Mechanical properties of sintered ceramsite from iron ore tailings affected by two-region structure

As industrial waste, iron ore tailings (IOTs) can be mixed with bentonite and bauxite and subsequently sintered into ceramsite. Under sintering at 1120 degrees C, ceramsite with 60- wt% IOTs, 30- wt% bentonite, and 10- wt% bauxite showed an optimal cylinder compressive strength of 10.53 MPa, bulk density of 917.84 kg m(-3), 1-h water absorption of 9.9%, and porosity of 14.33%. Due to the different amounts of IOTs added to the ceramsite, a two-region structure is formed, which includes a red peripheral region that is rich in crystallisation and a black central region characterized by a vitreous structure. The number of vitreous components present in the structure was directly proportional to the cylinder compressive strength. Moreover, the increase in Fe2+ derived from IOTs played an important role in the formation of vitreous components. Ceramsite exhibiting a high strength can be used to prepare lightweight partition boards, which exhibit a light weight, durability, high strength, shock resistance, and good heat preservation as well as moisturizing properties. (C) 2019 Elsevier Ltd. All rights reserved.