After mining, the porcelain stone and Kaolin usually go through the processes of porphyrization, washing and others before they are made into Dunzi and moved into the biscuit house for clay formulation. The Dunzi cannot be directly used to make porcelain body and glaze. They need to be refined, processes and compounded before they are fit for bodies and glazes of various wares. After washing, the coarse particles will be removed from the raw materials. In accordance with the traditional experiences in Jingdezhen, the control of degree of fineness depend upon the control of the amount of clarifying water in vats and the amount of water scooped out of the vat.
However, as for the clay used to make large wares such as jars and basins, it is not necessary to repeatedly to repeatedly wash and clarify in order to have coarse particles in it. Having a less component of flux and a proper proportion of fine and coarse particles, this coarse clay is obviously good for reduction of drying and firing shrinkage to prevent wares from being deformed or cracked. It is suitable for making of large wares. |
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