Studio di miscele refrattarie per spruzzatura a caldo mediante misura del modulo di rottura

Abstract

The modulus of rupture of four different refractory mixtures for coke ovens repair by hot gunning was determined. The materials were characterized by chemical, granulometric and phase analyses, optical microscopy and apparent density measurements. MOR values were determined by three points flexural test using prismatic specimens obtained by ramming of aqueous mixtures of the monolithic materials and firing. These values were related with the aggregate and bonding phase characteristics of the refractory materials and with the fired bar microstructures. MOR values were also considered to analyze the cohesion of each fired material and correlated with hot adhesion of mixtures on silica bricks. Results show that even though the refractory behavior at working temperatures cannot be directly derived from the modulus of rupture at room temperature (MOR), this value may give some useful indication to make a first selection of hot gunning refractory mixtures.