YANG Fan, LI Feng, HU Nan, ZHANG Hui, DING De-xin^*

(1. Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China;
2. Hunan Province Key Laboratory of Green Development Technology for Extremely Low Grade Uranium Resources, Hengyang 421001, China)

Abstract: In order to reveal the process mineralogical characteristics of uraniferous coal ash and to provide a theoretical basis for the research and development of highly efficient hydrometallurgical processing technology for this unconventional uranium resource, the compositions, mineral properties, and uranium inlay characteristics of uraniferous coal ashes have been studied by using means of mineral liberation analyser (MLA) and scanning electron microscope (SEM) in this paper. The results show that the uraniferous coal ash contains main minerals of montmorillonite, quartz, and feldspar, accounting for 83 %, minor mineral of hematite, and uranium minerals of pitchblende, hydrosiliunite, uraninite, uraninite, and thorium silicate (U); The particle sizes of uranium minerals in uraniferous coal ashes are generally lower than 75 μm, while those of other minerals are larger than 75 μm. Uranium minerals are mainly embedded in montmorillonite, quartz, feldspar, and hematite. Their monomer dissociation degree is relatively low. Therefore, in order to high efficiently develop uranium from the uranium-bearing coal ash, the ash should be grinded to smaller than 75 μm in size and a new uranium hydrometallurgical processing method should be developed.

Keywords: Uraniferous coal ash; uranium minerals; dissociation degree; process mineralogy; efficient recover

ACTA MINERALOGICA SINICA Vol. 40, No.6, 2020, page 709-713