Blasthole Sampler-Analyzer - a new tool for grade control
IMA Blasthole Sampler-Analyzers, called the OREalyzer, collect samples and dense drill cuttings data from production holes. This massive real-time data can be used be used to make accurate block models of the blast fields. Relatively small block sizes like 2m*2m*2m can be used at ore-waste contact to avoid waste rock dilution. Improvement compared to conventional grade control can be easily demonstrated (see figure). Economic improvements, like +10% in mill head grade, is significant and can be calculated.
Today mines have no practical means to estimate ore losses in mining. Accurate 3D model of the bench can be used to measure ore losses. Not only the economic improvements can be reached, but sending sulfidic ore or waste rock to inert waste area can be avoided. Mine planning tools can be used to make economic calculation (see figure) and chemical analysis shows when waste can be send to inert waste area.
IMA Blasthole Sampler-Analyzers are producing high quality, representative, drill cuttings samples. Both the sampling system and the on-line (XRF) analyzer are now integrated into the drill rig (see Atlas Copco D65 SmartRoc and PDSA OREalyzer). Atlas D65 rig combines Measure While Drilling (MWD) and analysis data into the same file of each drilled meter. MWD data is important to estimate rock quality in blast benches.
The other model, Blasthole Sampler-Analyzer (BSA) is in field test phase on big rotary drill rigs.
The BSA model collects primary samples from the blasthole collar and moves them into the analyzer unit, which then analyzes samples with production speed.
Optionally a secondary sampling splitter and bagging device, the Rotary AutoSampler (RAS), Bag & Tag unit can be integrated with the BSA to collect physical samples to the laboratory.
Why IMA Sampler-Analyzers are needed?
Conventional blasthole drill cuttings sampling technology often leads in non-representative ore samples. The reason is that it is impossible to get
fully representative samples from cuttings cones formed on the hole collar.
IMA Sampler-Analyzers collect continuously ideal frequent samples (several for every meter). Frequent sampling and instant analysis as shown in figure below is superior to any other method available.