南华大学学报（自然科学版）2023，Vol.37Issue(5)：20-27,8.DOI:10.19431/j.cnki.1673-0062.2023.05.004
CO2和O2共注入下方解石溶解对黄铁矿氧化固铀的影响
Effect of Calcite Dissolution on Uranium Fixation by Pyrite Oxidation Under CO2 and O2 Co-injection Conditions
摘要
Abstract
Pyrite and calcite are closely associated with uranium minerals in large in-situ leachablesandstone-type uranium deposits in China.The co-injection of O2 and CO2 in the process of neutral in-situ leaching of uranium will induce pyrite oxidation and calcite disso-lution.At present,the effect of calcite dissolution on pyrite oxidation and uranium fixation in the coexistence system of the two is not clear.In this paper,the effect of calcite disso-lution on uranium fixation by pyrite oxidation under CO2 and O2 conditions was compara-tively studied by static batch experiments and numerical simulations.The results showed that the adsorption rate of U(VI)by pyrite oxidation in neutral Tris buffer system without CO2 partial pressure was as high as 90%.The fixation rate of uranium in the uranyl car-bonate system was significantly reduced under CO2 partial pressure,and about 32%of uranium was adsorbed.In the coexistence system of calcite and pyrite,the removal rate of uranium was 27%under the condition of O2 alone,and the removal rate of uranium by py-rite oxidation was only 2%when CO2 and O2 are combined.The numerical simulation re-sults showed that Ca2(UO2)(CO3)3 accounted for 80%and 95%of the O2+pyrite+calcite and CO2+O2+pyrite+calcite systems,respectively.X-ray diffraction(XRD),X-ray photo-electron spectroscopy(XPS)and Fourier transform infrared(FT-IR)results showed that the formation of goethite and lepidocrocite on the surface of pyrite increased the adsorption of U(VI).The dissolution of calcite promoted the formation of Ca-UO2-CO3 complex,which affected the fixation of U(VI)by pyrite and its oxidation products and improved the migration ability of U(VI).关键词
黄铁矿氧化/方解石溶解/CO2+O2/U(VI)赋存形态/U(VI)浸出质量浓度Key words
pyriteoxidation/dissolution of calcite/CO2 +O2/U(VI)speciation/U(VI)leaching concentration分类
能源科技引用本文复制引用
王晶,王赛男,彭国建,张德,雷波,吕俊文,房琦..CO2和O2共注入下方解石溶解对黄铁矿氧化固铀的影响[J].南华大学学报（自然科学版）,2023,37(5):20-27,8.基金项目
国家自然科学基金资助项目(11705082 （）
51874180 （）
51704169) （）
湖南省自然科学基金资助项目(2018JJ3434) （2018JJ3434）
湖南省教育厅科研资助项目(22A0303) （22A0303）
