Effect of cooling performance on the mineralogical character of Portland cement clinker

The mineral compositions, crystal features, and microstructures of the low- quality cement clinker from a cement plant were investigated with X-ray dif fraction,, scanning electron microscopy (SEM), and reflected light microsco py. X-ray diffraction shows that the clinker contains additional phases (C( 12)A(7) and alpha -C2S) besides the four normal minerals [alite (C3S), beta -C2S, ferrite (C(4)AF), and aluminate (C(3)A)]. Microscopic observations i ndicate that there are microcrackles on belite (C2S) crystal surfaces, leaf like texture of C2S aggregates, and droplets of crystalline black interstit ial minerals, which suggest the clinker was produced under reducing conditi ons and underwent a rapid cooling process. (C) 2001 Elsevier Science Ltd. A ll rights reserved.