Development of heavyweight aggregate via in-situ growth of high density ceramics using red mud

Abstract

The recycling and large stockpile of red mud, lead to a series of social and environmental concerns as bulk utilization of red mud is the demand of the modern age. Hence we develop a process for the bulk utilization of red mud into heavyweight aggregate. The development of heavyweight aggregate (HWA) using red mud, barium sulfate, and activated charcoal powder as a reducing agent has been used in the present investigation. We have observed an in-situ growth of different high-density ceramics such as barium iron oxide, barium titanate (BaTiO3), and barium iron titanium silicate (Bafertisite), etc., which may be responsible for the high strength and density. HWA and raw material have been characterized using different characterization techniques such as XRD, FE-SEM, TGA, and FT-IR, etc. A thermogravimetric analysis confirmed the removal of a different low molecular component during sintering from 500 to 1000℃. HWA is also characterized by mechanical properties such as water absorption, density, crushing, impact, and abrasion value. Whereas, we achieved maximum density upto 4.1 g/cm3 at an elevated temperature of 1350 ℃. These aggregates possessed lower water absorption, crushing, impact, and abrasion value upto 0.9, 18, 11.5, and 18.9 percent, respectively, compared to natural aggregates. The developed aggregate also fulfills the requirement of TS EN 206–1 (2002) and ASTM C637.