Influence of petrographic characteristics of granites on the industrial process of blocks sawing

Author(s)

Rogério Pinto Ribeiro

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2005-12-19

Examining board members

Antenor Braga Paraguassu; Antonio Carlos Artur; Ely Borges Frazao; Reinaldo Lorandi; Jose Eduardo Rodrigues

• Advisor: Antenor Braga Paraguassu

Abstract

The sawing of granites blocks using multiblade gangsaws is one of the most complex operations in the stone processing industry. The slab surface quality (roughness) obtained after the sawing process determines the time and the inputs required in subsequent polishing operations and thus has a direct implication on the final product cost. Although Brazil is one of the largest world producers of ornamental granites (four million 'M POT.2'/month of slabs), it is surprising to note that there are very little or no scientific literature works available that address major aspects of the intrinsic properties of granites and their role during the sawing process. The present research has the major objective of correlating petrographic parameters with physical and mechanical characteristics of granites with a major emphasis on the role played by mineralogy and textural/structural anisotropy focusing mainly on how to obtain the best orientation during this industrial stage. The samples used are the most widely used granite of high commercial value in Brazil. The sawing process was monitored and subsequent direct measures of the roughness of the sawed surfaces carried out using an equipment specially built for this purpose. The results obtained show that textural (granulation, arrangement, imbrication, degree of microcracking) and alteration aspects of the minerals are responsible for the observed differences in slab roughness and processing speed (AU)