtain a rare earth permanent magnetic material blank with gadolinium; finally, machining, cutting and fine grinding are carried out according to actual requirements, and therefore the rare earth permanent magnetic material with gadolinium is obtained. The fluorescent lifetime of the rare earth permanent magnetic material with gadolinium is effectively prolonged by adding the nanometer metal powder, and the permanent magnetic material has the high activating agent critical concentration; by means of presorting, waste magnetic steel recovery time can be saved, and the extraction technological steps are simplified.

Description

technical field [0001] The invention relates to the technical field of rare earth permanent magnet materials, in particular to a method for preparing rare earth permanent magnet materials containing gadolinium by adding nanometer metal powder to magnetic steel waste. Background technique [0002] Due to the high brittleness of NdFeB magnet materials and miscellaneous specifications, problems such as missing corners and poor dimensions are prone to occur during the electroplating process; thus resulting in a very large amount of scrapped NdFeB magnets after electroplating, and due to other special requirements of customers. Lead to bad scrap phenomenon. The current recycling and reuse process for waste magnets is as follows: all the collected waste magnets are mixed together without pre-sorting, and returned to the recycling container in a unified way, and all the waste magnets contained in the waste magnets are collected in the recycling container. The rare earth elements a...

AI Technical Summary

Problems solved by technology

Although this process method reuses the waste magnetic steel, its extraction process is complicated, and various process parameters of the recovery container need to be adjusted according to the melting point of different rare earth elements to meet the extraction process requirements of different rare earth elements. The equipment puts forward higher requirements

[0003] At the same time, when processing again, a single rare earth metal oxide will be recovered, and the permanent magnet material required to be prepared will be obtained after various processes such as proportioning smelting, and the permanent magnet produced by this process has many defects. The production process is difficult to control, and there are many human factors, which will affect the quality of mass production

Taking NdFeB as an example, the praseodymium, neodymium, iron, boron and other components separated by extraction are mixed and then added to a vacuum melting furnace for melting, and alloy ingots are obtained after melting. Affected by factors such as the uniformity of the previous mixing and the control of the time interval and amount of artificial addition, it will inevitably cause segregation of the alloy ingot material after smelting, and even affect the performance of the alloy ingot material and the effect of the subsequent process. The technical requirements for personnel are high, and the labor intensity is high; in addition, the permanent magnet materials produced by the existing production process have poor thermal stability, which leads to weak magnetic properties of the permanent magnet materials when the external temperature changes greatly, which limits its development and main factors of application