稀土精矿冶炼过程放射性元素迁移分布规律

Migration and Distribution of Radioactive Elements in Rare Earth Smelting Process

中国稀土资源储量巨大,但多为天然放射性核素伴生矿,放射性污染问题一直以来都是关注的焦点。随着稀土矿石的开发利用,这些放射性核素随之迁移,扩散,重新分布和富集,并随着稀土矿冶炼过程产生的三废进入到环境中,处理不当就会成为严重的环境污染问题,也会造成资源的浪费。放射性核素是核能发展中的重要元素,为了更好地利用处置放射性核素,应该清楚这些核素的迁移、分布和富集过程和规律。通过实地调研,考察和查阅大量文献,总结出几大稀土矿主流冶炼工艺过程中放射性元素的迁移分布规律和富集过程。结果表明:几大稀土矿虽然冶炼工艺不同,但其中放射性元素90%左右迁移、富集到冶炼废渣中,剩余少部分分布到废水、废气及产品中。因此,需要加大稀土矿冶炼新工艺的研究及现行工艺的技术改造,从源头解决放射性废渣的污染和堆存问题;研究开发现存的冶炼废渣中稀土、钍(铀)等有价元素回收利用工艺,实现废渣减量化、资源化和无害化。

The rare earth resources in China are huge,but most of them are associated with natural radionuclides.The issue of radioactive pollution has always been the focus of attention.With the development and utilization of rare earth,the radionuclides migrate,diffuse,redistribute and enrich,and then enter the environment as the wastes generated in the smelting process of rare earth,which will become a serious environmental pollution problem and also cause a waste of resources.Radionuclides are important elements in the development of nuclear energy.In order to make better use of radionuclides,the migration,distribution and enrichment of these radionuclides should be clear.Through investigations and inspections,the migration,distribution and enrichment rules of radioactive elements in the smelting process of several major rare earth are summarized.The results show that although the smelting processes of several major rare earth mines are different,about 90%of the radioactive elements migrate and concentrate in the waste residue,and the remaining small part are distributed in waste water,waste gas and products.Therefore,it is necessary to further study rare earth smelting process and transform the current process.This can solve the pollution problems of radioactive waste from the source;Researching and developing the recycling process of valuable elements such as rare earth and thorium(uranium)in the smelting waste residue can achieve waste residue reduction,resource utilization and harmlessness.