Complementary use of industrial solid wastes to produce green materials and their role in CO2 reduction

Abstract

Abstract Sulfoaluminate cement (SAC) is a quick-repairing engineering material, and it has advantages of an early strength, rapid hardening, and more importantly, a low sintering temperature. In the conventional SAC industry, natural gypsum, bauxite and limestone are used extensively as the main raw materials, which requires more natural-resource consumption, and emits greenhouse gases. Our group developed a novel technology to produce SAC green materials by using industrial solid waste (ISW) as raw material. The major mineral phases of the SAC green-materials clinker were C 4 A 3 $ and C2S, the main hydration products were a C–S–H phase and AFt crystals, and the microstructure was dense. The hydration products had excellent mechanical properties; their compressive strength reached 75 MPa after 3 days of curing. To enhance the ISW value-added, three-dimensional printing materials, foam concrete block and high-water filling materials were developed based on the SAC green materials. CO2 emissions were reduced by 58% in SAC preparation by using ISW compared with conventional SAC preparation. Full use of the ISW to produce high-performance SAC green materials is a sustainable option and a possible path to decrease CO2 emissions in the SAC industry.