Milling parameters and solid waste characterisation to use as supplementary cementitious materials

Parâmetros de moagem e caracterização de resíduos sólidos para aplicação como materiais cimentícios suplementares

Abstract

Despitethe increasing number of publications on residual raw materials as supplementary cementitious materials (SCM), the milling beneficiation process and its parameters have been underexplored and presented. In this context, this study aims to evaluate the milling parameters for marble, clay tile, clay brick, and phosphogypsum waste processing for recycling as SCM. The raw materials were benefitted by grinding, sieving, and milling in a planetary ball mill, varying the time and rotation speed parameters. The waste was characterised by helium gas pycnometry, DSC, BET specific surface area, XRF, TGA, and XRD/Rietveld. Waste materials in which the mineral composition of phases was formed at higher temperatures were associated with higher demands for specific milling energy and lower grindability indexes. Marble waste (MW) has a mineral composition similar to commercial limestone and phosphogypsum (PG) can be an alternative to natural gypsum in cementitious materials. Clay brick waste (CBW) and clay tile waste (CTW) have the potential to be used as SCM to replace calcined natural clays, although CTW requires higher energy during milling processes.

Keywords:
Milling; Marble waste; Clay tile waste; Clay brick waste; Phosphogypsum; Supplementary cementitious materials