INVESTIGATING THE PERFORMANCE OF DIFFERENT EXPLOSIVES ON SELECTED ROCKS IN SOME QUARRIES IN AKOKO-EDO, SOUTH-WESTERN NIGERIA

Abstract

The study investigated the performance of different explosives on some selected rock types. To achieve the set objectives, granite samples were collected from Julius Dinga Ltd Iyuku, calcitic-marble samples from Geoworks Ltd Igarra and Dolomitic-marble samples from Freedom quarry Ikpeshi all in Akoko-Edo, South-Western Nigeria. These samples were subjected for uniaxial compressive strength test and mineralogical analysis. The result of uniaxial compressive strength reveals that granite has 133.55MPa, calcitic-marble has 78.91MPa and Dolomitic-marble has 71.17MPa. From mineralogical analysis, granite has 44% quartz, 49% feldspar, 5% hornblende and 3% muscovite, calcitic-marble has 95% calcite and 5% dolomite and dolomitic-marble has 55% calcite, 45% dolomite respectively. Field measurements were also conducted using Scanline method and clinometers for determining discontinuity spacing and dip and dip direction of discontinuities respectively. In general there are two subvertical joints with the following dips and dip directions, for Julius Dinga Nigeria Iyuku granite are 85°/ 344° and 85° /317°, for Geoworks Igarra calcitic-marble are 85° /041° and 84° /056° and for Freedom Ikpeshi Dolomitic-marble are 86° /321°and 82° /041° respectively. The in situ block size distribution was also estimated using both empirical and AutoCAD©. Joint spacing, block volume and volumetric joint count methods were used for empirical block size estimation. Four different types of explosives that are Special Gelatine, Emulsion, Slurry and ANFO were used to carry out four blasting operations each on three types of rock selected. Out of the four explosives used, Special Gelatine is the most efficient explosive for blasting of granite with efficiency of 64% and over efficient for other types of rock that is it turn them to powder, Emulsion is found the most efficient explosive for blasting of calcitic marble with efficiency of 62%, Slurry is the most efficient explosive for blasting of Dolomitic marble with efficiency of 64% and ANFO is found inefficient for all selected rocks except that it should be used as low explosive combined with other higher explosives.