The effects of excess sulfur on clinker properties

It has long been known that excess sulfur in clinker can lead to operational changes in the pyro-processing system. Excess sulfur will also create changes in the finish grinding system. Not only can the sulfur content change the clinker size distribution, but changes in clinker chemistry can have effects on cement quality. Recent industry trends are pushing toward increased burning of alternative fuels such as pet coke, liquid and solid waste products, etc. that have uncommon chemical compositions. Pyro-processing technology has been advanced to handle these fuels. In order to fully take advantage of these developments, a fundamental understanding of the effects of excess sulfur on the cement product is necessary. This paper will discuss the clinkerization process as it pertains to clinker microstructure, its subsequent effect on clinker grindability and product quality related issues as they pertain to increased sulfur levels. Results of a study conducted in an operating plant will be used to compare the changes observed in the grinding department as well as analyze the effects on cement quality and document the improvements and detriments when clinker with various excess sulfur levels is produced.