This was my first experience at the Annual SME conference and exhibition. For someone accustomed to the smaller, more specific conferences offered by the AusIMM, the scale of SME took me by surprise.
The SME is designed to bring together all the disparate mining disciplines to encourage collaboration and integration across the full value chain. There were more than 100 technical sessions covering topics as diverse as safety, environment, ventilation, automation, flotation, exploration, geotech, comminution, mining and tailings. Unfortunately this meant that there were an average of 20 parallel sessions; one individual could only see a maximum of 5% of the technical information. Then there was the exhibition which contained more than 800 exhibitors, and although I personally attempted to absorb it all, I left feeling like I went to buffet and was not able to eat all the great food because there was not enough time and I was too full. But when I look back, I was able to connect with colleagues from around the world, learn a lot about other disciplines and discover innovations applicable to my field of comminution.
Colonel Mike Mullane opened the conference with a fantastic plenary that translated the lessons learned from what he called the ‘predictable surprise’ of the space shuttle Challenger disaster to teach us about team work and leadership. His main hypothesis was that a great team guards against ‘normalisation of deviance’ that occurs when job pressures and personal issues lead to short-cutting best practices until they become the norm. Courageous self-leaders set the bar high and incrementally challenge themselves because tenacity counts more than genius.
Ron Woods, Robert Dunne and David Dreisinger presented the Gaudin, Richards and Wadsworth Plenary Lectures to recognise their contribution to the fields of flotation, comminution and leaching. Rob Dunne’s lecture was of particular interest to me as he described his involvement in the design of the Cadia milling circuit. Cadia’s original design was 2 x 36ft SAG mills, but the design team was able to reduce CAPEX by 30% by going to a single 40ft SAG mill (the largest in the world at the time). This was the quintessential example of economies of scale, transforming a project to become profitable.
As part of the technical sessions Aidan Giblett presented Newmont’s learnings from operating milling circuits at Batu Hijau (SABC –B), Phoenix (full pre-crush SABC), Mt Charlotte (partial pre-crush SABC), Ahafo (SABC) and Boddington (HPGR – Ball). The key long-term control in all SAG and ball milling circuits required identification whether ore-types are SAG or ball mill limiting and altering the degree of secondary crushing, pebble crushing and pulp-lifter design to find a balance in the circuit. He also highlighted that secondary considerations for HPGR circuits are important for instance: increased float stability, reduced utilisation and the power efficiency can be eroded by ancillary equipment.
The Global Mining Standard Group (GMSG) presented the sampling and the bond efficiency guidelines which will be extremely useful to produce a standardised approach. Jan Miller presented an industrial-scale, high-speed tomography methodology that can process 60 x 3 kg buckets in an hour to a resolution of 160 µm. Michael Larson presented the effect of viscosity on IsaMilling and suggested using a Marsh Funnel for preliminary investigations with times greater than 38 seconds initiating greatly reduced efficiencies and recommended using P50 rather than P¬80 as an indicator of performance in viscosity limited mills.
I was fortunate to present two technical presentations at the conference: one investigating the use of the Energy Curves to compare laboratory scale testing against design and operation of AngloGold Ashanti’s Tropicana and Gramalote mines; and another as a replacement for Joe Pease in presenting the increasing orebody understanding to improve comminution efficiency.
Now, if I could just work out how to clone myself to get to all those other great lectures....