Calcium carbonate is an important building material. White and pure calcium carbonate rock is called white marble, which can be directly used as decorative stone pillars or handicrafts; Calcium carbonate with beautiful patterns because of impurities is called marble, which is used to cover the outer and inner walls of buildings or lay the ground; Dense calcium carbonate rock (limestone) can also be directly used for building, but the main use of limestone is to produce cement. The white stone containing more than 90% CaCO3 is crushed, classified and separated by raymond mill or other high-pressure mills to obtain the finished product.