1. Silica
Silica is a material widely used to make ceramic objects, glaze, glass, etc.. This material does not have the properties of the plastic so that when used to make ceramic body will reduce the level of plasticity and depreciation are used to add capabilities to shape and hardener, while the glaze serves as penggelas.
Melting point is 1710 ° C. Silica Quartz is another form of silica which has a purity of 100%. Silica or quartz can be found in the oxide material called silicates such as kaolin / china clay, feldspar, nepheline syenite, lepidolite, petalite, spodumene, pyrophylite, claydll ball.
Another form of silica is flint, this material is widely used to make ceramic objects, has a high purity. Precipitated silica found in nature are usually mixed with various ingredients impurities (impurities) that would affect its properties both in the raw state or after combustion.
Usefulness of silica: plasticity menguarangi reduce shrinkage reduces cracks in the drying process. increase the ability of an order form and hardener during combustion.
reducing the cracks (crazing) in the glaze.
2. Feldspar
Resulting from the weathering of feldspar granite and lava rocks (igneous) which was formed clay, feldspar including alumina silicate compounds containing one or more elements such as K, Na, Ca. As the material is not plastic, feldspar is very important in the ceramic industry as it can serve to reduce shrinkage during drying and firing process, also serves as a flux (melting) at temperatures above 12000C. Melting point between 11700C-12900C. Feldspar is very useful in the manufacture of ceramic objects glassware, stoneware, porcelain, as well as materials to make the glaze.
Feldspar is composed of various types, namely Potash feldspar (K2O Al2O3 6SiO2) Sodium feldspar (Na2O Al2O3 6SiO2). Judging from the elements mengadung feldspar material alumina (Al2O3), silica (SiO2), and fluxes (K2O or Na2O), which contains potassium (K2O) is usually used for making fine ceramic body because it is very active dissolving quartz, shaping the glass very thick, and as a good fuser in fine ceramic body so dense ceramic body into shape without undergoing change (deformation), while the other contains a lot of sodium (Na2O) to make a glaze.
Whiting (Calcium Carbonate) (CaCO3) Whiting used a mixture of clay burnt at low and medium temperatures. Whiting (calcium carbonate) serves as a flux, ie to lower the combustion temperature, a small amount is used as an ingredient in the glaze buster. Elements Ca (calcium) contained in the whiting widely used in ceramic body because it can lower the melting point, membenkan white color and prevent arcing. Ca can act as a flux at low temperature. With zinc in the glaze will form pemiukaan matt (dof), due to crystallization.
3. Dolomite
Dolomite is a material combination of calcium carbonate with magnesium carbonate which serves as a flux or lowering the temperature in a mixture of clay, this material including plastic materials.
4. Aluminium (Al2O3)
Elements of aluminum oxide (alumina) is not found in its pure form, but in combination with other elements, especially in the kaolin, ball clay, and feldspar. Alumina is a highly refractory material and the material is very stable both physically and chemically.
In glaze aluminum serves to control and compensate for melting and give strength to the ceramic body and glaze, is in the ceramic body to increase viscosity, melting point prevents crystallization and stabilize the glass mass. In the plastic mass of ceramic, kaolin element will give Al2O3 plastic but not quite pure, while ball clay will give the plastic but not pure Al2O3.
5. Talc
Talc is a mixture of magnesium silicate having the chemical formula hidrosid 3MgO 4SiO2 H2O, serves as a flux (melting) at low and adding a burnt glaze adhesion on ceramic body and prevent the onset of cracking in the glaze. Talc is widely used as filler (filler) and cover material on some kind of ceramic industry (especially for walls and porcelain of China), this was due to the ceramic bodies containing talc would be very resistant to sudden changes ternperatur pngembuatan widely used for power tools , cooking ware, kapsel, aids combustion (refractory), also in ceramic art and ceramic bodies burnt low.
6. Nepheline syenite (SiO2 KNaO.Al2O3.4)
Nepheline syenite is a ceramic mineral that can be used as a substitute for feldspar. Nepheline syenite containing silica (SiO2) and alumina less (Al2O3) is higher than the feldspar. This material can be used to glaze Earthenware or stoneware, glass-making materials as a source of Al2O3.
7. Grog
Grog is tana h clay material that has been burnt biscuits and then finely ground, having fine to coarse grain. Grog is widely used to make ceramic body especially the larger ones, grog serves to reduce the plasticity and shrinkage so as to protect objects to deformation. With the grog cause the body to become more porous ceramic objects, but with this condition allows evaporation, also prevent the occurrence of cracks in the drying process and combustion, resistant to sudden changes in temperature, as well as providing a rough surface texture. .
Figure 6.19. Ceramic materials are not plastic.