Recycling fly ash and red mud to manufacture self-foaming ceramic foams

Abstract

Manufacturing ceramic foams derived from solid waste can not only alleviate hazards to the environment, but also obtain high value-added products. The self-foaming ceramic foams were prepared by recycling fly ash (FA) and red mud (RM) as raw materials. The pore structure, physical and mechanical properties of the sintered foams subjected to different sintering schedules were investigated. The results showed that the ceramic foams performed a self-foaming procedure in the course of sintering, derived from the combustion of the organic materials and/or the decomposition of the carbonates in the studied FA and RM. The sample sintered at 675 °C for 60 min exhibited promising properties, including a bulk density of 331 kg∙m-3, a porosity of 83.8 %, a water absorption of 2.91 % and a compressive strength of 1.96 MPa, which has good potential application in the fields of insulation, gardening and lightweight constructions.