Explanation

sedimentary rock with caldte as the main mineral. The mineral composition is mainly caldte, but contains some terrigenous detritus and clay mineral, such as various sands, silty sands, flint, dolomite, etc. The relatively pure limestone is generally gray and light gray, grayish white and yellowish white with argillaceous or dolomite, and grayish black and dark gray with more organic matter. hardness 3, add dilute hydrochloric acid to strongly foam. According to composition, it can be divided into limestone, argillaceous limestone and inner dolomite limestone; According to its structure, it can be divided into fine-grained bright crystal limestone (such as bamboo leaf shaped limestone, oolitic limestone, bioclastic limestone, etc.), shoulder microcrystalline limestone, mud crystal limestone, reef limestone, algal limestone, etc. It is the main raw material for producing Portland cement: it can be used as flux for smelting; It is also used in the production of soda, calcium carbide, dye or dyestuffc, bleach, paper making and fertilizer; Can be used as a clarifying agent in the food industry; It can be used as the ingredient of porcelain glaze in the ceramic industry, and as an adsorbent in environmental protection. It can be used to improve soil and livestock materials in agriculture and animal husbandry: it can be used to burn lime or directly used as building stone, railway crosstie pad stone. limestone with uniform crystal and special texture can be used as high-grade decorative stone. Pure and transparent iceland spar can sometimes be formed in the large cracks or cavities of limestone. It is a precious optical materials, and some crystal families of crystal caldte are also advanced handicrafts. Some microcrystalline siliceous limestone is a precious raw material for inkstone because of its compactness and fineness, small pores and even distribution of microcrystalline quartze particles.

Classification