Characteristics and geological genesis of pyrites in coal of Huainan

Using optical microscope and scanning electron microscopy （SEM）, revealed the content of pyrite and the microscopic or sub-microscopic occurrence features of pyrite in coal of Huainan. The samples of this study are from four different mines in Huainan coal field. The results show that, in general, the coal of Huainan is low sulfur coal, but the con- tent of pyrite in Guqiao mine is relatively higher. The occurrence types of pyrite in coal mainly include： strawberry ball pyrites, massive pyrites, tuberculoid pyrite and pyrite filling in cracks or joints. After analysis based on three indicating facies parameters IAA, IS and/R, the reason for the higher level of pyrite component is that the deoxidization of swamp wa- ter is stronger, salinity is greater and the hydrodynamic is bad. The strawberry ball pyrites found in Guqiao mostly formed in the syngenesis stage. The spherical raspberry pyrites symbiotic with clay minerals was formed due to the reaction of H2S with Fe in the grid of silicate crystal.

Using optical microscope and scanning electron microscopy (SEM), revealedthe content of pyrite and the microscopic or sub-microscopic occurrence features of pyritein coal of Huainan.The samples of this study are from four different mines in Huainan coalfield.The results show that, in general, the coal of Huainan is low sulfur coal, but the contentof pyrite in Guqiao mine is relatively higher.The occurrence types of pyrite in coalmainly include: strawberry ball pyrites, massive pyrites, tuberculoid pyrite and pyrite fillingin cracks or joints.After analysis based on three indicating facies parameters /_(AA),/_S and /_R,the reason for the higher level of pyrite component is that the deoxidization of swamp wateris stronger, salinity is greater and the hydrodynamic is bad.The strawberry ball pyritesfound in Guqiao mostly formed in the syngenesis stage.The spherical raspberry pyritessymbiotic with clay minerals was formed due to the reaction of H_2S with Fe in the grid ofsilicate crystal.