摘要
Abstract
Aiming at the problems of complex uranium occurrence state,high silicon con-tent,large acid consumption and low recovery rate of traditional processes in a typical deep low-grade zirconium-bearing uranium ore in China,the process of"high-gradient magnetic separation,followed by an acid-conditioned ripening step and enhanced leaching"was studied,achieving efficient pre-enrichment and leaching of uranium.X-ray diffraction(XRD)and electron probe microanalysis(EPMA),used to characterize the mineralogical distribution,revealed that uranium primarily occurs as titanium-uraninite,pitchblende(UO2),molybdite-associated uraninite phases or isomorphic substitution min-erals within silicate lattices—all of which are intimately hosted within or substitutionally incorporated into silica-rich host minerals.Pitchblende ore,Using a high-gradient dry magnetic separator under conditions where the grinding fineness was-0.074 mm(ac-counting for 85%of particles)and with a magnetic field intensity ranging from 1.06 to 1.20 T,uranium,thorium,zirconium,and other valuable elements were selectively pre-concentrated,resulting in an enrichment factor exceeding X-fold and the uranium grade in-creased from 0.055%to 0.071%.Meanwhile,the SiO2 content decreased from 52.35%to 32.15%,thereby laying the foundation for subsequent reduction in acid consumption.During the ripening-leaching stage,CaF2 and MnO2 were added as additives and reacted at(120±3)℃for2 hours.The uranium leaching rate increased to80%,the amount of sili-ca gel produced decreased by more than 85%,and the unit consumption of sulfuric acid has decreased to 18.1 kg/t.This process system features strong adaptability,high recovery rate and excellent impurity control,providing a new technical approach for the ef-ficient extraction of complex uranium ore resources.关键词
高梯度磁选/拌酸熟化/强化酸浸Key words
high-gradient magnetic separation/acid-mixing curing/enhanced acid leaching分类
能源科技
