Refractories are an important design material in the construction of blast furnaces.In analyzing the resistance of refractories in the lining of blast furnaces it is necessary to take into account not only the quality of the articles but also the design features of the lining and its exploitational conditions.In such an approach we can discover the objective factors causing the destruction of the lining and can select the best ~ays of improving its resistance.In the current Five-Year Period and up to 1990, the construction of blast furnaces of a volume of 3200 to 5000 m 3 or more is planned.It is well kno~n that the life of the linings of different sections of the blast furnaces varies over wide limits.The life of the linings of the shaft and bosh parallel is between 2 and 12.5 years with an average of 5.2-5.4 years, while the life of the refractories in the hearth and hearth bottom is 5 to 22 years with an average of 14-17 years.Therefore, in the next few years it is necessary to concentrate attention on prolonging the life of the linings of those sections of the furnace which show intensive damage.In the case of the linings of the shaft and bosh parallel, dense and high-density chamotte refractories are normally used.In some cases the bosh, bosh parallel, and shaft are lined with silicon carbide refractories in nitride and oxynitride binders, mullite, corundum, corundum--chromite, spinel, semigraphite, and other products.During service the most rapidly damaged sections of the refractory lining of blast furnaces are the cooled regions of the shaft, bosh parallels, and bosh, the tuyere zone, the regions of tile iron notches, and the upper part of the hearth bottom.The uncooled region of the shaft in most cases is lined with a compacted chamotte refractory with a porosity <17%.This part of the lining, of course, is little corroded and is not always replaced during the major overhaul of category II blast furnaces.The cooled region of the shaft, bosh parallel, and boshes are lined with dense chamotte refractories with a mass fraction of 39-42% A1203.The most intense damage to the refractory lining of the shaft is found in the region of the lower rows of coolers. Therefore in the lower part of the shaft, bcsh parallel, and boshes, dense kaolin articles with a porosity of 8-12% are used; the latter are produced at the Chasov-Yarsk Refractory Combine.Blast furnaces are operated over practically the whole period with the same fittings in the bosh parallel, the cooled part of the shaft, and the boshes.The tuyere zone is lined with chamotte or sometimes with mullite or mullite--corundum refractories.To line the well, carbonaceous blocks mainly are used, and in the openings of the iron notches, dense chamotte, mullite, or mullite--alumina refractories and sometimes carbonaceous.The upper part of the hearth bottom is made in the form of a combined lining of carbonaceous m~d mullite blocks, or only carbonaceous blocks.The damage to the lining in this region of the furnace occurs because a new surface appears on the blocks as...

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