Mineralogy and Geochemistry of the Lower Cretaceous Coals in the Junde Mine, Hegang Coalfield, Northeastern China

Hegang coalfield is one of the areas with abundant coal resources in Heilongjiang Province. Characteristics of minerals and geochemistry of No. 26 coal (lower Cretaceous coals) from Junde mine, Hegang coalfield, Heilongjiang province, China, were reported. The results showed that No. 26 coal of Junde mine is slightly enriched in Cs, Pb, and Zr compared with world coals. The minerals in No. 26 coal of Junde mine primarily include clay minerals and quartz, followed by calcite, siderite, pyrite, monazite, and zircon. The diagrams of Al2O3-TiO2, Zr/Sc-Th/Sc, Al2O3/TiO2-Sr/Y, and Al2O3/TiO2-La/Yb indicate that the enriched elements in No. 26 coal were mainly sourced from the Late Paleozoic meta-igneous rocks in Jiamusi block. The volcanic ash contribution to No. 26 coal seems very low. Sulfate sulfur indicating oxidation/evaporation gradually decreases during No. 26 coal formation.