Systems and processes for pyrolyzing contaminants on foundry sand and combustion of the resulting gas

摘要

Foundry sand in roasted in a rotatable container to remove organic contaminants by: (a) feeding the sand into the container, then adjusting the position of the container so that the axis is at an angle of between O to about 10 degrees from the horizontal; and (b) rotating the container and sand contents about the axis, whilst firing with at least one burner flame having excess oxygen in the container, the flame directed at an angle of between O and about 30 degrees from the horizontal to burn off the contaminants and produce an off gas containing oxygen and foundry sand. Also claimed is a combustion process similar to the claimed process above using a rotary kiln to roast the foundry sand. A combustion system is also claimed including a rotary kiln, and further processing equipment for the resultant sand and offgas.