STUDY ON THE ENCAPSULATION TECHNOLOGY TO CONTROL THE ACID MING DRAINAGE
YIM, Gil-Jae1, JI, Sang-woo2, CHEONG, Young-Wook1, SEO, Eui-Young3 and CHAE, Byung-Gon2, (1)Korea Institute of Geoscience & Mineral Resources, Gwahang-no 92, Yuseong-gu, Daejeon, 305-350, Korea, Republic of (South), (2)Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources, 92 Gwahang-no, Yuseong-gu, Daejeon, 305350, Korea, Republic of (South), (3)Devision of Energy & Resources Engineering, Kangwon National University, Chuncheon, 200-701, Korea, Republic of (South), gjyim@kigam.re.kr
Acid ming drainage generated in mining areas are created by reactions between rocks containing sulfide minerals and oxygen in the atmosphere or surface water. If metal mine or coal mine is abandoned, and pump drainage in the mine is stopped, mine cavity, shaft and conveyance road will be filled with ground water. Because these kinds of underground spaces will be the path of mine water, stratum of vodase zone is contacted with mine water while water level is increased as time passes, geochemical properties of mine water will be changed. This change generates the acid ming drainge or leachate from goaf or rock waste resulting contaminations. It has been reported that water contamination in the mine water is expected when total sulfur contents in the stratum is more than 1% (Younger et al., 2002).
The purpose of this study is to develop the technology which prevents the acid ming drainage and the contaminations due to surrounding rock wastes for mine cavities generated by mining developments. To achieve the goals, encapsulation studies on the sulfide minerals existed in the mine cavities will be executed as one of the source control water contamination preventing technology to suppress the acid ming drainage development.
For the source control, from the results of rice meter tests for applying calcium silicate as encapsulation liquid, specimens from 4 other zones maintain the encapsulation effects after 3 months (Most specimen of calcium silicate 1M and 0.5M increase from pH3 to pH6-7.). Increasing effects of pH have been confirmed through encapsulation, and encapsulation effects based on proper particle size were increased.
Liquid using calcium silicate has been developed as the encapsulation liquid to suppress the acid ming drainage development and process which applies this liquid to mine cavities and mine waste dumps has been established. Also, from encapsulations, pH increasing effects and decreasing of Fe and sulphate were confirmed. From these results, it is judged that 1M (mole) of liquid is the liquid which can be applied to the mine cavity and mine waste dump.
