In this study, the physical characteristics of alumino-silicate geopolymer and the role of mine tailings in alumino-silicate geopolymer were investigated using mine tailings, coal fly ash, granulated blast furnace slag and alkali activator solution. The reaction products of alumino-silicate geopolymer using mine tailings are amorphous aluminosilicate gel and calcite, and are increased with decreasing the addition of mine tailings. The compressive strength of MRG-2 specimen is the highest as 142.2MPa. The compressive strength of specimen adding mine tailings is decreased, as curing days are increased. When curing days are same, the compressive strength is decreased, as mine tailings is added more. The compressive strength of alumino-silicate geopolymer manufactured by adding mine tailings is higher than that of portland cement mortar, when cured for 28 days. The leaching resistance of heavy metal ion in alumino-silicate geopolymer is lower than the toxic threshold of each ion. It is confirmed that heavy metals are stabilized and fixed in alumino-silicate geopolymer.

Keywords: Alumino-silicate geopolymer; Mine tailing; Fly ash; Slag; Compressive strength