FEATURES OF FORMING CONSTRUCTION PRODUCTS USING SULFATE SLAG BINDING COMPONENTS

Abstract

The availability of raw materials in certain regions allows to accelerate the pace of construction of multi-storey buildings and individual townhouses. The absence of mineral and building materials facilities gives impetus to the development of new structural materials. Sulfate-slag binders (SSB) are one of the types of binders that are characterized by low CO₂ emissions during production. The main raw material for them is blast furnace granulated slag (75...85%), gypsum or anhydrite (sulfate activator) is used to activate the hardening of the slag in an amount of 10-20%, as well as up to 2% calcium oxide or 5% Portland cement (alkali activator). As a result of the interaction of these components, a stone is formed, consisting mainly of ettringite and calcium hydrosilicates. An additional advantage of SSV is the possibility of using as a sulfate component of phosphoanhydrite binders (PAB), obtained by calcination of phosphogypsum (PG) - one of the most large-tonnage wastes of the production of orthophosphoric acid and fertilizer from phosphate rocks, the annual volumes of which are estimated at hundreds of millions of tons worldwide. Differences in the properties of phosphogypsums of different industrial enterprises, which are determined by the type of phosphate rock and the technological mode of its processing, which will affect the processes of structure formation of SSV.

In this regard, the development of rational compositions of sulfate-slag binders and commercial products based on them, taking into account the genetically determined structural-morphological and physical characteristics of phosphogypsums and PAB obtained from them, is an urgent task, the solution of which will allow increasing the percentage of utilization of PG, reducing environmental pressure and expanding the mineral industry.