Concentrating rare earth elements to phosphate in molten coal ash by a temperature gradient approach [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 622.338 *Oil, oil shales, tar sands, natural gas
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Office of the Assistant Secretary of Energy for Fossil Energy ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2021
• Mô tả vật lý: Size: Article No. 103688 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 267690
• Chủ đề: 1. 01 coal, lignite, and peat; 2. Coal ash; 3. Europium; 4. Rare earth elements; 5. Slag

Tóm tắt

Synthetic coal ash bearing 560 ppm europium oxide, blended with aluminum phosphate, was heat treated above its melting temperature and crystal evolutions with respect to europium concentration under controlled cooling were studied. The sample in a boat crucible was subjected to a temperature gradient of 100 �C across it to cause zone refining effects on crystallization behaviors in the melt (slag). Post analysis found six mineral phases formed from the melt while europium was only present in calcium phosphate, implying the majority of europium was segregated to the calcium phosphate. Europium concentrations in the calcium phosphate phase tended to be higher at zones with higher temperatures: as high as 7200 ppm, a 13-fold increase from the initial concentration.