Method for recovering waste hydrogen storage alloy powders

Abstract

The invention discloses a method for recovering waste hydrogen storage alloy powders. The method sequentially comprises the following steps: (1) carrying out particle size classification on the wastehydrogen storage alloy powders; (2) tabletting powders with different particle sizes; (3) loading different kinds of tablets and new materials into a furnace; and (4) carrying out smelting and casting. The preparation method is simple, the process is easy to control, the waste hydrogen storage alloy powders with different particle sizes are respectively pressed into tablets in the smelting processand then layered with the different rare earth alloy new materials in the induction smelting furnace, staged smelting is carried out, the induction effect is good during electromagnetic induction heating, the smelting is fast, environment friendliness is achieved, the energy is saved, the slagging is low, and the yield is high.

Description

Technical field [0001] The invention belongs to the field of hydrogen storage alloy waste recycling and relates to a method for recycling waste hydrogen storage alloy powder. Background technique [0002] At present, the production of rare earth hydrogen storage alloys will produce many alloy powders that cannot meet the requirements for use. For example, a certain amount of waste hydrogen storage alloy powders will be generated during the smelting process and alloy transfer during the production process, especially hydrogen storage alloys in the production process. During the powder process (the ultra-fine powder will be separated and collected in the filter element during the jet mill sorting process), some ultra-fine powder will also be produced; these unusable powders are usually treated as hazardous waste because they contain rare earth metals. In the process of storage in the plant area, it is not only necessary to meet the requirements for temporary storage of environmenta...

AI Technical Summary

Problems solved by technology

However, in the smelting process of hydrogen storage alloys, the particle size of the incoming material and the smelting process have a great influence on the quality of the smelted alloy. This is mainly because the smaller the raw material particles are, the worse the magnetic permeability between the particles is, resulting in electromagnetic induction. The generated eddy current is small, which eventually leads to poor heating effect of the charge, which not only affects the final smelting effect, prolongs the smelting cycle, but even affects the uniformity and composition of the smelted alloy

In addition, the smaller the particles of the incoming charge, the more impurities will be brought in, which will have a negative impact on the purity and content of the final smelted alloy

Hydrogen storage alloy powder can be reused by using vacuum induction furnace to recover and remelt waste hydrogen storage alloy powder, but there are the following problems in the remelting process: firstly, when the powder is evacuated in the vacuum induction melting furnace, it is easy to draw the hydrogen storage alloy powder into In the vacuum pump, it will cause damage to the equipment, reduce the efficiency and effect of vacuuming, and affect the melting process; secondly, because the hydrogen storage alloy powder is easily oxidized, the magnetic permeability and electrical conductivity between the particles are poor. The induction effect of electromagnetic induction heating is poor, and it needs high power and long time heating to melt, so the power consumption is huge, the melting cycle is prolonged, and the cost of the enterprise is expensive and uneconomical. At the same time, due to the large specific surface area of ​​the hydrogen storage alloy powder, its Contact with air before smelting into the furnace will absorb more gas impurities, resulting in large slagging and low product yield in the process of intermediate frequency induction smelting

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