摘要
根据地浸液pH、ρ(HCO-3)及UO2+2与CO2-3的3级配合常数和HCO-3的二级电离常数,计算了地浸液中3级碳酸铀酰配合形态的生成摩尔分数与地浸液组成关系;明确了pH、ρ(HCO-3)两者对UO2CO3沉淀量和UO2(CO3)4-3/UO2(CO3)2-2物质的量的比的影响规律,指出了地浸液在pH为7.0左右、ρ(HCO-3)约为1g/L时,UO2CO3沉淀率仅为六价铀物质的量的1%,可确保好的浸出率。当矿床的地下水本身pH及ρ(HCO-3)较高、不易导致产生化学沉淀堵塞地浸液流通时,为了强化铀浸出,地浸液的上述2个主要组分浓度可适当高些。此外,讨论了地浸过程中可能的化学沉淀、堵塞及其影响因素;指出CO2+O2地浸采铀仅适宜于碳酸盐含量较高的砂岩铀矿床,否则需增加HCO-3,以强化铀的浸出。
Abstract： According to the main composition of leached liquor pH, HC03 concentration as well as three grade stability constants of U02/2＋ with C032- and two grade ionization constant of HC03, the re- lationship between the yielded mole fraction percentage of three grade uranyl carbonate complex and composition of leached liquor was calculated. The influence rule of both pH and HC03- concentration to UO2 CO3 precipitation quantity and the mole ratio of UO2 （CO3） 4/3- / （CO3） 4/3-/UO2 （CO3） 2/2- was de- termined. It is pointed out that when leached liquor pH is about 7, HCO3- concentration is about 1 g/L, and precipitation percentage rate of UO2CO3 is about 1% of sexivalent uranium, good leaching rate can be guaranteed . When pH and HCO3- concentration is higher in the natural aquifer, and pro- duction of chemical precipitation is not easily formed to block leaching liquor circulation, the two com- ponents can be properly higher in order to intensify uranium leaching. The chemical precipitation, blocking and other influence factors in in-situ leaching process are also discussed. CO2 ＋02 in situ leaching uranium is only suitable to high content of carbonate kind of sand stone uranium deposit, oth- erwise, HCO3- has to be added in order to intensify uranium leaching.
出处
《铀矿冶》
CAS
2014年第4期197-202,222,共7页
Uranium Mining and Metallurgy
关键词
CO2+O2地浸采铀
碳酸铀酰配合物
化学沉淀堵塞
CO2 ＋02 in situ leaching uranium
uranyl carbonate complex
chemical precipitation bloc-king
