Preparation and Process Optimization of All-Solid Waste-Based Porous Ceramics

Abstract

The fine mud (LTM) produced during the flotation process of lithium mica tailings is a recyclable solid waste. This paper used LTM as raw material, a small amount of silicon carbide and calcium carbonate composite foaming agent was added, and solid waste-based porous ceramics were prepared by the sintering method. The effects of sintering temperature (1120-1200 °C), holding time (20-120 min), silicon carbide (0.6-1.4 wt.%), and calcium carbonate (0-4 wt.%) addition on the compressive strength, porosity, density, water absorption and thermal conductivity of porous ceramics were studied. By comparison, the optimal process parameters were determined to be LTM-SiC-CaCO3=96 %-1 %-3 %, sintering temperature of 1160 °C, and holding time of 60min. The porous ceramic material obtained under this process parameter exhibits the best comprehensive performance: compressive strength (5.474 MPa), porosity (70.152 wt.%), density (0.557 g/cm3), water absorption (11.236 wt.%), and thermal conductivity (0.077 W/m·K). In addition, the static adsorption test of LEM-based porous ceramics in water showed that it has a good N and P adsorption effect in simulated water bodies for eutrophication so that it can be developed as porous ceramics for water purification in the future.

Keywords: lepidolite, porous ceramics, Performance, solid waste