DIY Knowledge

Corundum, carborundum

Korund, Karborundum



Corundum is one of the most versatile and frequently used abrasives.
It can be found in most abrasive applications. Corundum is manufactured as follows:
To begin with bauxite is gained from alumina which contains aluminium oxide in relative purity. By calcifying and subsequent melting after the addition of coke and iron filings in an electric arc furnace. After the molten substance has cooled down, the upper layer contains relatively pure aluminium oxide. Depending on the aluminium oxide content you can choose between the white to pink special fused alumina (approx. 99 % Al2O3), brown regular fused alumina (approx. 94?97% Al2O3) and black corundum (approx. 70?85% Al2O3). The desired grain size is obtained by crushing and grinding.