Kinetics of uranium extraction from coffinite——A comparison with other common uranium minerals  

水硅铀矿及其他常见铀矿的铀浸出动力学比较（英文）

作　　者：H.S.REYNOLDS R.RAM M.I.POWNCEBY Y.YANG M.CHEN J.TARDIO L.JONES S.K.BHARGAVA H.S.REYNOLDS;R.RAM;M.I.POWNCEBY;Y.YANG;M.CHEN;J.TARDIO;L.JONES;S.K.BHARGAVA(Centre for Advanced Materials and Industrial Chemistry(CAMIC),School of Applied Sciences,RMIT University,GPO Box 2476,Melbourne VIC 3001,Australia;School of Earth Atmosphere and Environment,Monash University,9 Rainforest Walk,Clayton,Victoria 3800,Australia;CSIRO Mineral Resources,Private Bag 10 Clayton South,Victoria 3169,Australia)

机构地区：[1]Centre for Advanced Materials and Industrial Chemistry(CAMIC),School of Applied Sciences,RMIT University,GPO Box 2476,Melbourne VIC 3001,Australia [2]School of Earth Atmosphere and Environment,Monash University,9 Rainforest Walk,Clayton,Victoria 3800,Australia [3]CSIRO Mineral Resources,Private Bag 10 Clayton South,Victoria 3169,Australia

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第10期2135-2142,共8页中国有色金属学报（英文版）

摘　　要：A synthetic coffinite was hydrothermally prepared and characterized before conducting a series of acid sulfate leach tests under conditions of relevance to uranium extraction.The results were then compared with similar studies on synthetic versions of the related U4+minerals uraninite(UO2)and brannerite(UTi2O6)to identify and differentiate the rate and U extraction among these important uranium minerals.Tests examining the influence of residence time on uranium dissolution from synthetic coffinite,uraninite and brannerite showed that under similar experimental conditions,complete dissolution of uranium from coffinite was obtained between 36 and 48 h.The activation energy for this reaction was calculated to be 38.4 kJ/mol.This represented a significantly slower rate of dissolution than that indicated for uraninite which dissolved in 3 h(Ea=15.2 kJ/mol).The synthetic brannerite was leached at a much slower rate than the coffinite and reached a maximum dissolution of^18%U in 144 h(Ea=42-84 kJ/mol).The clear differentiation in rates and U extraction among the three minerals is consistent with previous literatures which suggest that in terms of leachability,uraninite>coffinite>brannerite.It is expected that the presence of impurities in natural coffinites would further inhibit leachability.水热合成并表征水硅铀矿,在此基础上对水硅铀矿在硫酸体系中的浸出过程进行研究,并将结果与其他相关的合成U^(4+)矿物如氧化铀(UO_2)和钛铀矿(UTi_2O_6)在类似条件下的浸出速率和浸出率进行比较。浸出时间对铀溶出影响的研究表明,水硅铀矿在36~48 h被完全浸出,该反应的活化能为38.4 kJ/mol。与水硅铀矿相比,氧化铀矿的溶出速率明显较快,可以在3 h内达到完全溶出(E_a=42~84 kJ/mol)。比较而言,合成钛铀矿的浸出速率较水硅铀矿的明显更低,其144 h铀的最大浸出率只有18%。上述3种矿物溶出速率和提取率的显著区别与文献报道相符合,即矿物的可溶出性为氧化铀>水硅铀矿>钛铀矿。在天然水硅铀矿中,由于杂质的存在,其可溶出性可能会被进一步抑制。

关 键 词：COFFINITE URANINITE BRANNERITE acid leaching extraction kinetics 

分 类 号：TL212.12[核科学技术—核燃料循环与材料]