黏土型锂矿石的常温原位柱浸工艺探究OA

The clay-type lithium ores,a significant lithium resource in China,contain lithium and other elements such as aluminum and silicon.Their molecular formulas are expressed as LiAl[SinO2n+2]and Li[AlSinO2n+2]in this study.The latter formula represents the ion-absorbed lithium ores,from which lithium ions can be readily extracted in leaching experiments.This study explores an environment-friendly,economical,normal-temperature in situ leaching technique for clay-type lithium ores,which requires that the chemical proper-ties of lithium ores remain unchanged before leaching experiments.The contents of various elements,loss on ignition,and porosity(mas-sive ores)of clay-type lithium ores were analyzed through the column leaching experiments.Three leaching reagents were used:10%sul-furic acid solution,10%ammonium sulfate solution,and a mixture of 5%sulfuric acid solution and 5%ammonium sulfate solution.The total leaching process lasted for 190 d.The concentrations of lithium and aluminum were determined at regular intervals.The experimen-tal results show that the porosities of the clay-type lithium ores ranged from 0.38%to 6.20%.The first and third reagents demonstrated higher leaching efficiency,achieving a Li2O leaching rate of up to 0.56%without refilling fresh reagents,whereas the leaching efficiency of the second reagent was not satisfactory.Notably,in the case of a reduced ore size,the third mixed leaching solution yielded the same leaching efficiency as the first high-concentration sulfuric acid solution.Overall,this study provides a practical in situ leaching technique for clay-type lithium ores in mines.