Inorganic Precipitation of Calcite in Mine Tailings Using Trona

Mine tailings pose environmental risks such as dust emission and acid mine drainage (AMD) and also present geotechnical risks, i.e. tailings dam failures. In-situ cementation of tailings has the potential to reduce the risks associated with such failures as well as the related environmental problems. In this paper, a new inorganic method of inducing tailings cementation is introduced using a naturally occurring mineral called trona (Na2CO3 center dot NaHCO3 center dot 2H(2)O). Three methods of introducing dissolved trona, i.e. injection, slurry mixing, and infiltration, were tested and the results were compared. All methods proved successful on a laboratory scale but with different amounts of precipitated calcite at different sample depths. The precipitation profile distinctions could have applications in solving common problems associated with tailings including dust emission and liquefaction. Additionally, even distribution of precipitated calcite in the slurry mixing method shows potential for AMD prevention.