Hi everyone,
In my country, the price of gypsum is very high, higher than clinker. So i want to use a little big limeston to replace a little big gypsum so that i can reduce the production costs.But this repalcement must keep the setting time of cement in the same with before. Someone who can solve this problem, pls teach me how can i do it !!!
Thanks and Regard
Cement Vi?t
Hello CVM,
Several researchers (eg Bensted & Kantro) have claimed that while limestone cannot be used as a total replacement for gypsum, it is possible to replace a portion of the gypsum with limestone without significant problems with cement performance. They suggest that, due to the mitigating effects of limestone carboaluminate reactions, up to 25% of the gypsum could be replaced with limestone without any significant change to setting times or strengths.
You would have to do plant trials by incrementally increasing the limestone content and decreasing the gypsum content in small steps to see how far you could take this replacement in your cement.
References:
1. "Limestone Substitutes for Gypsum as a Cement Ingredient", G.S. Bobrowski, J.L. Wilson & K.E. Daugherty, Rock Products, Vol.60. No.2, 1977 pp. 64-57.
2. "Some Hydration Investigations Involving Portland Cement - Effect of Calcium Carbonate Substitution of Gypsum", J. Benstead, World Cement Technology, Vol.11, No.8, 1980, pp.395-406
3. "Calcium Carbonante Additions", D.L. Kantro, 1980 Cement Chemists' Seminar, Portland Cement Association, Skokie, IL 1980.
Regards,
Ted.
Dear Ted!!!
Thank you so much for your help !!!