Method for recovering rare earth oxide from fluorescent powder and polishing powder waste

Abstract

The invention relates to a method for recovering rare earth oxide from fluorescent powder and polishing powder waste, which comprises the following five steps of: (1) firing the waste by using a self-designed firing kiln; (2) dissolving the rare earth waste in H2SO4, glacial acetic acid and cosolvent mixed solution, returning filter residue, and continuously dissolving; and adding filtrate into a multistage extraction tank for rare earth extraction separation; (3) performing extraction separation by a fuzzy extraction separation and purification technology to obtain single rare earth oxide; (4) adding zinc powder into SmEuGd rare earth chloride solution obtained by separation and performing reduction and extraction and purification to produce fluorescent grade europium oxide; and (5) performing ammonia-free saponification to discharge wastewater without ammonia nitrogen. The wastewater is recovered and used for preparing ammonia-free saponification liquid. By the method, the rare earth fluorescent powder and polishing powder waste is recovered in a low-cost and pollution-free mode.

Description

technical field [0001] The invention relates to the technical field of recycling rare earth resources, in particular to a method for recycling rare earth oxides from fluorescent powder and polishing powder waste. Background technique [0002] Rare earth is an important strategic resource for my country's high-tech industry in international competition. my country is the world's largest rare earth consumer, and due to production and use factors, the current domestic production of phosphors, scrapped products, and rare earth-containing polishing powders generate hundreds of thousands of tons of waste. Rare earth waste slag and waste are valuable renewable resources. Recovering rare earth elements from waste is equivalent to opening a medium-scale rare earth mine every year, which is conducive to resource utilization and environmental protection, and is in line with national industrial policies. [0003] At present, the production process of recovering valuable elements from r...

AI Technical Summary

Problems solved by technology

There are common problems such as low acid dissolution rate of rare earth waste, and the chemical auxiliary materials used in the recovery of rare earth are finally discharged in the form of ammonia and nitrogen wastewater, resulting in the waste of a large number of valuable resources and serious pollution to the environment.

Images