Abstract: A method of treating a kaolinitic clay which is intended for use as an ingredient in a ceramic composition which method comprises the steps of: (a) mixing with the kaolinitic clay from 0.1% to 15.0% by weight, based on the dry weight of the kaolinitic clay, of a smectite clay; and (b) subjecting a mass in a moist plastic state of the clay mixture formed in step (a) to mechanical working under conditions such that there is dissipated in the moist plastic mass at least 5 kJ of energy per kilogram of clay mixture on a dry weight basis.

Abstract: A process for treating a nitride-containing ceramic material which includes the following steps: (1) comminuting the material to produce a particulate ceramic material having a particle size distribution such that at least 40% by weight of the particles have an equivalent spherical diameter (esd) smaller than 2 &mgr;m; and (2) a ferrosilicon separation step comprising one or both of the following steps: a) subjecting the particulate ceramic material produced in step 1 to differential sedimentation in a liquid medium to produce substantial separation of a light fraction from a heavy fraction, ferrosilicon required to be separated being included in the heavy fraction and refined particulate ceramic material being included in the light fraction; b) subjecting a suspension of the particulate ceramic material to magnetic separation to produce substantial separation of magnetic particulate material from non-magnetic particulate material, refined particulate ceramic material being included in the non-magnetic ma

Abstract: A method of improving the strength and/or plasticity of a clay composition comprising a kandite clay and an organic additive comprising at least one water soluble compound having a plurality of basic groups wherein the organic additive is present in an amount of from about 0.05% by weight to about 0.5% by weight based on the dry weight of the kandite clay present, which method comprises treating the kandite clay by adding thereto a monovalent ion activated smectite clay or a monovalent ion activating agent for a smectite clay or both whereby the amount of monovalent ion activated non-calcined smectite clay present in the clay composition is adjusted to be in the range from about 1% by weight to about 5% by weight based upon the dry weight of the kandite clay present.

Abstract: A process is described for preparing .beta.'-sialon comprising heating a mixture of particles comprising from 70% to 90% by weight of particles of an aluminosilicate material and from 30% to 10% by weight of particles of a carbonaceous material at a temperature in the range of from 1300.degree. C. to 1600.degree. C. in nitrogen in a vessel in a manner such that the particles are in substantially continuous motion relative to each other and relative to the nitrogen. The residence time of the particles in the vessel does not exceed 3 hours.