A STUDY ON THE CUSHIONING EFFECT OF CLAY ON THE COMMINUTION OF THE CEMENT RAW MEAL

Abstract

Growth and success of any industry on the whole, depends primarily on the market demands, efficient technology and availability of input resources. In spite of development of different types of binders, cement continues to be the major building material for civil construction all over the world, as no other material is likely to substitute it in the near future. The normal flow sheet for cement production, either by dry or wet operations begins with crushing of the two main components. Either limestone or shale are crushed separately then, ground simultaneously as a mixture (80% limestone and 20% shale) in a ball mill. This procedure consumes more energy in grinding due to the act of the shale as cushions between the grinding elements (balls) and the crushed limestone particles. Consequently, the main objective of this investigation is to evaluate the cushioning effect of the shale during grinding the limestone and shale simultaneously as a mixture. It is confirmed that grinding the two components of the cement raw meal simultaneously as a mixture decreases the specific surface area of the product by 25% approximately. The relative suggestion is to grind these two components of the raw meal separately followed by adding blending unit before going to calciner.