Burning and nodulization process of clinker in the rotary kiln as viewed from the fine textures of the constituent minerals.pdfVIP

Cement and Concrete Research 32 (2002) 1039–1044 Burning and nodulization process of clinker in the rotary kiln as viewed from the fine textures of the constituent minerals a,* b c K. Masaki , M. Suzuki , I. Maki a Ube-Mitsubishi Cement Research Institute Corporation, Ube Center Building Materials Group, 1-6 Okinoyama, Ube City, Kogushi, Yamaguchi, 755-8633, Japan bIsolite Insulating Products Co., Ltd., 3-2 Honohara, Toyokawa, 442-0061, Japan cNagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan Received 26 April 1999; accepted 2 January 2002 Abstract Portland cement clinkers from the rotary kiln vary with their grain size in both chemical compositions and microscopic textures, according to the wide variation in the burning and nodulization environment in the kiln. The dense interior of large clinker nodules, first formed at high heating rates on and near the surface of the moving raw mix mass, is enriched with K2O and SO3 and made up from coarse-grained components of the raw mix. The alite crystals consist mostly of the M3 phase with inclusions in the core. By contrast, the porous exterior, formed inside the mass at lower heating rates and firing temperatures, is less in K2O and SO3 content and made up from fine-grained components of the raw mix. The alite crystals are generally zoned with M1 occurring in the core. Clinker nodules of medium size, similar in both the chemical composition and the fine textures of ali