FIREPROOF CONCRETE MASSES FOR LINING IN FOUNDRY

摘要

Today, in Russia, carbide - silicon and aluminate - silicate packing masses are generally used for lining blast - furnace chutes. They contain refractory clay, coal-tar pitch and resins as binders which emit carcinogenic substance dangerous for a human organism. Thirty compositions of chute concrete masses excluding any carcinogenic substance were studied and tested on a chute by the Siberian State University of Industry in conjunction with the Kuznetsk Metallurgical Combine company. The best results were obtained with the following composition: 75 % fused electrocorundum, 20 % refractory clay, 5 % high-alumina cement and 7.3 % water (above 100 %). However, in view of the economic crisis and high cost of the electrocorundum, its application is limited. Therefore, we have developed compositions with a high - alumina product (HAP), the waste from the Yurga abrasive works, as a replacement for the electrocorundum. They are as follows: (ⅰ) 35 % HAP, 20 % fireclay powder, 15% refractory clay, 30 % waste from the production of silicon carbide; (ⅱ) 48 % HAP, 20 % fireclay powder, 15 % refractory clay, 32 % waste of silicon carbide with a particle size distribution of 3 to 0 mm. These compositions exhibit < 50 % reduction in strengths (from 80 to 40 MPa) at 1450 °C with other indices (slag resistance, iron resistance, apparent density and shrinkage) being the same as for compositions containing pure fused electrocorundum. Their cost is similar to that of the concrete masses generally used but the service life is 4 times longer which was proved by testing in a central chute of a blast furnace.