The influence of different grain fractions of granulated blast furnace slag to hydration process of blast furnace cement and its properties.

Results of many researches and analysis show, that adding of granulated blast furnace slag to cement increases its properties. Low heat of hydration, sulfate resistance, lower shrinkage in comparison to Portland cement and high impenetrability of concrete made with this type of cement make it a perfect component of all buildings and other concrete constructions which must follow very strict durability requirements.
Traditional way of blast furnace cement production, which is common grinding of both clinker and granulated blast furnace slag in ball mills, allows only to optimize grinding level of final binder or amount of an additive. In such scenario, even significant modification of any of these two parameters enables to shape final products’ features in a very limited range. As a consequence, potential spectrum of application of blast furnace cements because of its unique attributes is narrowed. Separation of slag grinding breaks this limitation and allows to substantial modification of cement properties, which automatically opens the floor to new opportunities.
Current research of chosen grain fractions of slag grinded in ball mill clearly shows differences in phase composition and the structure of granulated blast furnace slag between different fractions, which directly influences hydration process and usable properties of final product. Results prove that grinding method of granulated blast furnace slag is one of the most important factor to determine hydraulic activity of the slag.

Author: M. Oleskow

Section: Science and production

Keywords: waste heat recovery, electric power generation, cement production.