Method for separating and recovering scandium in stable zirconia ceramic wastes containing scandium and rare earth

Abstract

The invention discloses a method for separating and recovering scandium in stable zirconia ceramic wastes containing scandium and rare earth. The method comprises the following steps: crushing ceramic wastes firstly, sieving by virtue of a 200-mesh sieve, then dissolving the crushed powder by acid; after heating and concentrating a filtrate, adding potassium chloride, carrying out crystallization to obtain potassium fluozirconate, and separating zirconium from a solution; and washing filter residues, carrying out conversion treatment by using 5-20 percent sodium hydroxide, washing the residues again after treatment, dissolving with acid, extracting scandium by using an extractant so as to realize the separation of scandium and the rare earth, neutralizing an extraction raffinate with alkali, recovering the rare earth from precipitates, and searing to obtain rare earth oxide; and carrying out washing and back extraction on an organic phase for extracting the scandium, precipitating the scandium by oxalic acid, and searing to obtain scandium oxide. According to the method disclosed by the invention, the purity of Sc2O3 is larger than 99 percent, the recovery rate is larger than 90 percent, the recovery rate of the rare earth is larger than 90 percent, and the recovery rate of Zr is larger than 95 percent.

Description

technical field [0001] The invention relates to a method for separating and recovering scandium from zirconia ceramic waste containing scandium and rare earth stabilized. Background technique [0002] Rare earth-containing, especially scandium-containing stable zirconia ceramics have functions such as high hardness, electrical conductivity, and oxygen transport. They are widely used in solid fuel cells, oxygen sensors, artificial gemstones, etc., and recover valuable elements scandium, Rare earth and zirconium can realize the recovery of secondary resources, achieve the purpose of energy saving, emission reduction and recycling, which is in line with the national industrial policy of sustainable development. my country imports a large amount of zircon sand every year, reaching 800,000 tons per year, and has become the world's largest manufacturer of zirconium compounds. Waste of artificial gemstones (including ZrO 2 and Y 2 o 3 ) There are 400-600 tons of waste per year,...

AI Technical Summary

Problems solved by technology

[0003] At present, the domestic method of recovering rare earth zirconium from waste zirconium ceramic materials containing rare earth mainly adopts alkali fusion method, such as CN201410205377.0, CN201210143905.5, CN200810073501.7 , patent, through two-stage eutectic sintering, then washed with water, acid-dissolved, high-temperature reaction in the process, large energy consumption, distributed precipitation, incomplete separation of zirconium and rare earth, and low purity of recovered products

In CN201310494964.1, hydrochloric acid + sulfuric acid + borate is used for dissolution. Although there is recovery of scandium, the process is dissolved at a high temperature of 200-230°C, and multi-stage precipitation involves many steps and various reagents. The separation yield and purity are not high , the process is long, the purity of recovered scandium and zirconium is not high, and the high-temperature process consumes a lot of energy

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