Firing behavior of argillites from northern Tunisia as raw materials for ceramic applications

Abstract

This study reports the firing properties of clayey materials from northern Tunisia to evaluate their possible use as raw material in ceramic. Physical, chemical, and mineralogical characterization and thermal behavior were carried out by inductively coupled plasma atomic emission, X‐ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, particle size distribution, and Atterberg limits tests. Firing properties were evaluated by color, firing shrinkage, water absorption, bulk density, apparent porosity, and flexural strength. Studied clayey materials are made up mainly by kaolinite and illite and are rich in iron. The main transformations after thermal analysis were identified from 500°C to 1000°C subsequent to the dehydroxylation of clay minerals, calcite decomposition, and the recrystallization process. Fired samples up to 1100°C showed better physical and mechanical properties related with a great densification resulting in a significant increase in linear shrinkage, bulk density, and flexural strength and a decrease in apparent porosity and water absorption up to 1100°C. This behavior is due to a crystalline and liquid phases formed at low firing temperature associated with a high content of fluxing agents. The fired ceramic materials exhibited low water absorption up to 2.26% and high flexural strength up to 32.6 MPa, which makes their potential use for some earthenware and stoneware products.

Impact of Nanoparticle Additions on Life Cycle Assessment (LCA) of Ceramic Tiles Production

“…Only the TF clay test tiles with CuFe 2 O 4 and Fe 3 O 4 nanoparticle additions showed an increase in flexural strength up to 9% and 16%, respectively, at 1% ( w / w ) compared with the 0% ( w / w ) mixture. The low water absorption (2.8% and 2.5%) at 1% ( w / w ) magnetite nanoparticles indicate a higher density of the test tile and, consequently, a higher flexural strength (1787 N) promoted by the formation of a crystalline and liquid-phase developed at low-temperature associated with the iron oxide content [ 73 , 74 , 75 ]. Test tiles with the addition of Ag 2 O and SiO 2 nanoparticles decreased the flexural strength by 13–16% and 1–5%, respectively, at 1% and 5% ( w / w ), compared at 0% mixture.…”

Reducing Water Absorption and Improving Flexural Strength of Aluminosilicate Ceramics by MnO2 Doping

“…Figure 6 shows the FTIR spectra of the six sintered ceramic samples. The peaks appearing at 779 and 798 cm −1 are from the quartz phase [ 36 ]. And the absorption band at 1033 and 1010 cm −1 arise from the vibrations of Si-O-Si and Si-O-Al, respectively [ 14 ].…”