The furnace bottom carbon bricks are mullite bricks, the furnace side walls are made of corundum large prefabricated blocks or theron-fused corundum bricks, and the furnace cores are made of high-quality carbon bricks or microporous carbon bricks; the furnace bottom and furnace hearth refractory materials are mainly Use large carbon bricks.
(2) Tuyere area and furnace belly
The tuyere area and the hearth are the hottest areas in the blast furnace. The high-temperature gas produced in front of the tuyere rises at a very high rate, and its temperature is above 1600 centigrade. High-temperature hot metal and slag from 1450 to 1550 centigrade flow through the belly to the hearth. Various metallurgical reactions proceed vigorously in this area. This area requires refractory materials to withstand high temperature, slag corrosion, good alkali resistance, carbon dioxide and water oxidation resistance. . The refractory materials used in this part are: corundum brick, aluminum carbon brick, hot pressed semi-graphite carbon brick, SiC brick, Si3N4 combined SiC brick, Sialon combined SiC brick, Sialon combined corundum brick.
(3) Lower part of furnace waist and furnace body
The lower part of the furnace body of the furnace waist is where the root of the blast furnace reflow zone is located, where the temperature is high, but it does not form a slag skin or form a stable slag skin "self-protection". Refractory materials undergo severe temperature fluctuations, erosion of initial slag, erosion of alkali metals, zinc, erosion of high-temperature gas streams, wear of descending charge, oxidation of carbon dioxide, water, erosion of carbon monoxide, etc., requiring thermal shock stability of refractory materials Good, high temperature resistance, good alkali resistance, strong resistance to slag erosion, oxidation resistance, wear resistance, thermal conductivity. At present, this part can continue to work for more than ten years, mainly due to the control of edge airflow and enhanced cooling. Relatively speaking, aluminum-carbon bricks, SiC bricks, Si3N4 combined SiC bricks, Sialon combined SiS bricks, Sialon combined corundum bricks, etc. have better use effects.
(4) The middle and upper part of the furnace body