EFFECT OF A COMPLEX SURFACTANT ON IN SITU LEACHING OF LOW PERMEABLE SANDSTONE URANIUM DEPOSITS

The effect of a complex surfactant on in situ leaching of low permeable sandstone uranium deposits is discussed, based on an Agitation leaching and a column leaching experiments. The results of the Agitation leaching experiment show that adding different concentrations surfactant into leaching solutions increases significantly the leaching rate of uranium. For a surfactant concentration of 10 mg/l, the leaching rate of uranium reaches maximum 92.6%. The results of the column leaching experiment show that adding 10mg/L surfactant into leaching solutions increases the permeability coefficient of ore-bearing layer 28.8% and the leaching rate of uranium 58.0%, resulting in 85.79%. The results of kinetic analysis show that extraction of uranium is controlled by diffusion with apparent rate constant of 0.0023/d without adding surfactant and by surface chemical reaction with apparent rate constant of 0.0077/d with adding surfactant. Thus, for low permeable sandstone uranium deposit, the in situ leaching mining is of great potential if adding the complex surfactant into leaching solutions.