Low carbon magnesia carbon brick and preparation method thereof

Abstract

The invention relates to the technical field of magnesia carbon brick refractory materials, in particular to a low carbon magnesia carbon brick and a preparation method thereof. The technical proposal comprises the following steps: mixing 58 to 70 weight percent of magnesite grains, 20 to 28 weight percent of magnesite fine powder, 0.5 to 5 weight percent of expansion graphite, 0 to 6 weight percent of crystalline flake graphite, 1 to 5 weight percent of antioxidant, 0.1 to 5 weight percent of metal fibre and 1.5 to 4.5 weight percent of phenolic resin; and molding and drying the mixture to prepare a low carbon magnesia carbon brick of which carbon content is between 2 and 7 percent. The low carbon magnesia carbon brick prepared by the invention has the advantages of low heat expansion rate, good scale resistant performance, good high temperature strengthen, good thermal shock resistant performance, good toughness and corrosion resistance, and the brick is not easy to fracture when using.

Description

Technical field: [0001] The invention relates to the technical field of magnesia-carbon brick refractory materials, in particular to a low-carbon magnesia-carbon brick and a preparation method thereof. Background technique: [0002] A low-cost raw material smelting stainless steel technology "GOR gas-oxygen smelting technology" from Russia, Ukraine and other countries has been successfully adopted by some domestic iron and steel enterprises. GOR converter is a bottom-blown converter with multiple energy media composite blowing. The furnace bottom lining bricks are generally made of magnesia-calcium bricks or magnesia-chrome bricks. There are only a dozen heats or dozens of heats, and the highest is only about 50 heats, which directly causes many losses and cost increases to iron and steel enterprises, and affects the normal smelting of stainless steel. The existing ordinary magnesia carbon bricks generally have a carbon content of 10-18%. When used as a furnace lining, alth...

AI Technical Summary

Problems solved by technology

GOR converter is a bottom-blown converter with multiple energy media composite blowing. The furnace bottom lining bricks are generally made of magnesia-calcium bricks or magnesia-chrome bricks. There are only a dozen heats or dozens of heats, and the highest is only about 50 heats, which directly causes many losses and cost increases to iron and steel enterprises, and affects the normal smelting of stainless steel.

The existing ordinary magnesia carbon bricks generally have a carbon content of 10-18%. When used as a furnace lining, although the thermal expansion rate is low and has good spalling resistance, the carbon content of stainless steel molten steel will be increased during the smelting process, which will affect the quality of stainless steel; Low-carbon magnesia-carbon bricks contain less carbon, and generally the carbon content is ≤8%. Although it will not affect the carbon content in stainless steel water, the thermal conductivity of the brick is small and the thermal expansion coefficient is large, which leads to an increase in the thermal expansion rate during the thermal working process, resulting in Thermal spalling, reduced thermal shock resistance, fracture, accelerated erosion, etc.