摘要
Abstract
The"CO2+O2"leaching process is an artificially intensified water-rock interaction process that leads to the dissolution of non-uranium minerals,which enter the leaching solution system and cause changes in the dissolution and precipitation state of the minerals in the leachate.Geochemical simulation methods were used to simulate ion species in the leachate and the mineral leaching equilibri-um studying the dissolution,migration,and precipitation of minerals during the in-situ leaching min-ing process.For the first time,the conditions and influencing factors for the precipitation of manga-nese minerals were studied,targeting the characteristics of strong groundwater reducibility and high carbonate content in the target deposit.The results show that under neutral leaching conditions,ura-nium in the leachate mainly exists in the form of UO2(CO3)34-followed by UO2(CO3)22-,and the pro-portions of the two are affected by pH.The saturation indices of carbonate minerals in the neutral leaching leachate of the study area are all greater than zero,indicating a supersaturated state,and pH is the main factor controlling the precipitation of carbonates,with the critical pH for calcium carbon-ate precipitation being 6.7 and for calcium magnesium carbonate precipitation being 6.5.The satura-tion indices of sulfate minerals are all less than zero,and no precipitation of calcium sulfate will occur in the formation,and the precipitation of calcium sulfate is mainly controlled by the content of calcium ions and sulfate ions.Under neutral leaching conditions,iron mineral precipitation is likely to occur and is greatly affected by pH conditions;at the same time,manganese-containing minerals will precip-itate in the leachate,and the redox conditions are the main factors affecting their dissolution and pre-cipitation;some silicon-containing minerals in the leachate are in a supersaturated state,and their dis-solution and precipitation are greatly affected by pH The research results are of great significance for the prevention of precipitation in in-situ leaching mining.关键词
"CO2+O2"浸出/地球化学模拟/PHREEQC/浸出液/离子存在形式/矿物溶解沉淀Key words
"CO2+O2"leaching/geochemical simulation/PHREEQC/leachate/ion species/mineral dissolution and precipitation分类
能源科技
