High purity carbonate rock

High purity carbonate rock is limestone containing more than 95 % of (CaCOg- MgCOa). 

Metallurgical-grade limestone is a high purity carbonate rock used in metallurgical process to flux solid impurities. 

Silicon is the second most abundant element in the Earth s crust. It occurs widely in rocks as silicates, compounds containing the silicate ion, Si032, and as the silica, Si02, of sand (Fig. 14.33). Pure silicon is obtained from quartzite, a granular form of quartz (another solid phase of SiOz), bv reduction with high-purity carbon in an electric arc furnace ... 

In the manufacture of glass wool, the raw materials are those usually used in the glass industry i.e. sand, lime, dolomite, feldspar, kaolin, alumina-containing volcanic rocks, sodium carbonate, sodium sulfate, potassium carbonate and boron minerals. The purity requirements particularly as regards iron content are not particularly high. 

Calcium carbonate exists in three crystalline modifications (calcite, aragonite, vaterite), but only calcite has practical importance. It can be found in large quantities all over the world, but fillers mined at different locations differ considerably in purity, size of the crystals and origin, which all influence their use as fillers. In nature, it can be found in three different forms limestone, chalk and marble. Limestone is a consolidated sedimentary rock formed by the deposition of shells and skeletons of marine organisms, chalk is soft-textured limestone laid down in the cretaceous period and consists of nanofossils marble is metamorphic limestone formed under high pressures and temperatures. CaCOj occupies second place in usage behind talc in PP. 

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