Whole solid waste inorganic lightweight material: Preparation and effects of various parameters on its properties

Abstract

Flammable conventional organic foam materials imply fire hazards to constructions and buildings. Given that the accumulated alkaline solid wastes, such as red mud (RM) and carbide slag (CS), seriously damage the ecology, their safe utilization in developing nonflammable inorganic foam building materials is very lucrative. This study produced whole solid waste inorganic foam materials through chemical foaming, with aluminum powder used as a foaming agent. This preparation process was optimized by studying the effects of aluminum powder content, water-binder ratio, and stirring water temperature(Water temperature used in the experiment) on the absolute dry density, compressive strength, porosity, pore morphology, and pore size distribution of the specimens. The increase in aluminum powder content and water-binder ratio lead to a decrease in density and compressive strength, while the rising stirring water temperature resulted in opposite trends in porosity and compressive strength. The optimal experimental parameters (aluminum powder content of 1 %, water-binder ratio of 0.7 wt%, and stirring water temperature of 40℃) provide the foam specimen’s porosity of 33.2 %, compressive strength of 0.41 MPa after 28 days, and a dry density below 0.5 g/cm3.