Effect of Textural Characteristics of Rock on Bit Wear

Abstract

The relationship between textural properties of selected Nigerian rocks and bit wear rate was investigated. These rock samples were tested in the laboratory for mineral composition, silica content and porosity. Also, average grain size and packing density were determined from photomicrograph of the samples using empirical equations proposed by researchers. Wear rates for each rock sample obtained on field were correlated with the textural properties to establish their relationships. The percentages of quartz and biotite are 42%, 30.56% for feldspar granite; 51.11%, 17.78% for biotite hornblende granite; and 57.14%, 26.98% for coarse biotite granite; respectively. The results show that all textural characteristics have high coefficient of correlation for all the samples. The highest wear rate was experienced on coarse biotite granite having mean packing density of 93.46%. This has revealed that wear of rock drill bit in quarries is related to textural rock properties and this will be necessary to have an overview of rock response to drilling.