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The main factors causing wear of the lining of the converters used in nonferrous metallurgy include intensive impregnation of the refractories with the reagents of the converter melt that leads to zonality (zoning) and the corrosive and erosive action of the circulating melt and fluxes. The abrupt and frequent temperature variations occuring during operation lead to the development of stresses in the refractories at the boundary of the impregnated and the unimpregnated zones because of the difference in their coefficients of thermal expansion and to the formation of cracks and splits (chipped surface). In view of this, decreasing the depth of slag-impregnation (penetration) in the lining would improve its life owing to the decreased size of the sheared-off pieces of the refractory and the smaller surface of interaction between the refractory and the slag.It is known that the composition of the finely milled charge has a significant effect on the quality parameters of the magnesic-spinellid (magnesia-spinellide) refractories and on the specific features of their behavior during service [1][2][3][4][5]. In view of this, it is necessary to carry out additional studies on the specific features of structure evolution of the magnesic-spinellid refractories and on the nature of their impregnation and interaction with fayalite slags as a function of the ratio of the chromium ore and sintered periclase in the dispersed constituent (component) of the charge.In order to conduct these studies, we prepared finely milled systems (compositions) based on the chromium ore belonging to the Kempirsaisk deposit and sintered periclase whose chemical composition is given in Table 1.The composition of the finely milled systems was varied from 100% chromium ore up to 100% sintered periclase maintaining intervals of 20%.Using these systems, we prepared charges containing 35% sintered periclase of the 3-1 mm fraction, 30% sintered periclase of the 1-0 mm fraction, and 35% of one of the aforementioned finely milled constituents. Specimens were prepared using a temporary binder consisting of a preheated (up to 30-40"C) solution of technical-grade lignosulfonates having a density of 1.20-1.24 g/cruZ; the compaction pressure amounted to 130 N/ram 2. Firing was carried out in a tunnel furnace at 1700"C maintaining a 4 h dwell at this temperature. Table 2 shows the properties of the fired specimens.In order to obtain a more detailed evaluation, we studied the nature of pore size distribution in the refractories and the specific features of their impregnation with the fayalite slag and their corrosion. Figure 1 shows the differential curves depicting the pore size distribution. Our studies showed that in the refractory containing the finely milled component consisting, entirely, of the chromium ore, the predominant pore size amounts to I0= 100/~m. As the content of the chromium ore decreases in the binder, the number (fraction) of such pores decreases and the number of the pores measuring l-10 ~m increases. The refractory incorporating the peric...

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