Resistência ao ataque químico de granitos ornamentais do stock Serra do Barriga - Sobral/CE

Abstract

Here is presented results from resistance to chemical attack provided by four types of granitic stock Serra do Barriga, through the loss of luster, color variations, minerals alterations, beyond the influence of petrography. Chemical reagents were used simulating the effects caused by cleaning products or organic substances on the granites. Although we have differences in grain and the mineralogical proportions, the granites responds very similarly form to the reagents, with subtle color and mineralogical alterations. However, the white granites are more resistant due to the higher amount of quartz and the roses have higher loss of luster and corrosion minerals due to the higher proportion of feldspars and mafic minerals, making the alteration effects more apparent. The HCl and C6H8O7 show higher power alteration over the granite (higher corrosion and loss of luster), while KOH cause dissolution and increased porosity. The NH4Cl and NaOCl cause subtle mineral alterations without perceptible chromatic variation. Although granites show relatively resistant to chemicals, it is recommended to prevent prolonged exposure to substances containing HCl and C6H8O7 acids, in addition to the KOH, demonstrated aggressive.