Preparation and properties of low-temperature self-expanding foamed ceramics utilizing lepidolite mica ore and ceramic tile polishing waste

Abstract

Foamed ceramics were prepared at temperatures of 1175 °C, 1200 °C, 1225 °C, 1250 °C, and 1275 °C using lepidolite mica ore, ceramic tile polishing waste, and fly ash as raw materials, with borax as a fluxing agent. The main source of the foaming material was determined as SiC, followed by anorthite and iron oxide, based on the X-ray diffraction (XRD) patterns of the raw materials and the thermal analysis (TG-DTA) results of the raw materials and SiC. The effects of the raw material ratio and borax content on the samples' phase composition, compressive strength, microstructure, thermal insulation, and corrosion resistance were systematically studied. The results show that the pore structure of the foamed ceramics sintered at 1225 °C with 25 wt% lithium mica ore, 50 wt% ceramic tile polishing waste and 25 wt% fly ash were uniform. However, based on the above ingredients, 18 wt% borax was added to reduce the firing temperature by 300 °C. After firing at 925 °C and holding for 30 min, the samples' average pore size, bulk density, compressive strength, and porosity were 0.58 mm, 0.66 g/cm3, 10.256 MPa, and 83.1 wt%, respectively. It exhibits good thermal insulation and corrosion resistance, and its performance meets the requirements for building insulation materials, making it an energy-saving and environmentally friendly building material.