Open AccessSintering of sepiolite-rich by-products for the manufacture of lightweight aggregates: technological properties, thermal behavior and mineralogical changes
Author(s) -
José Manuel Moreno-Maroto,
Beatríz González-Corrochano,
Jacinto Alonso-Azcárate,
Carmen Martínez-García
Publication year - 2021
Publication title -
materiales de construcción
Language(s) - English
Resource type - Journals
eISSN - 1988-3226
pISSN - 0465-2746
DOI - 10.3989/mc.2021.05620
Subject(s) - materials science , sepiolite , sintering , diopside , composite material , quartz , raw material , mineralogy , chemistry , organic chemistry
A sepiolite mining by-product (SEP) has been studied as major component for lightweight aggregate (LWA) manufacture. Pellet bursting during firing was avoided by the addition of 2.5 wt% of thermoplastic waste (P) and 2.5 wt% P + 2.5 wt% carbon fiber residue (FC) in powder form. The mixtures were pelletized and then sintered at 1225º˚C for 4 minutes in a rotary kiln. Highly porous white LWAs with good mechanical strength were produced. A mineralogical study revealed the formation of amorphous phase ( > 50%) and minor proportions of enstatite, protoenstatite and diopside. Quartz was the only inherited mineral, appearing in the form of isolated phenocrysts within a general porphyritic texture. The result of this study suggests the promising use of sepiolite (whether or not in residue form) for the manufacture of high quality LWAs.