How to judge white fused alumina quality grade?

White fused alumina sand & powder are both made by crushing and sorting large pieces of smelted white corundum. It is difficult to distinguish the quality from the appearance of WFA sand and powder. However, we can judge white fused alumina quality grade from the appearance of WFA blocks.

Usually, white fused alumina blocks melted from fixing furnace and tilting furnace. Firstly, the white aluminum oxide fused in a fixed furnace has a dark color.  The WFA blocks near the furnace wall, low alumina content has more impurities. Those blocks are not suitable for as a primary block for subsequent sand making and micro powder production of white fused aluminum oxide. The cost proportion of fixed furnace white corundum is low and the rejection rate is high. So the cost is also high. However, the physical and chemical indicators of purity and hardness of the fixed furnace white fused alumina are better.

Low sodium white corundum is also smelted in a fixed furnace, with a more unique formula. The resulting white corundum blocks have a darker color, a denser texture, and a higher specific gravity. It can be clearly seen from the appearance that there are very few pores.

Secondly, the tilting furnace white fused alumina has a straightforward color. All parts WFA blocks can enter the next production process, so the cost is low. However, the impurities are dispersed in various parts of the white corundum, and the content of alumina is not as high as that of the fixing furnace WFA. In the meantime, the grinding ability and fire resistance are not as good as White fused alumina from fixed furnaces.