Recycling of waste sand from investment casting in ceramic wall tile production

Abstract

In this study, wall tile bodies were produced by addition of different types of investment casting waste sand (ICWS) instead of clay and kaolin. Recycling has gained great importance today in order to protect the environment and contribute to the economy. There are limited studies in the literature on the recycling of investment casting waste sand, and this study aims to reduce raw material consumption and provide economical wall tile production by utilizing the valuable components such as zircon in the waste sand that emerge as waste material. Slip viscosity and slip density, density, water absorption, dry and firing shrinkage, dry and firing strength values of wall tile bodies were investigated. Color measurements, XRD and SEM analyses of those bodies were also conducted. Wall tile bodies incorporating of ICWS had generally higher density, firing shrinkage, dry and firing strength, but lower water absorption and dry shrinkage values than those of the reference wall tile. All wall tile slurries had similar densities but slip viscosities of wall tiles incorporating of ICWS generally lower than that of reference due to separation of particles. WX1 had nearly same whiteness value (L*) with reference wall tile, but higher in WX2, WX3, WY and WZ. All of the bodies had quartz, primary mullite and anorthite as main phases, also zircon phase was determined in bodies incorporating ICWS.