With six to seven melts per day and a lining t e m p e r a t u r e of not less than 600~ w e a r takes place by fusion of the working zone, not by cracking, as noted above. In this connection the lining structure is monolithic with a glazed surface. With this intensity of operation the variation of the lining wear is determined by the chemical composition of the stag.With six to seven melts per day (_46% of the campaigns) the ladle lining durability after hot patching was 28 melts, with a maximum of 37 melts, as compared with 17.1 for ladles without hot patching and from one to two melts per day. Thus the use of a r e f r a c t o r y dressing for patching local sectors of wear reduces the number of intermediate maintenance operations.Over a test period of 2 months with 1.58 hot patchings per ladle campaign, the durability was increased on average from 19.1 to 23.3 melts, with a r e f r a c t o r y consumption of 5.4 kg/tou of steel as against 6.3 kg/ton without hot patchings. Figure 3 shows the variation of the lining durability over a period of years. CONCLUSIONSThe use of 70-75% of silica artifacts to line steel-teeming ladles, accompanied by routine hot patchings, has permitted an increase in the lining durability by from four to five melts.With an increase in the ladle throughput from 1-2 to 6-7 melts per day, accompanied by hot patchings, the maximal lining durability was 37 melts (average 28 melts) and the refractory consumption was reduced by 2.1 kg/ton of steel.The saving obtained by the use of a silica lining was 332,200 rubles. INTERACTIONOF PERICLASE AND CORUNDUM REFRACTORIES WITH IRON AND IRON--MANGANESE MELTS

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Recent years have seen a constant increase in the amount of steel poured through sliding gates, the principal component of which is perielase and corundum plates; this calls for an investigation of the resistance of these types of refractories to metals. Their reaction with highly oxidized melts was examined in a previous communication [1] showing that it is determined by the properties of the primary oxide phase of the melt (POP), consisting of iron and magnesium oxides.Melting of killed steel with minimal oxygen content involves the use of deoxidizer elements with a high affinity for oxygen; this significantly changes the composition of the POP and the character of its action on the refractory. To cover the range of typical POP compositions, and therefore the possible routes of the reaction of the refractory with steel, the investigations were performed on metal deoMdized with ferrosilicium (tacit A), ferrosilicium and ferromanganese with a ratio [Si] : [Mn] in the steel greater than 2 : 1 (B), ferrosilicium and ferromanganese with a ratio [Si]: [M_n] in the steel lessthan 1:2 (C), andferrosilicium, ferromanganese, and aluminum, the proportion by weight of the latter being up to 0.1% (D).