Ball Clay

Ball clays are remarkable because of their high plasticity when mixed with water. The plasticity is a result of fine particle size (0.1-1 pm), which is stabilized by a substantial content of organic matter (up to 2 wt%). Typical compositional data for ball clays are given in Table 5 [24]. Because of the fine particle size, the water demand for ball clays is higher than for most china clays. The fine particle size also gives ball clay bodies higher green strength and higher fired strength than other clays. In the raw state, ball clays range in color from light brown to nearly black, depending heavily on the organic content. After firing, the higher Fe2O3 and TiO2 contents give ball clays, compared to china clays, an ivory to buff color. Ball clays are used extensively in whitewares, pot­tery, and traditional ceramics due to the workability and strength. However, their use in hard porcelains or other applications where color is important is minimal.