Chemical, phasic and calorimetric evaluation of a pozzolanic material obtained by electric arc-assisted aluminothermy using cupola slag

Abstract

The purpose of this study was to evaluate the chemical, phasic and calorimetric evaluation of a pozzolanic material obtained by electric arc-assisted aluminothermy using cupola slag to provide criteria on its pozzolanic nature. Chemical characterization of cupola slag and synthesized pozzolanic material (MPS) was performed by using analytical methods such as volatilization gravimetry, complex formation volumetry, UV-VIS spectrophotometry, atomic absorption spectrometry, and phase characterization using semi quantitative analysis by XRD. The pozzolanic character of cupola slag and MPS was evaluated by means of alkaline solubility tests and isothermal calorimetry in Ca(OH)2-Puzolana and Portland Cement (CP)-Pozzolan paste systems. Cupola slag does not contain more than 70% of SiO2, Al2O3 and Fe2O3 as indicated in NC TS 528: 2007 for its use as pozzolan and has 60 % amorphism, while the MPS complies with the provisions of the standard and presents a 30 % amorphism. The highest values of the Si and Al contents in the cupola slag respect to MPS and the zeolite studied are associated with the predominance of a non-periodic distribution of these chemical elements in the amorphous domains. Higher pozzolanic reactivity of the MPS respect to cupola slag obtained by isothermal Ca(OH)2-Pozolana and CP-Pozzolan calorimetry is attributed to a combination of amorphous character with the increasing of reactive phases result from chemical and phase modifications by using aluminothermy in an electric arc furnace.

Keywords

• escoria de cubilote
• aluminotermia
• material puzolánico sintetizado
• carácter puzolánico.