Experience with the industrial use of refractory concrete

Summary At KMK (Kuznets Steel Combine) extensive tests were made to fit various furnace parts with concrete containing Portland cement and aluminous cement, and also magnesia concretes containing sulfuric-acid bond.The concrete blocks and monolithic linings in a number of places exhibit advantages over brick structures.Concrete blocks behaved successfully in the air heaters, in the walls of heat-treatment furnaces for sheet rolling, in the covers of charging windows of open hearths, in the covers of charging traps of coke batteries, and in the dampers of periodic kilns for firing refractories.Concrete insulation was successfully applied to beam pipes.Experiments to use concrete to line the upper parts of soaking pits of blooming mills were unsuccessful.     

Experience with the use of refractory concretes in structural components of open hearth furnaces

Conclusions Production tests showed that the wear of the blocks made of refractory concretes based on periclase cement and on Portland cernent in the walls of vertical channels, in the back wall and in the front columns of open-hearth furnaces does not exceed the wear of structures of refractory brick.It would be advantageous to continue tests on blocks of refractory concretes in open-hearth furnaces by extending the scale of the trials. The sizes of the blocks should be increased and their weight brought to three tons.For the large-scale use of large blocks of refractory concrete in open-hearth furnaces it is necessary to organize the plant manufacture of all components and to mechanize repair operations.A classification of refractory concretes was given in Ogneupory No. 5 for 1960 and in SNiP part I, section B, chapter 3, p. 11, Gosstroiizdat, 1963 [in Russian].     

Practice of application of refractory concrete in industrial furnaces

The Teploograzhdenie Research-and-Production Company has developed refractory concretes with service temperature of 1150–1650°C which have been successfully used as car bottom lining in tunnel furnaces, block lining of the hearth and lower parts of thermal furnace walls (together with the Termostal’ JSC), lining of roof panels of a continuous furnace, and burner stones. __________ Translated from Novye Ogneupory, No. 11, pp. 18–19, November, 2006.     

Experience with the use of mullite-corundum refractories in the roofs of electric-steel furnaces

Conclusions The resistance of mullite-corundum roof articles, as for periclase chromite, is due to the absorption of melt products from the working region of the furnace and the action of one-sided, high-temperature heating, but in view of the considerable difference in the physicochemical properties the use of the first in the central zone of the roof, subjected to the most severe working conditions, is more desirable than the second.The use of mullite corundum roof bricks, structurally reinforced with nonisometric grains of fused mullite, instead of periclase-chromite refractories will provide an increased roof life, both during the melting of stainless and ballbearing steels, without a change in the structure design; the increase amounts to 25–35%.Translated from Ogneupory, No. 4, pp. 43–46, April, 1986.     

Service of corundum blocks in the hearth of heat-treatment furnaces

Conclusions Prolonged use of the Kor-93 blocks for laying the hearth of heat-treatment furnaces in conditions prevailing at the Donetsk steel factory increased the interrepair period and reduced the outlay of heavy manual work when removing scale.A graph was worked out for drying and warming the furnace in 34 h, ensuring excellent quality of hearths made from Kor-93 blocks.Translated from Ogneupory, No. 8, pp. 29–31, August, 1981.     

Experience with the use of high-alumina and ordinary grog fired in rotary furnaces

Conclusions Grog made of Latnensk clays and high-alumina grog, obtained by firing in rotary kilns have special features producing expansion of ware during firing.The cause of the expansion is associated with the relatively short time for which the material being fired stays in the rotary kiln and the incompletion of the physicochemical processes taking place. Detailed study of the causes of the expansion should be the object of further research by the central factory laboratory of the plant and scientific research institutes of refractories.