COSTA, J. B. B.; http://lattes.cnpq.br/3238496416676717; COSTA, João Bosco Burgos.
Résumé:
Traditionally the characterization of ornamental rocks is limited to the aspects related to the
use of final products. That type of characterization is made for commercial purposes.
However, there i t is possible to correlate those rock technological characteristics with quarry
operations, especially regarding the utilization o f diamond wire sawing. The present research
addresses the correlations among rock properties and performance of diamond wire sawing,
during the extinction o f dimension stones. The study is based on a survey and analysis of
operational data and technologic tests performed in a group o f silicate rocks, from quarries
located in Paraiba and Rio Grande do Norte states. The operational parameter used in the
correlations is the yield, that is, number of square meters of rock cut per linear meter of
diamond wire, up to the complete wear o f the diamond wire. The technological characteristics
of the analyzed rocks are the following: 1) Petrographic analysis, regarding the percentage of
quartz and the weighted average o f the absolute hardness. 2) Uniaxial compressive strength,
obtained indirectly using a point load test (PLT) equipment. 3) Flexure strength, based on
standard procedures for dimension stones. 4) Amsler abrasion testing, also based on standard
procedures for dimension stones. 5) Surface hardness, obtained using a Schmidt hammer
device. The yield of diamond wire cutting is outlined based on the magnitude of the rock
technological characteristics. For building a predictive model the rock properties that showed
the best correlations were selected. The independent variables used were absolute hardness
(Da) and Amsler abrasion index (Dam), that showed linear correlation coefficients equal to -
0,80 and 0,73, respectively. The dependent variable is the diamond wire yield (Rf). It has been
observed that a model with multiple correlation showed a very good correlation coefficient,
namely R = 0,9489. The model proposed i n the present research may be used for predicting
the yield o f sawing operations using diamond wire. The proposed methodology, implemented
by means o f statistical studies, constitutes a useful tool for avoiding unnecessary expenditures
in the development of new quarries as well as for quarries in operation. The proposed
approach is considered a practical and low cost technique.
