CCSEM investigation on the mineral properties of six Chinese typical steam coals

Computer-controlled scanning electron microscopy (CCSEM) was used to investigate the properties of min- erals in six Chinese typical steam coals. The mineral species compositions,spatial distributions,particle sizes and ele- ment distributions in minerals were obtained. The results show that for the used coals,oxide mineral contents are high in low rank coals,clay minerals are dominant in high rank coals,carbonate and sulfide mineral contents are high in specific coals,and sulfate and other minerals contents are low in each coal;the contents of various types minerals are arranged from high to low as follows:clay minerals,oxide minerals,carbonate minerals,sulfide minerals,sulfate miner- als and other minerals;the excluded mineral accounts for 76. 3% of total mineral in mass;the average particle size of excluded minerals is significantly larger than that of included minerals;the average mineral particle sizes are arranged from large to small as follows:oxide minerals,carbonate minerals,clay minerals,sulfide minerals,sulfate minerals and other minerals;Si and Al mainly distribute in clay minerals,Ca,Fe and S distribute dispersedly in many types of min- erals.