黄磷电尘灰真空碳热还原法提镓

Extraction of Gallium from Yellow Phosphorus Flue Dust by Vacuum Carbothermal Reduction

黄磷电尘灰是黄磷生产过程中产生的一种含镓固体废弃物,其高值化综合利用对于缓解该行业产生的生态污染意义重大。采用真空碳热还原法对黄磷电尘灰中稀有金属镓进行回收,对各组分化学反应开展系统的热力学计算和饱和蒸汽压的研究,明确各物质在真空条件的逸出分离行为。结果表明,在碳热还原反应压力10 Pa、反应温度1373 K时,能够有效促进镓、铅、锌等有价金属的挥发回收;通过对冷凝产物采用扫描电镜分析,发现真空状态相对常压状态出现了镓富集区,且该区域中镓含量为原料的30~40倍。研究结果可为黄磷电尘灰真空碳热还原法提镓提供一定的理论基础与参考。

Yellow phosphorus flue dust is a kind of gallium-containing solid waste produced in the production of yellow phosphorus.The high value comprehensive utilization for the dust is significant to alleviate the ecological pollution produced in this phosphorus industry.In this paper,the rare metal Ga in yellow phosphorus flue dust was recycled by vacuum carbothermic reduction method.The thermodynamic calculation and saturated vapor pressure study of chemical reaction of each component were carried out,and the escape and separation of each substance in vacuum was clarified.The results show that under the reaction pressure of 10 Pa and the reaction temperature of 1373 K conditions,the volatilization recovery of valuable metals including Ga,Zn and Pb can be effectively promoted.Through the scanning electron microscopy(SEM)analysis of condensed products,it was found that the Ga rich region appeared in the vacuum state compared with the normal pressure state.The Ga content in this area was 30 to 40 times more than that in raw materials.This study provides some theoretical basis and reference significance for Ga extraction by vacuum carbothermal reduction of yellow phosphorus flue dust.