Sawing of blocks of siliceous dimension stone: influence of texture and mineralogy

Abstract

The sawing of granite blocks using multi-blade gangsaws and an abrasive mixture is one of the most complex operations in the rock transformation industry. The surface quality of the finished slabs is the major determinant of the volume of material to be removed in subsequent polishing operations, thus influencing the final cost of the product. To determine this quality, a portable piece of equipment which records direct measurements of the roughness of the slab surface was developed. The measurements were carried out on two types of granite slabs of high commercial value. These granites showed mineralogical similarities, but great differences in cutting speed and the cost of the industrial process. The paper discusses the results in relation to Knoop hardness, Amsler wear, deep abrasion and petrography and concludes that the texture of the rock has the most important influence on the cost of production of polished slabs.