Photomicrographs of Miscellaneous Phases

Photograph 7-88 Dark alkali sulfate deposits on wall of void now filled with epoxy. Coal-fired kiln, wet process. High maximum temperature, long burning time, slow heating rate, quickly cooled, 42 MPa. (S A6706) 

Photograph 7-90 Dark alkali sulfate in clinker void. Prominently zoned alite. Clearly defined lamellae in relatively small, round belite. Low maximum temperature, long burning time, slow heating rate, slow cooling rate, reducing conditions. (S A6708) 

Final polish with mixture of 0.05 pm alumina, isopropyl alcohol, and propylene glycol Field dimensions = 0.21x0.21 mm 

Transmitted, plane-polarized light Field dimensions = 0.14x0.14 mm 

Photograph 7-92 Alkali sulfate deposits (arrow) in clinker voids. Clinker SO3 = 1.12%. Moderately high maximum temperature, moderately long burning time, slow heating rate, moderately slow cooling rate, 

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