The main differences between sintered tabular alumina and fused alumina are as follows:
1. Sintered tabular alumina has low impurity content and is evenly distributed, while fused corundum has high impurity content and is unevenly distributed. Sintered tabular alumina uses high-purity industrial alumina as raw material, and no additives are added during the production process. Except for a small amount of mechanical iron entering during crushing (which can be removed by a magnetic separator), other impurities such as iron, silicon, and sodium are all trace amounts.
During the production of fused alumina, iron and carbon need to be added as additives. The impurity content of iron, carbon, silicon, sodium, etc. is much higher than that of sintered tabular corundum. At the same time, due to the different cooling speeds of different parts of the fused corundum molten block during cooling, the impurity content of different parts is different. Therefore, fused corundum emphasizes strict selection, while sintered tabular alumina does not need to be selected.
2. Sintered tabular alumina has better thermal shock and spalling resistance than fused alumina. Sintered tabular corundum has better thermal shock and spalling resistance because it has a large number of closed pores. Spherical closed pores can effectively resist thermal shock and prevent the spread of cracks.
Fused alumina has more open pores and fewer closed pores, and it forms larger single crystals during a slower cooling process. These single crystals produce microcracks during the crushing process, thereby reducing the thermal shock and spalling resistance.
3. The production process of sintered tabular alumina is far more energy-efficient and environmentally friendly than that of fused corundum. Fused alumina production is well known to be a high energy consumer, consuming 2300-3300 degrees of electricity per ton of fused corundum, while the comprehensive energy consumption of sintered tabular corundum is only one-seventh to one-tenth of that of fused corundum.
The production process of fused alumina emits a large amount of waste gas and waste slag, while the production of sintered tabular corundum uses natural gas as the heat source. In addition to the carbon dioxide emissions in natural gas, there are no other waste gas and waste slag emissions.
