Preparation and properties of porous ceramics from spodumene flotation tailings by low-temperature sintering
Jie Yang, Longhua Xu, Houqin Wu, Jiao Jin
Abstract
Porous ceramics were prepared with spodumene flotation talings (SFT), kaolin and low-melting point glass (LPG) powder, whose pores were formed by the chemical reaction of hydrogen peroxide (H2O2). LPG was used to reduce the sintering temperature of porous ceramics and kaolin was used to realize the adsorption to methylene blue (MB) of porous ceramics. The average flexural strength, compressive strength, apparent porosity, water absorption and maximum MB adsorption capacity were 5.60 MPa, 4.66 MPa, 52.27%, 44.32% and 0.7 mg/g, respectively. Moreover, the results of orthogonal experiments present that the sintering temperature and the dosage of H2O2 had great influence on the mechanical properties and apparent porosity of porous ceramics, respectively. The main reason for the improvement of mechanical properties of porous ceramics was that LPG gradually became soft with increasing the sintering temperature, which made the mineral particles adhere to each other closely. Kaolinite was not completely converted into metakaolin at 550 °C, which might be the main reason why porous ceramics had adsorption properties.