Progradex’s, Toby Day, addressing the conference with a keynote speech on new technologies in drill hole sampling.
Day’s presentation was well received by the 200 delegates that attended Sampling 2012. The Progradex Sampling System formed the cornerstone of the speech with in-depth pictorial explaination on how the new revolutionary sampling system works but there was a great deal more to this presentation. It looked at the process of RC drilling and the various sub-processes that are critical to a successful RC sampling outcome for both grade control and exploration applications.
Starting with a detailed look into the selection process for RC hammers, Day went on to explain how each component in the RC drill string has great bearing on the ultimate representivity of a RC bag sample. He discussed “face sampling” RC hammers & bit/shroud selection, drill rod tool joint design and its effect on compressor efficiency & sample condition, the importance of a blowdown valve to maintain dry samples & minimise contamination, the roll of deflector boxes & the effect of poor design and, of course, the Progradex Sampler. But the address also covered the safety aspects associated with these selection decisions and how internal and external dust can now be completely controlled in any RC drilling application to the point where we are now able to seriously consider RC drilling for underground applications, a step forward that Day himself is passionate about bringing to fruition.
Delegates were then treated to a case study presentation on the sample results from a Progradex Sampler operating at the massive Pueblo Viejo Gold Mine in the Dominican Republic by Matt Almond of Barrick Gold Corporation. Almond’s presentation supported a technical paper, written by Mick Goers (Geology Chief – Pueblo Viejo) and published for the first time at the conference, detailing side-by-side HARD Plot duplicate repeatability comparisons between results from the Progradex Sampler, UDR Sampler (a previous T. Day designed sampling system) and a Cyclone/Riffle Splitter Sampler.
Iain Ross – Chief Advisor, Cave Engineering (Rio Tinto), Amir Mokaramian – Dept Petroleum Engineering (Curtain University), Matt Almond – Senior Production Geologist (Barrick Gold Corp, Pueblo Viejo Gold Mine) and Ben Ziegelaar (Session Chair) – Technical Director (Yankuang Resources)
The paper concluded that the highly representative and compliant results seen from the Progradex Sampler were considered the superior of the three systems because of the Progradex system’s ability to present 100% collection efficiency for sampling (coarse and fine dust sampled) and that this will ultimately be confirmed with further testwork following mill reconciliations.
The other significant point that this study highlighted is that duplicate repeatability tests for sampling QA/QC is not, as previously thought, necessarily providing the complete picture when it comes to sample representivity and more work needs to be done in this area.
The Barrick paper is available for distribution by contacting Progradex on firstname.lastname@example.org.