Mechanochemical activation of natural and technogenic raw materials in the production of high strength plaster

Abstract

Currently, the growth of production of gypsum materials and products exceeds the economic growth of the world markets. More than 90% of binder manufactured of natural raw materials is produced of low grades, and, for production of high strength gypsum by crushed stone autoclaving, not more than 40% of extracted raw materials are used. This is due to low percentage of crushed stone of required fractions (larger than 30-50 mm) is produced from the rocks by crushing and classification. The accumulated industrial experience showed that further development of production of high grade gypsum binders is possible provided it is subject to a substantial reduction of technology, increase of productivity and reduction of fuel and energy consumption. A technology of production of gypsum binders of small fractions of gypsum rock and phosphogypsum by mechanochemical activation (MOSS) of raw materials is proposed and developed. Advantages of the suggested technology: 1. In production of high-strength gypsum binders the technology allows complete processing of raw materials, including fines generated during crushing (fraction smaller than 5 mm); 2. By changing the maximum grain size and application of MOSS, total time of heat processing (autoclaving and drying) is reduced by 2.5 – 3.04 h, which allows reducing fuel and energy consumption; 3. Operation of binder grinding after drying is excluded.