Calsintering

Name:
Calsintering
Detailed information:
A method for recovering alumina from fly ash developed in 1978 by Oak Ridge National Laboratories. The essential steps are pelletizing and sintering a mixture of fly ash and lime (from either limestone or gypsum) at 1000–1200C for 20 min. The product is ground to 40 mesh and leached with dilute sulfuric acid. The leached solution is then solvent extracted, crystallized, and calcined to alumina, which then can be converted to aluminum by standard methods. The high recovery of alumina suggests that fly ash is a viable alternative raw material for aluminum.