GEOPOLYMERS OBTAINED BY MECHANICAL ACTIVATION OF ORIGINAL COMPONENTS: REVIEW OF CURRENT TRENDS

Abstract

The reaction potential of a substance can be significantly increased by thermal, mechanical, and chemical methods. A combined method is also possible, as in the case of developing geopolymers, the technology of which involves treating precursors with chemical reagents. On the other hand, with the increase in the number of publications devoted to the development of geopolymers, research to reduce the amount of CO2 emissions and the cost of geopolymers production becomes relevant. This review examines three generations of geopolymers: 1 – metakaolin based geopolymers, 2 – geopolymers based on rocks, and 3 – fly ash based geopolymers. A comparative analysis of ways to improve the physical and mechanical properties of fly ash based geopolymers by mechanical activation is presented. It has been established that mechanical activation of fly ash, in addition to improving the strength characteristics of geopolymers, makes it possible to synthesize a geopolymer without thermal curing. After this, the focus is on the method of mechanical activation of fly ash and clay minerals, especially kaolinite. The particular interest in metakaolin based geopolymers is due to the high potential for widespread application, since these geopolymer technologies have greater potential to reduce CO2 emissions and, therefore, production costs. Also, the development of protection against heavy metals or radioactive substances requires the implementation of technology exclusively using geopolymers based on metakaolin.