| 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,(5):20~27.[WANG Jing,WANG Sainan,PENG Guojian,ZHANG De,LEI Bo,Lü Junwen,FANG Qi.Effect of Calcite Dissolution on Uranium Fixation by Pyrite Oxidation Under CO2 and O2 Co-injection Conditions[J].Journal of University of South China(Science and Technology),2023,(5):20~27.] |
| 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 |
| 投稿时间：2023-04-05 |
| DOI：10.19431/j.cnki. 1673-0062.2023.05.004 |
| 中文关键词: 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〖PS23-05王晶OSID码.tif Y4*4,Y#〗 |
| 英文关键词:pyriteoxidation dissolution of calcite CO2+O2 U(VI)speciation U(VI)leaching concentration |
| 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);湖南省教育厅科研资助项目(22A0303) |
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| 中文摘要: |
| 我国大型可地浸砂岩型铀矿床普遍存在黄铁矿和方解石与铀矿物密切共生现象。中性地浸采铀过程中O2和CO2的共注入会诱导黄铁矿氧化和方解石溶解,目前针对二者共存体系中方解石溶解对黄铁矿氧化固铀的影响尚不明确。本文通过静态批实验和数值模拟的方法对比研究了CO2和O2条件下方解石溶解对黄铁矿氧化固铀的影响。结果表明:无CO2分压下中性Tris缓冲体系中黄铁矿氧化对U(VI)的吸附率高达90%,有CO2分压下碳酸铀酰体系中铀的固定率明显降低,约有32%的铀被吸附。在方解石和黄铁矿共存体系中,单独通O2条件下铀的吸附率为27%,CO2和O2共通时黄铁矿氧化对铀的吸附率仅为2%,结合数值模拟结果表明O2+黄铁矿+方解石体系和CO2+O2+黄铁矿+方解石体系中Ca2(UO2)(CO3)3质量比分别为80%和95%。X射线衍射(X-ray diffraction,XRD)、X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和傅里叶红外光谱(Fourier transform infrared,FT-IR)结果表明黄铁矿表面发生微氧化形成针铁矿和纤铁矿会增加U(VI)的吸附,方解石溶解促进Ca-UO2-CO3络合物的形成影响了黄铁矿及其氧化产物对U(VI)的固定,提高了U(VI)的迁移能力。 |
| 英文摘要: |
| 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 dissolution. 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 dissolution on uranium fixation by pyrite oxidation under CO2 and O2 conditions was comparatively 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 carbonate 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 pyrite oxidation was only 2% when CO2 and O2 are combined. The numerical simulation results 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 photoelectron 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). |
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