Molecular study of thermal immobilization of chromium(VI) with clay.

Clay that contains kaolinite has been used extensively as a raw material for manufacturing of bricks and china at 900-1100 degrees C. This study used clay to stabilize the contaminant chromium(VI) [Cr(VI)] through a heating process at 500-1100 degrees C. X-ray absorption spectroscopic results indicated that the 500-900 degrees C heating process transformed hazardous Cr(VI) to nontoxic Cr(III); Cr2O3 was the species detected as most abundant.