Potential of spodumene tailings as a raw material in porcelain stoneware tile composition

Abstract

Given the increasing accumulation of spodumene tailings resulting from lithium extraction, there is a growing need to identify suitable applications for these residues. The characterization tests conducted on the spodumene tailings showed an adequate amount of silica and alumina for their use as raw materials for ceramics. Therefore, in this study, spodumene tailings composed of quartz–feldspar sand (QFS) were used to produce ceramic tiles, with the porcelain stoneware formulation serving as a comparative reference. The material is incorporated as a mineral additive in the reference porcelain stoneware composition to determine the optimal dosage while staying within a typical porcelain stoneware composition. To check if the produced tiles could be classified as porcelain according to standard definitions, different sintering temperatures and dwell times were tested, aiming to identify the processing conditions under which the ceramic bodies meet the essential requirements. To evaluate the tiles’ properties, a range of characterization tests were performed, including water absorption, apparent density, open porosity, modulus of rupture, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and dilatometry. The results indicate that increasing the sintering temperature and dwell time directly reduces the open porosity and water absorption of the tiles, even in samples containing mine tailings. The proportion of tailings in the tile composition was not directly correlated with the tested properties of the tiles, as compared with the reference composition without tailings. However, the addition of tailings improved some properties like flexural strength and thermal stability at an optimum dosage of 25–35 wt%. These improvements demonstrate the potential of spodumene tailings as a viable raw material for ceramic tile production when benchmarked against porcelain stoneware and other ceramic standards. This improvement was attributed to the optimized alumina-to-silica ratio and the higher concentration of alkaline oxides compared with the other compositions.