gas evolution
3.New technique feature: sodium silicate add volume<3%, high strength (tensile strength 0.5～1.4 MPa), good mold sand and core sand synthetical property (good hard pencil property in the winter, curing time 10～80 min), low gas evolution, good collapsibility (relained strength 400 ℃<0.5 MPa,≥800 ℃ 1/10 as CO 2 sodium silicate bonded sand).
6.Based on analyzing such characteristics forming gas reservoirs as the features and distribution of gas source rocks, distribution of gas reservoirs and gas source areas, gas reservoir distribution and faults, main periods for forming gas reservoirs, and gas accumulation types, as well as the structural evolution characteristics and recent exploration achievements of the basin, the gas exploration areas of the basin are basically identified, including the Carboniferous of eastern Luliang uplift-Wucaiwan sag-Baijiahai uplift, the Jurassic of Muosuowan uplift-Mobei uplift-western Luliang uplift in the central depression, the Upper Cretaceous and Paleogene of the frontland thrust belt, and the deep Carboniferous and Permian of Mosuowan anticline in the central depression of the basin.
8.In order to determine gas content accurately in Seam 3 of Chengzhuang Coal Mine, qualitative and quantitative analysis in terms of seam thickness, metamorphic grade, burial depth, roof and floor lithologic characters, hydrological conditions and geologic structure proves that the thickness of the overlying bedrock was considered to the main control action factors to gas content, based on coal geologic data and actual gas emission data integrating with region tectonic evolution characters.
