Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

The waste limes, residual cakes mainly from the production processes of soda ashes, are abandoned in the open field to be sources of environmental contamination. To assess their potential applicability for the prevention of the environmental disruption caused by the abandoned mines, the waste limes were characterized and treated with heat to be tested for neutralization of acidic water and stability. The waste limes were of 0.1㎛ to 1.0㎜ in size, of 11.24 for pH, and composed mainly of calcite, quartz, plagioclase and others. The globular specimens were prepared by mixing waste limes and stone dust sludges from quarries with various ratios and heated for one hour at 600℃, 800℃, and 1,000℃, respectively. As the temperature of heat treatment increased and the mixture ratio of stone dust sludge decreased, the specific gravity of specimen generally decreased but the water absorption capacity increased. The specimen sintered at 600℃ showed a relatively low loss of weight in the result of the abrasion test by reciprocating vibration in water. Regardless of the mixture ratio of waste limes and stone dust sludges, the heat treated specimens were effective for neutralization of acidic drainage when the specimens of 0.5 to 1.0g were added to every liter of acidic drainage in the assumption that the reaction time was longer than 5 days. The smaller the size of heat treated specimen made of only waste limes, the higher its compressive strength. It is suggested, therefore, that the waste limes with heat treatment can be utilized effectively for the prevention of the environmental disruption such as acid mine drainage and subsidence in some abandoned mines.