关键词: 导热系数, 白垩系岩石, 扫描电镜（SEM）, 晶格振动理论

Abstract: Thermal conductivity is great significance for us to make an alysis heat conduction law study on heat conduction characteristics of rock, it is also the freezing method construction through the important thermal physical parameters of surrounding rock.Closely related to the thermal conductivity coefficient and inner rock mineral composition, micro structure, but the research on this field is less, effect of the concrete microstructure on thermal conductivity isn’t system.In this paper, based on the Xinzhuang colliery of Cretaceous formation water rich sandstone as the research object, the medium grained sandstone and the coarse-grained sandstone as the field acquisition representative of sandstone for indoor test , first of all, setted room temperature water saturation coefficient of heat conductivity test for two kinds of sandstone, the coefficient of thermal conductivity of obtaining the corresponding value range;.Then, X-ray diffraction, scanning electron microscopy (SEM) were launched microscopic test, obtain two kinds of sandstone respective inherent mineral components and structure, and thermal characteristics of the inner mineral composition has carried on the system analysis;Finally, combining with the lattice vibration theory, analyzes the relationship between the thermal conductivity and microstructure of sandstone . the results of the study indicate that: thermal conductivity rate of water saturated Cretaceous sandstone depends on the size of thermal conductivity rate of rock skeleton and gap liquid .Since the Cretaceous sandstone with low porosity, rock skeleton of Cretaceous sandstone thermal conductivity rate depends on the size of mineral composition of rock.

Key words: thermal conductivity, Cretaceous rocks, scanning electron microscope (SEM), lattice vibration