离子型稀土矿镁盐体系开采工艺先进性分析

Analysis on the Advancement of Mining Process of Magnesium Salt System of Ion-Adsorbed-Rare-Earth Ore

摘要: 稀土是不可再生的重要战略资源，需提高开发利用水平，实现绿色开采。针对近几十年来硫酸铵浸出–碳酸氢铵除杂沉淀工艺引发的氨氮污染问题，本文采用硫酸镁浸出–氧化镁富集工艺进行了稀土原地开采试验。试验结果表明，在浸矿剂浓度为1%~3%、注液45日、顶水循环100日、浸出液pH为4~4.5的条件下实现了稀土资源高效浸取，稀土回收率可以达到90%；与铵盐开采体系对比，镁盐体系在水环境、资源回收率、产品质量和经济性方面都具有一定的优势，进一步开展镁盐体系适用性研究对提高离子型稀土开采水平具有重要意义。

Abstract: Rare earth is an important non-renewable strategic resource, which is necessary to improve the level of development and utilization to achieve green mining. In this paper, the in-situ magnesium sulfate leaching-magnesium oxide enrichment process was proposed to conduct rare earth mining, which aims to abate ammonia nitrogen pollution caused by the ammonium sulfate leach-ing-ammonium bicarbonate precipitation and impurity removal process in recent decades. The results show that high leaching efficiency of rare earth resources is achieved. The rare earth re-covery rate reaches 90% under the conditions of leaching agent concentration of 1%~3%, liquid injection for 45 days, top water circulation for 100 days, and leaching solution pH of 4~4.5. The magnesium salt system has certain advantages on water environment, resource recovery rate, product quality, and economy compared with the ammonium salt system. Further research on the applicability of the magnesium salt system is of great significance to improve the level of exploita-tion of ion-adsorbed-rare-earth ore.