Potash feldspar, also known as orthoclase, belongs to monoclinic system. It is usually flesh red, white or gray. Density 2.54-2.57g/cm, specific gravity 2.56-2.59g/cm3, hardness 6. It has the characteristics of low melting point (1150 ± 20 ℃), long melting interval and high melting viscosity. It is widely used in industrial sectors such as ceramic blank, ceramic glaze, glass, electric porcelain and grinding materials, and in the production of potash fertilizer.