A potential of chromium (VI) reduction in commercial clinker burning

This is a study of the clinker firing methods used for chromium reduction in industrial facilities. With that end in view, either the charge of secondary fuel and/or the point of introducing this fuel into the rotary kiln were changed. Since in the course of tests the total chromium content in the clinker was not constant, the extent of chromium reduction was assessed by the ratio between the chromium (VI) (or its soluble part) content and the total chromium content. The soluble chromium (VI) content in the clinker was intentionally changed thus affecting the kiln operation procedure. In particular, introduction of secondary fuel into the clinker stream in the rotary kiln cooling zone reduced the soluble chromium (VI) content in the clinker.

Author: K. Shimosaka, E. Asakura, H. Tanaka, M. Yamashita

Section: Science and production

Keywords: Portland cement clinker; burning, secondary fuel; reducing atmosphere; total chromium; total chromium (VI); soluble chromium (VI); chromate; chromium reduction (VI); stabilized soils