It is of two types
- Potassium Feldspar
- Sodium Feldspar
It is generally marketed after grinding to specified mesh a/c to consumer’s need. Some firms sell feldspar after pulverizing especially for glass industry and some firms utilizing feldspar as a binding agent in manufacturing of abrasives. Rajasthan was leading producer with a little over half of the total production of feldspar while about one fifth of the production is exported mainly to Singapore, China Republic, Malaysia and Japan.
- Chiefly utilized in manufacturing of glass pottery. It provides alumina and alkalis. Potash feldspar (orthoclase) tends the melt to clear glass while as soda feldspar (albite) tens the melt to translucent glass. It is used for making high class colourless glass.
- It is used in ceramic industry. It is used as glazes in chinaware. In ceramic bodies or in development of ceramic bodies both potash and soda feldspar are used.
- It is also used in welding electrodes. Feldspar act as flux and protects the molten metal from aerial oxidation.
- Finely ground feldspar quite suitable as a filter in latex and paint both. Feldspar also utilized in manufacturing of vitrified enamels.
- It is useful in production of special electrical porcelain, wind plates and opalescent glass. Small quantity of it also used for enameling artificial teeth.
Chemical Composition of Feldspar