Spodumene tailings for porcelain and structural materials: Effect of temperature (1050–1200 °C) on the sintering and properties

Abstract

The use of industrial by-products as substitute to conventional natural resources in ceramic production is of interest from an environment preservation and solid wastes management. This paper deals with the recycling of tailings from spodumene concentration during lithium production (Quartz Feldspar Sand; QFS), for the production of porcelain and structural materials. The QFS obtained from spodumene processing consisted mainly of quartz, albite, microcline with traces of muscovite. Mixtures of QFS and standard porcelain ingredients were sintered at 1050-1200 °C at 50 °C intervals and their properties were compared with a conventional porcelain composition prepared under the same conditions. Phase composition was assessed by XRD analysis using Rietveld refinement. Tests such as water absorption, apparent density, sintering shrinkage, compressive and flexural strength were used for physical comparison. The results showed that higher densification was achieved at 1200 °C, with a drastic reduction of water absorption below 1%. A compressive strength of 40 MPa was obtained at 1050 °C in the composition made of 50 wt% QFS and 50 wt% kaolin, increasing to 85 MPa at 1100°C. The strength increase was attributed to better glassy phase formation and mullite growth. The QFS was found to contain no hazardous elements and showed promising sintering results, indicating its high suitability to substitute conventional resources in the production of ceramic materials.

Incorporation of sulphidic mining waste material in ceramic roof tiles and blocks

“…In this case study, the consumption of primary raw materials (clay) was reduced and the energy consumption during firing decreased due to the lower lime content of the mining waste. Moreover, mining waste (spodumene, LiAlSi 2 O 6 , ore tailings) integration in low-temperature ceramic bricks have shown compliance with product specifications (Lemougna et al, 2019a), promising sintering results as well as compliance with environmental regulations (Lemougna et al, 2019b). Mining tailings from Ag-Au exploitation have been used as feldspar substitutes to manufacture ceramic bricks, giving similar or better technical properties to that of a conventional brick (Salinas-Rodríguez et al, 2017).…”

“…The use of mining waste materials (spodumene, LiAlSi 2 O 6 , ore tailings) was also studied in highperformance ceramics, also called technical ceramics, and they have shown to achieve high mechanical performances and compliance with product specifications (Lemougna et al, 2020). Moreover, the use of spodumene tailings in porcelain ware, showed promising sintering results always comparable to the reference (Lemougna et al, 2019b).…”

Mullite-Based Ceramics from Mining Waste: A Review

“…One of the main routes of lithium extraction is acid roasting with H 2 SO 4 of the mineral spodumene (LiAlSi 2 O 6 ), which contains approximately 8% of Li 2 O [109][110][111]. Lemougna et al [112] studied the use of quartz feldspar sand (QFS) residues originating during the chemical production of lithium from spodumene as a raw material for the manufacture of porcelain and structural materials. Table 11 shows the chemical composition of this waste together with the processing parameters and technological properties of the final ceramic materials.…”

Sintering Behavior and Technological Properties of Low-Temperature Porcelain Tiles Prepared Using a Lithium Ore and Silica Crucible Waste

“…The calcined kaolin used to be exposed to a high temperature of 1200 • C, and, in this process, various forms of H 2 O were removed. Different from the high loss on ignition (7-14%) of industrial clay [1][2][3]19], calcined kaolin will not produce gas in the sintering process, which is conducive to improving the compactness of ceramic. The phases of the calcined kaolin consist of quartz, mullite, cristobalite, and a vitreous phase (Figure 1c).…”

“…The phase present should be secondary mullite (3Al 2 O 3 •2SiO 2 ), since there is no clay present in the raw materials [40][41][42]. This secondary mullite is likely to be acicular crystals and will improve the mechanical properties of the ceramics [19,43]. On the other hand, the mullite content is mostly lower than 26% when the firing temperature exceeds 1100 • C. This finding is because the stability of mullite decreases at increasing temperatures for the SiO 2 -Al 2 O 3 -Na 2 O and SiO 2 -Al 2 O3-K 2 O systems (Figure 3a,b), and a large amount of Al 2 O 3 and SiO 2 enters the vitreous phase at these temperatures, rather than only the secondary mullite.…”