Coal System Of Carboniferous-Permian Coal Measures In Hancheng Mining Area

As the main energy of our country,coal plays an irreplaceable role in the development of the national economy.Hancheng mining area is one of the main coal production bases in Shaanxi Province,and its safe and efficient mining is restricted by geological factors.Taking Hancheng mining area as the research object and the theory of coal system as a guide,the coal system of Carboniferous-Permian coal measures is analyzed in this paper.It is expected that it will be helpful for further understanding of the occurrence law of coal resources and improving the efficiency of coal mining.Coal system is one or several coal seams and groups that are the same or similar in the material source,coal gathering environment and coal formation effect.It is a complex system composed of many elements.Based on the analysis of the water medium conditions of the paleo-peat swamp,this paper systematically studies the basic characteristics of the components of the coal system from the accumulation of the paleo-peat material to the whole process of coal formation and transformation.The Carboniferous-Perrmian coal measures in Hancheng mining area is divided into 4 coal systems(A-D)in vertical direction,taking ash and sulfur content of coal,the sequence stratigraphic framework of coal measures,lithofacies paleogeography,development law of coal seam(group),structural differences of coal bearing blocks,the degree of metamorphism of coal as the main symbols.And according to the spatial difference of the various symbols,the unit of each coal system is divided horizontally.The coal system A corresponds to sequence CS ?,mainly composed of lagoons and tidal flat deposits,and mainly developed high sequence formation and transgressive sequence formation.Among them,the first stratification of K2 limestone is the third largest flooding surface.11#coal is a stable and minable coal seam in the whole area with low volatilization,medium ash,high sulfur lean coal,and there is a large range of anthracite in the northwest of mining area.The coal system B corresponds to sequence CS ?,mainly composed of tidal flat,barrier island,lagoon,carbonate platform and other sedimentary environments,and mainly developed transgressive sequence group and high rank sequence group.Among them,5#coal is only available in the southern region with low volatilization,medium ash,low-medium sulfur lean coal.The coa system C corresponds to the fourth order sequence S6 in CS?,which is mainly composed of distributary channel and interdistributary bay sedimentary environment,mainly developed low and lacustrine transgressive sequence formation.3#coal is a relatively stable coal seam with low volatilization,medium-rich ash,low-medium sulfur lean coal,and there is a large amount of anthracite in the west of Wang Feng mine field.The coal system D corresponds to the fourth order sequence S7-S8 in sequence CSIII,which is dominated by the distributary channel and interdistributary bay sedimentary environment,and develops high sequence formation.2#coal is sporadic and minable unstable coal seam with low volatility,medium-rich ash,low sulfur lean coal.In the vertical direction,the coal system A has relatively good coal forming conditions.On the plane,the A4 unit of the coal system A,the B2 unit of the coal system B,and the C2 unit of the coal system C have relatively good coal-forming property.