Utilization of Estremoz marbles sawing sludge in ceramic industry – Preliminary Approach

Abstract

Portugal is in forefront of world marble production, the marble quarries and processing industries in Estremoz region has an important role in economic life. The amount of waste produced by this activity is massive and cause several problems.

The aim of this study is to investigate the suitability and the effect of Estremoz marble sawing sludge in mixtures with clay to ceramic industry. Another main concern is the manufacture of environmental friend ceramics.

Plasticity behavior of clay mixtures with 2.5, 5, 10, 15 and 20wt% of marble powder were evaluated. The incorporation of waste reduces the liquid limit and plastic index of pastes.

Clay bodies were molded by uniaxial pressure and fired at maximum temperature of 950ºC. The results reveal that the addiction of marble powder increases the water absorption, apparent porosity while the bulk density decreases. Due to their influence in the melted phase an improvement in mechanical strength characteristics was registered, namely in rupture modulus.

This preliminary study shows that the use such mixtures are promising in term of ceramics technological properties.

Keywords: Estremoz marbles, clay, reuse, ceramics.