Pilot scale production of limestone calcined clay cement

Abstract

Limestone Calcined Clay Cement (LC3) was produced on a pilot scale in a cement grinding unit. Raw clay was obtained from mines in Gujarat. Raw material that was otherwise unusable in applications like paint and paper was found to be suitable for the production. While most of the calcination of clay is being carried out using furnace oil and bio-mass, even petcoke was found to be suitable for application to LC2 to achieve cost reduction. Quality control was carried out using XRD, TGA and visual observation and the clay was carefully sorted into batches based on the test results. LC3 and LC2 were produced by inter-grinding the raw materials and a normal ball mill was found to be adequate for the production process. The test results showed that while Blaine’s fineness test may be a good initial measure to control the grinding process, due to differential grindability, laser diffractometry can provide a better assessment of grinding of all components of the cement. It was found that both LC3 and LC2 can be produced using widely available technologies with very little modifications. Physical tests on LC3 and LC2 were carried out and both were found suitable for general applications and some special applications.