Batches of a container-type composition were melted in an electrically heated furnace for 3-4 hours. Additions of sodium sulphate to the batch were made, ranging from 0-10 parts sulphate per 1000 parts sand. The melts were made in furnace atmospheres of air, nitrogen, nitrogen and carbon monoxide, nitrogen and sulphur dioxide and air and sulphur dioxide. It was found that additions of sulphate of less than 5 parts per thousand sand made no contribution towards improving fining and in some cases had a deleterious effect. Above this level of sulphate addition there was a marked improvement in fining.
Origin
Bgira
Journal Title
Am Ceram Soc Bull 45 11 1966 1004-1008
Sector
Primary Papers
Class
PP 73