龙门山地区天井山组灰岩特征及综合利用

Limestone characteristics and comprehensive utilization of Tianjingshan Formation in Longmenshan area

川西北龙门山地区三叠系天井山组灰岩分布广泛,为传统优质水泥和饰面用材料,其利用方式较为单一,资源利用效率有待提高。通过研究天井山组灰岩的地质特征及物理力学性质,探讨了各类用途的可行性。区内灰岩w(CaO)为51.78%~55.20%,密度为2.51~2.73g/cm^3,硬度为3°,天然吸水率为0.2%~0.8%,抗压强度为27.51 MPa^82.4 MPa,抗折强度为14.5 MPa^30.68 MPa,坚固性在2%~3%之间,压碎指标值在8.6%~9.6%之间,耐磨度为28/cm^2~64/cm^2,天然放射性比活度内照射指数(IRa)为0.03~0.34,外照射指数(Ir)为0.02~0.19,可广泛运用于石材、溶剂、水泥等各个领域。总结了天井山组灰岩的利用模式:饰面石材→溶剂、制碱、电石灰→重钙粉→水泥→米黄色马赛克、人造大理石板材。以期为灰岩矿产的综合利用和绿色矿山建设提供参考和依据。

Triassic Tianjingshan Formation limestone is widely distributed in the Longmenshan area,northwest of Sichuan.It is the traditional high-quality cement and decorative material.The utilization model is relatively single,and it is necessary to improve the utilization efficiency of resources.In this paper,the feasibility of various uses is discussed by studying the geological characteristics and physical and mechanical properties of Tianjingshan Formation limestone.The CaO content of limestone is 51.78%-55.20%,density is 2.51-2.73 g/cm^3,hardness degree is 3°,natural water absorption is 0.2%-0.8%,compressive strength is 27.51 MPa-82.4 MPa,flexural strength is 14.5 MPa-30.68 MPa,firmness is between 2%and 3%,crushing index is 8.6%-9.6%,wear resistance is 28/cm^2-64/cm^2,natural radioactivity internal irradiation index(IRa)is 0.03-0.34,and external irradiation index(Ir)is 0.02-0.19.It can be widely used in stone,solvents,cement and other fields.The utilization modes of Tianjingshan Formation limestone are summarized as follows.Facing stone→Solvent,Alkali,Calcium Lime→Heavy calcium powder→Cement→Beige mosaic,artificial marble board.It is hoped that the paper could provide some reference and basis for the comprehensive utilization of limestone mineral resources and construction of green mines.