Method for recycling gallium from indissolvable gallium compounds and gallium recycled by virtue of method

Abstract

The invention provides a method for recycling gallium from indissolvable gallium compounds and gallium recycled by virtue of the method. The method comprises the steps of mixing waste containing the indissolvable gallium compounds with a chlorinating agent, sintering, leaching a sintered product, and carrying out electrolysis, so as to obtain metal gallium. According to the method, the waste containing the indissolvable gallium compounds is mixed with the chlorinating agent and is sintered, and the difficulty-leached gallium compounds are converted into easily-leached gallium chloride, so thatthe leaching rate of gallium is greatly increased, the recycling rate of gallium reaches 98% or above, and the purity of metal gallium can reach 99.9wt%. The process flow is simple, the consumed timeis relatively short, the waste gas and the dust which are harmful to the environment are not discharged, and the method has wide industrial application prospects.

Description

technical field [0001] The invention belongs to the technical field of recycling semiconductor waste materials, and relates to a method for recovering gallium from waste materials containing insoluble gallium compounds and the gallium obtained by the method. Background technique [0002] Gallium nitride (GaN) is widely used in solid-state light sources, electronic power and microwave radio frequency devices due to its superior properties such as large band gap, high breakdown electric field, high thermal conductivity, high electron saturation drift rate and strong radiation resistance. Wide range of applications, its products cover semiconductor lighting, mobile communications, energy Internet, high-speed rail transit, new energy vehicles and consumer electronics and other fields. With the upgrading of products, the amount of waste slag containing gallium nitride in my country is also increasing rapidly year by year. Since gallium is a scattered metal, the annual output is l...

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Problems solved by technology

Due to the good thermal and chemical stability of gallium nitride, insoluble in inorganic acids such as sulfuric acid and hydrochloric acid, and low-concentration alkalis, there are few studies on the recovery of gallium from waste materials containing gallium nitride, and the existing technologies usually have their own defects. , not conducive to industrial application

[0004] CN 102951618 A discloses a method for recovering germanium, gallium, indium, and selenium from waste diodes. By crushing waste diodes, separating plastic powder and metal powder, oxidizing and roasting the metal powder, adding zinc powder after dissolving the product with acid, Substitution to obtain germanium, gallium, and indium elemental substances, and then roasting the elemental substances in an atmosphere of chlorine or hydrogen chloride, and separating germanium, gallium, and indium elements according to the different condensation temperatures of the chlorination products, but the final product of this method does not obtain metal elemental substances, and consumes The energy is huge, chlorine gas is needed in the recycling process, waste gas and dust are likely to cause environmental pollution, and are not suitable for industrial production

CN 105567982 A discloses a method for recovering gallium metal from gallium nitride waste. Gallium nitride is placed in a reaction vessel, and then sodium hydroxide, hydrogen peroxide, sodium peroxide and other oxidants are added dropwise into the reaction vessel. Until gallium nitride is completely dissolved, finally the reaction solution is passed through electrowinning to recover metal gallium, but this method needs to consume a large amount of oxide and produce a large amount of alkaline solution, and the high concentration of alkaline solution makes separation difficult, which is not conducive to wide application

CN 104532012 A discloses a method for recovering gallium and gold from gallium nitride chip production waste, and CN 104576848 A discloses a method for recovering gallium from waste gallium nitride-based light-emitting diodes, both of which contain nitrogen The particles after crushing gallium chloride waste are separated by high-temperature vacuum metallurgy, and metal elements are recovered. However, this method requires harsh conditions of high temperature and high vacuum, and the waste gas generated needs special treatment before it can be discharged.

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