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Experiments showed that firing with isothermic holding by interrupting the oxygen blow for 2–5 min is the most efficient mode of firing a converter lining. In this case the depth of the coked layer of the lining in the top part of the cylindrical section reaches 50–80 mm, the decarbonization of the surface layer of the lining is 5 mm or less, and the lining temperature does not undergo steep fluctuations.

The investigation of the thermal expansion hysteresis facilitates, by relatively simple and available means, the obtaining of information about the presence in the ceramic material of active microcracks, that is, those capable of reverse collapse, and about their behavior during thermal cycling of the specimen. The presence of the expansion hysteresis in ceramics containing aluminum titanate exerts a considerable influence on their thermal behavior in working conditions. During thermal cycling of such ceramics in a relatively narrow temperature range (for example, from 700 to 900°C) no changes occur in the microcracked structure, and in this case the ceramic operates in the region of elastic deformations. However, with the expansion of the thermal cycling range brittle failure occurs in the intergrain bonds established at the higher temperature, which leads to the formation, after each cycle of heating and cooling, of a new system of microcracks, which reduce the strength of the bonds between the grains of the ceramic, and in the final account break it up.

The maximum settling of the ground is noted in zone III for transport formation of the dumps (autotransport). Settling of the ground in zones I and II is about the same for different lives of the dumps, that is, during the formation of the dumps by the combined system of working the rocks were more densely compacted in the dump than during the nontransport system.

A technology was developed for the production of zirconia refractories from ZrO2 stabilized with Nd2O3. The thermal strength of the product is adequate for long-term service at a large (200–300°C/mm) temperature gradient. Products based on a zirconia — neodymium solid solution can be used several times.

Batch additives incorporated in the form of various oxides as a means of improving the physicochemical properties of aluminum titanate can be divided into two groups. The first consists of additives which prevent the decomposition of the titanate at temperatures below 1200°C, and stabilize its high-temperature modification. In terms of the degree of activity these oxides are arranged in the series: MgO, TiO2, SiO2, Cr2O3, La2O3. It is possible to assume that their influence is due mainly to the formation of limited solid solutions, and also the development during sintering of impurity grain boundary phases. The second group of oxides (SnO2, NiO, excess Al2O3, etc.) contributes to the sintering of aluminum titanate by forming secondary crystalline phase on the grain boundaries of the ceramic. In this connection in obtaining sintered ceramic materials based on aluminum titanate it is preferable to consider additives of the first group or their combinations with additives of the second group.

Powerful mining-transport equipment designed for operating the second phase of the Novoraisk Mine should be used for carrying out the mining-capital work, and this will reduce the time required for bringing the second section of the mine on stream. Preliminary preparation of the tracks for the cut-out channels (removing the black earth and the potentially useful bed) will afford the possibility in the initial period of building and resolving the problems of mining-engineering stages of recultivation. The proposed combined scheme for cutting out the channels will facilitate drying out of the section during the building of the quarry.

Chamotte packing masses containing finely milled pyrophillite and aluminochromophosphate bonding can be effectively used for the manufacture of heat-insulating linings operating at 1200–1300°C. Because of the higher thermal-shock resistance, it is most sensible to use them in the manufacture of linings which operate in cyclical heat regimes. The addition to the packing masses of pyrophillite and water glass limits their operational temperature to 1000–1100°C.

Mining-engineering recultivation is a link in the common chain of the technological process of mining fireclays. The proposed technological scheme for carrying out overburden work will allow separate extraction of the materials, and replacement of the potentially useful soils on the surface of the dump.