• Economic and Environmental Geology
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• v.36 no.2
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• pp.103-109
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• 2003

The mineralogy of material left after evaporation of acid mine drainage water is generally dependent on the chemical composition of the source water. The residues formed by the evaporation of acid mine water in the Dong-hae coal mine area consists mainly of gypsum (CaSO$_4${\circ}$2$H_2O$) with mine. amounts of alunogen (Al$_2$(SO$_4$)$_3$${\circ}$17$H_2O$) and hexahydrite (MgSO$_4$${\circ}$<.TEX>6$H_2O$). Gypsum was identified from both of the bottom precipitates and the evaporation residues of acid mine water. Alunogen, an aluminum sulfate hydrate, was also formed by evaporation and occurred as needle-like crystals. Aluminum is derived from chemical dissolution of alumine-silicate mineral such as pyre-phyllite, illite and chlorite in wasted rocks. Hexahydrite in evaporation residues occured as needle-like, fibrous, and acicular crystals and was associated with gypsum and alunogen.