Raw materials, waste recycling and sustainability of ceramics

Contact persons:  Michele Dondi, Chiara Zanelli
People involved: Sonia Conte, Chiara Molinari, Roberto Soldati, Guia Guarini

The ceramic industry is facing the challenges of sustainability, adopting processes and technologies with a low environmental impact. In addition, it is trying to improve its own resource efficiency, since ceramic products for construction, domestic and industrial uses are obtained making a wide use of natural raw materials. Looking at the transition towards a circular economy, it is fundamental to strengthen the capacity to recycle urban and industrial wastes by a larger use of secondary raw materials.

In this field, CNR-ISTEC is involved in prospecting, characterizing and developing new deposits and uses of raw materials for ceramics, and also in modelling their properties and technological behavior. Special attention is paid to recycling of industrial wastes and byproducts in ceramic manufacturing, where CNR-ISTEC has a plurennial experience including: laboratory testing; assistance in industrial trials; consultancy and product and process problem-solving; data-base on the use of civil and industrial residues in ceramics.

Equipment and processes

Raw material classification. Compositional and technological characterization of clay materials (kaolins, ball clays, common clays and shales, pyrophyllite, bentonite, etc.), fluxes (feldspars, feldspathoids, feldspathic rocks), fillers (quartz and quartzous rocks), pore-forming agents and sintering promoters (calcite, dolomite and carbonatic rocks; talc, wollastonite, lithium minerals, etc.), opacifiers (zircon, corundum, etc.). Quantitative chemical (ICP-OES) and mineralogical (XRD, Rietveld-RIR) analyses; particle size distribution (Sedigraph); specific surface area (BET); plasticity (Atterberg, Methylene Blue index, Pfefferkorn); drying behaviour (Bigot curve, retractometer); thermal behaviour (TGA, DTA, DSC); fusibility (hot stage microscope). Laboratory simulation of the manufacturing processes of ceramic tiles, refractories, clay bricks and roof tiles, lightweight aggregates, sanitaryware, with measurement of technological properties of semi-finished and finished products.

Main collaborations

Department of Earth Sciences, Federico II Università di Napoli;
Geology Department, Univesidad Nacional del Sur, Argentina;
Instituto de Technology Ceramics, Castellon de la Plana, Spain.