Reportedly, based in Henan, China, Zhengzhou Yufa Group recently develops a kind of new high density corundum material – yellow corundum. This product takes commercial alumina w(Al2O3)=98.96% as raw material and magnesium oxide w(MgO)=89.34% as additive, while the content of the additive is limited in 0-1% and added by dry grinding of ball mill, grinding time must be controlled at 2-10 hours. Next, the mixed materials will be melted for 1-3 hours in electric melting furnace while the melting temperature is controlled in 2100-2300℃, then crush and screen the fused product to get qualified high density corundum—yellow corundum.

the new high density corundum produced by Zhengzhou Yufa Group is yellow, its bulk denstiy is 3.7g/cm3, bigger than ordinary white fused alumina. The company said yellow corundum can be used in high-performance refractories and abrasives industries.