Smelting methods of Brown fused alumina
There are three main smelting methods for brown corundum smelting: fixed furnace frit method, dumping furnace smelting method and exile smelting method. Due to the large scale of investment in exile smelting, currently my country mainly adopts fixed furnace frit method and dumping furnace smelting method.
Comparison of corundum products made by different methods:
1. The corundum produced by dumping furnace (method) has many crystal aggregates, small crystal size, high glass phase and distributed on the grain boundary, so it has poor toughness, high brittleness, good abrasive grains easy to fall off, good self-sharpness and good compactness. It is more suitable for consolidating abrasive tools and refractory materials.
2. The corundum produced by the frit furnace (method) has less crystal aggregates, large crystal size, and less glass, so it has poor brittleness, high toughness and good wear resistance. Due to the large crystal size, toughness and brittleness, the brown corundum produced by this smelting method is more suitable for the manufacture of coated abrasives. Therefore, it is still the most used abrasive in abrasive belt production.
3. The chemical composition, phase composition and specific gravity of the corundum produced by the flow method smelting method are equivalent to those of the frit method. The crystal size, microhardness, crystal structure and compressive strength of the exile method are slightly lower than those of the frit method. This is because the brown corundum produced by the exile method has the characteristics of microcrystalline corundum in these aspects. Although it is slightly lower than the frit method, it shows better results in use.
