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Results of a study of the heat resistance of chamotte refractories as a function of the composition of their binder are presented. The introduction of a refractory particolored clay or clay DN2 rich with alkaline and alkaline-earth oxides into chamotte-kaolin mixtures hampers the formation of cristobalite. The cristobalite effect and the temperature coefficient of linear expansion of the specimens decreases up to a temperature of 600°C, which enhances their heat resistance

An experimental lot of special- and general-purpose grog refractories was fabricated. Mottled clay was added to the mix to enhance the density and strength of the ware. Properties of experimental and commercial products are listed. It is shown that mottled clay can well be used instead of plastic clay in the manufacture of grog refractories from Vladimirovka kaolin.

It is proposed to use mottled clay, which occurs in the overburden, as a way of improving the sintering of Vladimirovka kaolin. Some properties of the clay were investigated. It was found that the beneficiation of mottled clay improves its sinterability. A study is reported into how the mottled clay content of kaolin affected its sintering. An optimal way to prepare mottled clay would be to beneficiate it and to intergrind it with grog.

A laboratory study aimed at replacing expensive chamotte from Chinese bauxites used in a ramming mixture by disthene-sillimanite concentrate is described. It is shown that partial replacement of the chamotte by disthene-sillimanite concentrate can give the required high-alumina ramming mixture.