论文部分内容阅读
稀土元素的开采和处理通常会给环境带来严重的影响。稀土元素除了富集度很低以外,许多矿床含有高浓度的放射性元素(如铀和钍),需要对其进行分离和处理。采矿和处理过程对土地的占用也非常严重,尾矿坝、放射性废料的长期堆放同样占用土地。另外,在生产过程中,提取、分离和精炼过程需要消耗大量的水、酸性物质和电能;尤其是在离子交换、分离结晶和萃取过程中消耗得更多。
Rare earth elements mining and processing usually have a serious environmental impact. In addition to the low abundance of rare earth elements, many deposits contain high levels of radioactive elements (such as uranium and thorium) that need to be separated and disposed of. The occupation of land by mining and handling processes is also very serious. Tailings dam and radioactive waste also occupy land for a long time. In addition, extraction, separation and refining processes consume large amounts of water, acids and electricity during the production process; more particularly during ion exchange, fractional crystallization and extraction.