Preparation and characterization of red mud based porous materials

Abstract

China was a large country in bauxite mining and refining. One ton of alumina was produced, accompanied by 0.5 ~ 2 tons of red mud [1]. Therefore, the accumulation and pollution of red mud had been a difficult problem to be solved by enterprises and local governments. In this paper, red mud based porous materials were prepared with Bayer red mud, perlite, silicon carbide (as foaming agent) and glass powder (as flux). The effects of sintering process and iron oxide on thermal conductivity, bulk density, porosity and compressive strength of red mud based porous materials were studied by TG-DSC, XRD, SEM and XEDS. The results show that red mud based porous materials with uniform pore distribution could be obtained when the amount of red mud was 60%, perlite was 37%, SiC was 1%, glass powder was 2%, sintering temperature was 1150 °C and holding time was 120 min. The true porosity of the red mud based porous material was 70%, and the average pore diameter was 216.84 μ m. The thermal conductivity was 0.26w / (m • K) and the compressive strength was 2.31MPa.