METHOD FOR PREPARATION OF ANHYDRITE BINDER Russian patent published in 2009 - IPC C04B11/05 

FIELD: chemistry.

SUBSTANCE: invention refers to the technology of preparation and application of anhydrite binders based on the anhydrous calcium sulphate. The method includes the disintegration of the gypsum stone, its loading to the conveying lattice and layer burning by the updraft of hot gases from fuel burning with following fine grinding of the calcinated product. The gypsum stone is beforehand diluted with 5-10 wt % of limestone and ground up to the powdery condition. The obtained mixture is moistened with obtaining of the pellets having size 6-8 mm and undergoes the level burning on the conveying lattice with beforehand laying on the lattice of the "bedding" (the layer of calcinated product pellets with thickness 40-60 mm). The 5-8% of oil coke are additionally fed into the mixture of gypsum stone and limestone. Then the pellets layer made of cement raw mixture and oil coke is laid over "bedding" on the conveying lattice and atop of it the layer of pellets made of gypsum stone, limestone and oil coke is laid with ratio of the cement and gypsum layers being 1:1-1.2 respectively. The calcination products of these mixtures are ground up together with 10-12 wt % of the complex additive consisting of 1 part of plastifier and 9 parts of silica component - microsilica or acid CHP-plant ash.

EFFECT: more full raw materials use, simplification of the binder preparation technology, acceleration and cheapening of calcinations process, enhancing of the water stability and resistibility of anhydrite binder.

4 cl, 1 tbl, 4 ex