Ms Kothari Minerals

Beawar, Ajmer, Rajasthan

China clay results from alteration of Feldspars. Granite, Gneiss & pegmatite are the main source of feldspars. The process of alteration is known as Kaolinisation.The quality of china clay depends much upon the colour, natural fineness. China clay is worked by the open-cut method. China clay found in two modes, residual & sedimentary. Sedimentary deposits having natural purity but residual deposits require to be washed to remove impurities. The most common method of washing is the process of Levigation & Sedimentation. Under this process china clay is mixed with sufficient quantity of water and allowed to flow through different channels and tanks. The heavier particle settle down in Levigating tank and china clay suspended in water flows through different tanksand goes on setting. And after settling the pasty clay is pumped by slurry pumps and fed to filter press and clay obtained in form of cakes, further followed by drying the cakes in sun light.

Feldspar comprises a group of minerals containing potassium, sodium, calcium & aluminum. They are the most common rock-forming minerals. The common feldspar is potassium feldspar, namely, orthoclase (K [AlSi3O8]), sodium feldspar, is albite (Na[AlSi3O8]) and calcium feldspar is anorthite(Ca[AlSi3O8]).Potash and soda feldspar occur as essential constituents of granite, syenite and gneisses. Workable deposits are found in pegmatite veins consisting mainly of feldspar, quartz-feldspar veins and also occur with mica pegmatite.

Feldspar comprises a group of minerals containing potassium, sodium, calcium & aluminum. They are the most common rock-forming minerals. The common feldspar is potassium feldspar, namely, orthoclase (K [AlSi3O8]), sodium feldspar, is albite (Na[AlSi3O8]) and calcium feldspar is anorthite(Ca[AlSi3O8]). Potash and soda feldspar occur as essential constituents of granite, syenite and gneisses. Workable deposits are found in pegmatite veins consisting mainly of feldspar, quartz-feldspar veins and also occur with mica pegmatite.

Feldspar comprises a group of minerals containing potassium, sodium, calcium & aluminum. They are the most common rock-forming minerals. The common feldspar is potassium feldspar, namely, orthoclase (K [AlSi3O8]), sodium feldspar, is albite (Na[AlSi3O8]) and calcium feldspar is anorthite(Ca[AlSi3O8]). Potash and soda feldspar occur as essential constituents of granite, syenite and gneisses. Workable deposits are found in pegmatite veins consisting mainly of feldspar, quartz-feldspar veins and also occur with mica pegmatite. »Industrial Applications   Feldspar is generally used for: (1) In making the body composition of several types of porcelain, tiles, earthenware & in preparation of glazes & enamel.(2)as an important ingredient in the glass sand batch(3) as a bonding agent in the manufacture of bonded abrasives (4)in acid proof refractories (5)as a flux in welding electrode industries.     »Resources in India:   Rajasthan produces the largest quantity of Feldspar and accounts for over 70% of the country total production. Feldspar mainly mined from Ajmer, Alwar, Jaipur, Pali, Sikar, Tonk, Bhilwara, Amet, Rajsamand. At Beawar (about 50 k.m. from Ajmer) there are more than 350 processing plants. Other States are Tamilnadu, Andhra pradesh, Bihar & Jharkhand.

China Clay also called Kaolin falls under Kaolinite group. The essential property of this group is that they do not swell with the addition of water. They have good plasticity & refractoriness and do not possess bleaching properties. China clay results from alteration of Feldspars. Granite, Gneiss & pegmatite are the main source of feldspars. The process of alteration is known as Kaolinisation.The quality of china clay depends much upon the colour, natural fineness. »Mining & Processing   China clay is worked by the open-cut method. China clay found in two modes, residual & sedimentary. Sedimentary deposits having natural purity but residual deposits require to be washed to remove impurities. The most common method of washing is the process of Levigation & Sedimentation. Under this process china clay is mixed with sufficient quantity of water and allowed to flow through different channels and tanks. The heavier particle settle down in Levigating tank and china clay suspended in water flows through different tanksand goes on setting. And after settling the pasty clay is pumped by slurry pumps and fed to filter press and clay obtained in form of cakes, further followed by drying the cakes in sun light.     »Industrial Applications   China clay is generally used for Ceramics, Cement, Insecticides, Paints, Refractory, Paper, Cosmetics, Rubber, Chemicals, Dry cell Batteries, Medicine, Glass industries, Insulators, Textiles.     »Resources in India   India possesses extensive & good deposits of china clay found in almost all parts of country. China clay producing states are Jharkhand, Orissa, West Bengal, Rajasthan, and Gujarat, Andhra pradesh, Karnataka, Madhya pradesh, Maharashtra, Tamil nadu & Kerala. In Rajasthan China clay mainly mined from Alwar, Barmer, Bhilwara, Bikaner, Chittaurgarh, Dausa, Jaipur, Jaisalmer, Jhunjhunu, Nagaur, Pali, Sikar.