节点文献
砷化镓废料回收再生研究进展
Research Progress in Recovery and Regeneration of Gallium Arsenide Waste
【摘要】 随着科技的进步与发展,以砷化镓为代表的二代半导体材料已逐渐取代硅材料应用于电子通讯、国防、航空航天等领域。每年在砷化镓晶体制备、设计加工、产品应用环节都会产生大量废料亟待处理。砷化镓废料作为含砷有毒废弃物,蕴藏着品位高、存量大的砷、镓资源,近年来砷化镓废料的清洁、高效回收受到广泛关注。从砷化镓产业链角度出发,总结了上、中、下游产生的砷化镓废料来源与成分间的差异,详细综述了砷化镓晶体切割废料、砷化镓加工废料、废旧砷化镓电子器件这3类砷化镓废料二次资源的回收工艺与现状,归纳了不同方法的技术指标及工艺特点,重点对真空热分解法处理砷化镓废料的相关研究进行了探讨,并展望了砷化镓废料回收技术的未来发展方向。
【Abstract】 With the progress and development of science and technology, the second-generation semiconductor materials represented by gallium arsenide(GaAs) have gradually replaced silicon materials in electronic communications, national defense, aerospace and other fields. Every year, a large amount of GaAs wastes are generated from the crystal growth in upstream, design and processing in midstream and scrap in downstream of the GaAs industry chain. Without in time treatment, the arsenic in GaAs wastes may enter the soil or groundwater with human activities and geological processes, posing a threat to the natural environment and human health. GaAs wastes are one of the main sources of arsenic and gallium resources because of its high grade and large stock. The clean and efficient recycling of GaAs wastes have received wide attention in recent years. This article started from the perspective of the gallium arsenide industry chain, the different recovery processes of GaAs crystal cutting scrap from upstream, GaAs processing wastes from midstream and used GaAs electronic devices were reviewed. The purity of GaAs scrap produced by cutting in the upstream of the industry chain was high, both wet and fire processes could achieve effective separation and recovery of arsenic and gallium. Acid leaching of GaAs cutting scrap, combined with selective precipitation, extraction, resin adsorption and alkaline electrolysis to recover gallium was a relatively mature technology for industrial recovery of GaAs at present. However, a large amount of acidic solution was added in the wet process and the generation of arsenic-containing waste water was inevitable. The processing process and production costs would increase as a result. In contrast, the fire process had shorter processes and simpler operations. But the oxidation roasting method and sulfurization heat treatment method also had the possibility of producing toxic gases containing arsenic. As a new method in recent years, the vacuum decomposition method recovered gallium and arsenic directly in elemental form under vacuum conditions, which had obvious advantages in terms of safety and efficiency, and it was one of the most promising GaAs recovery processes at present. However, the presence of GaAs clusters always affected the recovery rate, and further in-depth study was still needed. GaAs processing process in the middle reaches of the industrial chain such as cutting and grinding generated a large amount of GaAs containing waste water. The composition of waste slag and sludge from GaAs processing waste water by coagulation and sedimentation of iron compounds were complex. Impurities such as mixed iron had a major impact on the subsequent recovery process. Therefore, iron removal became a key issue in the recovery of GaAs processing wastes.Additives with stronger binding ability to Ga3+ were usually selected to extract gallium. Sometimes, arsenic and gallium resources in GaAs processing wastes were also prepared into compound products such as gallium oxide and sodium arsenate crystals. It was beneficial to shorten the waste recovery process, reduce the treatment cost and the discharge of arsenic-containing waste liquid. At the same time, it met the needs of gallium oxide semiconductor, sodium arsenate drugs and other aspects of China. In the downstream of the industry chain, GaAs was encased in organic casings in used electronic devices such as light-emitting diodes(LED), integrated circuits(ICs) and solar cells. The efficient removal of organic matter from used GaAs containing devices, extraction of GaAs and recycling of arsenic and gallium had become a research hotspot for many scholars. The hydrothermal treatment and thermal decomposition were the main methods to remove surface organic matter. The treatment effect of hydrothermal treatment on various used electronic devices was different, which was easy to cause the loss of arsenic. The oxidation of gallium on the surface of GaAs was easily caused by oxygen produced during the thermal decomposition of organic matter. Both of these pretreatment methods to remove organic matter were immature. In summary, the fire process had obvious advantages in recovering GaAs scrap with less impurities. But the industrial recovery of GaAs waste was still dominated by the more selective wet process at present. Based on the huge production and consumption of GaAs in China and the current situation of recycling various types of GaAs wastes, it was believed that there were still challenges in terms of recycling cost, safety, efficiency and product purity. In the future, the development of high performance and low cost extractants and chelating resins for wet process should be focused on. The scale of thermal recovery should be expanded, the arsenic condensation process should be optimized, and the purity of the recovered product should be balanced with the recovery rate. The special equipment for pretreatment of used GaAs electronic devices should be developed and gradually applied in industrial production. The properly combining wet and fire recycling processes to comprehensively improve the recycling efficiency of GaAs wastes. The development of China’s semiconductor wastes recycling industry would be promoted towards high yield and efficiency.
【Key words】 GaAs waste; separation of arsenic and gallium; secondary resources; recycling;
- 【文献出处】 稀有金属 ,Chinese Journal of Rare Metals , 编辑部邮箱 ,2024年12期
- 【分类号】X705
- 【下载频次】18