APPROXIMATION OF SURFACE AREA OF FINES IN BLAST INDUCED FRAGMENTATION

摘要

The surface area of fragmentation, especially in the finer size fractions, is a useful property torncharacterise the mechanisms of rock breakage. In the past, researchers have made assumptions withrnregard to the shape of fragments in order to estimate surface area, such as that all fragments are thernsame shape or all fragments are spheres. Often these assumptions were developed with inappropriaternmeasures and returned considerable variability and error for the calculation of surface area.rnThis paper reports a model to estimate fragmentation surface area from sieve sized raw data and arndensity measurement, with experimental validation down to a size fraction of –45 + 38 μm in a rangernof rock types.rnAfter characterisation of particle shape, a range of fragment shapes was found to be in each sizernfraction. Nevertheless, in the √2 sieve series the average fragment mass, volume and the size fractionrnstandard deviations could be predicted reasonably accurately. Ellipsoid geometry was used torndescribe particle shape. Using these parameters and the number of fragments (also predicted) inrneach sieve size the individual surface area of each fragment was simulated.