GB422238A - Manufacture of cementitious materials - Google Patents

Abstract

A modification of the process for making cement described in the parent Specification consists in mixing limestone and argillaceous or siliceous materials, burning the mixture in a kiln at a temperature sufficient to calcine the limestone but insufficient to cause clinkering of the mixture, adding water to hydrate the lime and mixing and grinding in the presence of a limited amount of water while maintaing a temperature (e.g. from about 100 to 400 DEG C.) sufficient to produce mutual reactions between the lime and the siliceous components and continuing the mixing and grinding until a dry hydraulic cement is produced. The non-calcareous material may be silica sands or siliceous earths and clays, e.g. quartz sand, river sand of vulcanic origin, diatonaceous earth or tripoli, or any argillaceous material generally considered suitable for Portland cement manufacture. Portland cement may be added to the product.