Composite Anhydrite-Slag Binder of Centrifugal-Impact Grinding
Anhydrite binders are an alternative to clinker cement due to the low energy consumption of their production. The basis of these binders is natural anhydrite or anthropogenic productscontaining waterless calcium sulphate. Hydraulic activity of anhydrite is ensured with its fine grinding and the use of hardening activators. As an activator of anhydrite hardening in thiswork, the waste aluminous slag, in chemical composition of which alumina oxide (50-75%) and calcium oxide (15-25%) prevail, are used. It is established that the hardening of thecomposite anhydrite binder is defined by its grain composition and concentration of defects on the particles surface. Ensuring the predominant particlesize of 15 microns with highcontent of surface active centers is reached by grinding of components of the composite binder in a centrifugal-impact mill. Mechanical activation and mechanical-chemical interactionof anhydrite and aluminous slag takes place in this mill. It is shown that when the content of aluminous slag in the composition of composite binder is up to 30%, the content of ettringitein the structure of the artificial stone increases that leads to its strength growth.