Multivariate analysis of trace elements leaching from coal and host rock

Abstract Trace elements in coal mine water have pollution potential to environmental water bodies. By process of water-rock interaction in coal seam and coal host rock, trace elements may immigrate from solid matrix to water, including oxidation, dissolution, ion-exchange, adsorption-desorption, etc. Water parameters and occurrence of trace elements in the solid matrix are keys to leaching behavior. In site observation and leaching experiments were designed and implemented so as to model these processes, analyze leaching behavior and mechanisms. The data composes a matrix by two dimensions, samples and trace elements, which were used to analyze trace element occurrence in coal, host rock and leaching behavior in the coal/rock leaching water, by method of multivariate analysis. Analytical results showed major occurrence of trace elements in the coal and host rock and key controlling mechanism of trace elements during water-rock interaction: in coal host rock seam, Se/Cd/Hg/As occurred in sulfide minerals, Be and V occurred in carbonate minerals, Cr and Pb occurred in clay minerals, respectively. Se, As and Hg immigrated through dissolution of sulfide minerals, Cr immigrated through transformation of clay minerals. In coal seam, Se/Cr/Pb occurred in clay minerals, As and Hg occurred in sulfide minerals. Se, Pb and Cr immigrated through transformation of clay minerals, As and Hg immigrated through dissolution of sulfide minerals, respectively.