Development of Fused Cast Magnesium Chromium Refractories

In general fired refractories, there are a certain amount of micro-pores and micro-cracks between the refractory materials. These micro-pores and micro-cracks can absorb heat and relieve a part of the thermal stress at high temperatures, but they also It brings some disadvantages, that is, it is very susceptible to penetration and excretion of smelting slag. Compared with the iron and steel industry, the smelting temperature of non-ferrous smelting is relatively low, but the amount of slag is relatively large. The slag is a very corrosive ferrite or silicate. The slag viscosity is low, the interfacial tension is small, and the Infiltration and excretion. Therefore, after the fired refractory is used in the non-ferrous smelting furnace, the permeation and drainage metamorphic layer is relatively thick, and it is prone to damages such as loose layout, strength drop, and spalling. The layout peeling caused by the penetration and discharge of slag is an important reason for the high consumption and low life of non-ferrous smelting refractories. Electric furnace magnesia carbon brick

Compared with the damage mechanism of slag penetration and drainage, fused-cast magnesia chrome brick has peculiar goodness. Because it is a dense frit made by melting, pouring, and group cooling, the slag can only corrode on the appearance of the brick. It is unlikely that there will be signs of penetration and excretion (this has been proved by the judgment of the section of the fused cast magnesia chrome brick after use). Therefore, the production of fused-cast magnesia-chrome bricks is difficult, and the price of magnesia-aluminum-chrome bricks is expensive. In countries with advanced skills, they are still used in key parts of non-ferrous smelting furnaces.

Oxygen-enriched flash smelting and oxygen-enriched bath smelting are now the advanced non-ferrous metal smelting skills in the world; these new smelting skills are characterized by oxygen-enriched blast and intensified smelting. As a result, furnace lining refractories are subject to very harsh use Conditions, the existing domestic refractory materials are still difficult to meet these utilization requirements. While developing and introducing advanced smelting skills, it is also necessary to develop and develop refractory materials used in oxygen-enriched smelting technology, especially magnesia chrome bricks. It is very necessary to digest and absorb the imported skills and accelerate the process of localization.

The production process of fused-cast magnesia-chrome bricks is completely different from the general production methods of sintered refractories. It uses magnesia and chrome ore to add a certain amount of additives and mixed ingredients, melts in an electric arc furnace, casts into a mold, and controls cooling and annealing. Produce master bricks, cut, grind, drill, and cold work to make the necessary bricks.