Electrofused bricks have a long production cycle, high power consumption, complex production technology, and are expensive; while sintered refractory bricks have a short production cycle and are relatively inexpensive.
The manufacturing method of fused bricks is a liquid-phase reaction. The melt in the electric furnace is completely liquid. It involves melting a precisely mixed material in an electric arc furnace, then casting it into a sand mold. The casting is then heat-treated, cooled, and processed.
Sintered bricks are solid-phase reactants composed of bauxite and corundum. Since both exist in granular form, mullite is formed at the interface between them during firing. The production process involves pressing the mixture into shape using a mixing press, drying it, and then sintering it in an oxidizing atmosphere at a temperature of 1350-1600 degrees Celsius.
Comparing refractory bricks produced by these two different methods, electrofused bricks have a dense structure, very low porosity, high bulk density, high mechanical strength and high-temperature structural strength, and strong resistance to molten glass erosion. The main products include electrofused mullite bricks, electrofused zirconia-corundum bricks, electrofused chromium-zirconia-corundum bricks, electrofused quartz bricks, and electrofused corundum bricks. Sintered refractory bricks are not as dense or erosion-resistant as electrofused refractory bricks. The main products include clay bricks, high-alumina bricks, corundum bricks, mullite bricks, and composite silicon carbide bricks.
In fused refractory bricks, the various chemical components are fully and uniformly mixed at the molecular level in the liquid phase, and then recrystallize. The crystals are well developed and visible to the naked eye. They are closed pores, so erosion agents do not easily penetrate them. In contrast, sintered refractory bricks have very small crystals that are not visible to the naked eye. They are open pores. Even when using the same chemical composition of raw materials, the difference in crystal phase can lead to a large difference in crystal quality. Because of its simple production process, the selection of raw materials is very important.
