SAG '15 Conference Diary

By any standards the Semi-Autogenous and High Pressure Grinding Technology (SAG) conferences are very important events on the comminution calendar. Essentially operators' conferences, this was the 6th in the series, which was initiated in 1989, and has always been held in Vancouver, the previous one in 2011. This year's event was held over four days, from September 20-23 at the Pinnacle Hotel Vancouver Harbourfront, and was organised by the SAG Conference Foundation, a Canadian registered non-profit organisation.  

Vancouver Harbourfront

The conference attracted over 650 delegates engaged in the field of autogenous, semi-autogenous and HPGR grinding in the industrial and metalliferous mineral industries to an intensive 4-days of over 100 oral presentations, supplemented by poster displays, and for the first time in the series a trade exhibition. Roughly 64% of the attendance was from North America, 11% from Australia, 5% each from Chile and South Africa, the remaining 20% being thinly distributed over 26 countries.

This was my first attendance at a SAG conference, MEI being a media partner, so I knew little of what to expect, approaching the four days with anticipation of making new contacts amongst the huge audience. I used the exhibition area as a focus for networking and this is my diary of a great week in Vancouver.

Sunday September 20th

The conference was opened this morning by Bern Klein of the University of British Columbia, and Chairman of the Local Organising Committee. 

Bern Klein with local organising committee members Laurie Reemeyer,
Mike McClintock and Reem Roufail

 

With Technical Chairman Brendan Costello, of Fluor Canada,
one of my CSM students from the 1980s

As comminution is the most energy intensive operation in mineral processing, it was appropriate that the first five papers before the first coffee break dealt with energy in comminution and that the first of these was presented by Grant Ballantyne of the University of Queensland, and a member of the Coalition for Eco-Efficient Comminution (CEEC). The CEEC, still a relatively young organisation, now has a very high profile in the industry, and MEI is proud to have its involvement in Comminution '16 as an industry advocate.

Grant discussed the CEEC's energy curve program, which is growing rapidly, with over 1.3 billion tonnes of ore in the database already. This program shows each operation where it currently sits on the efficiency curve, similar to a cost curve. Not only does it show where an operation sits on the curve, it also shows the position relative to other mining operations, so that improvements in processing efficiency can be tracked using this tool. CEEC's program is offered free to the industry: operating data is analysed into the program; the individual detailed results are sent in confidence back to the participant, while the unidentified data is added to the collated global data.

CEEC is running workshops around the world to demonstrate the application of the CEEC energy curve. Details to sign up for the CEEC workshop prior to Comminution '16 are already on CEEC's web site and plans are in place for similar events in Perth, Brisbane, Santiago and Turkey over the next 12 months. Last month FLSmidth added its global strength to CEEC’s mission to accelerate the transfer of knowledge around more efficient and productive mineral processing strategies (MEIOnline).

CEEC Executive Officer Sarah Boucaut, board members Ivan Mullany and Zeljka Pokrajcic,
and Grant Ballantyne with FLSmidth Sr. Vice President-Executive Accounts Peter Flanagan

With Rob McIvor

In the same session as Grant's paper, Rob McIvor of Metcom Technologies, USA described and gave examples of grinding circuit efficiency measurements and systematic application for the improvement of grinding circuits. Rob will be presenting a keynote along these lines at Comminution '16 aimed squarely at operating metallurgists and company management, as well as a pre-conference workshop to assist plant metallurgical staff and equipment/material suppliers to manage and improve the processing performance of ball milling circuits with clarity and confidence (posting of 1st June).

Following Rob's presentation were a further 20 presentations, in sessions on energy, geometallurgy, pre-concentration, and testwork and ore characterisation for SAG and HPGR. A very full day from 8 am to 6.30 pm with short breaks for coffee and lunch. A nice feature, however, was the streaming of the presentations into the exhibition area, which facilitated dipping into and out of sessions.

Steve Morrell presented the first Geometallurgy paper, on global trends in ore hardness. Steve is founder of CITIC SMCC Process Technology Pty Ltd an Australian company which provides independent technical services to various mining projects, mainly in the area of comminution circuit design, technology and equipment selection, and optimisation of mineral processing plants. It operates as an independent consulting company, and is ultimately owned by Comminution '16 sponsor CITIC Heavy Industries, a market leader in China, with equipment operating successfully in China and around the world, including Asia, Europe, America, Africa and Australia.

Steve is 2nd left in the photo below, with Rajiv Kalra, managing director of CITIC Australia, Beny See Hoy, general manager North America and Mexico, and Dave Lumsden, global manager- crushing. On display was their stirred mill, three of which are currently being installed in Chile by Codelco.

Geometallurgy is becoming increasingly important in the minerals industry and Marcos Bueno of Australia's Ausenco stressed its importance in comminution testwork programmes, to characterise the ore in order to describe the variability of ore breakage properties. Geometallurgical approaches consider the mine sequencing and the characteristics of different ore types, thus minimising risk in comminution circuit design.

It's always good to meet husband and wife teams, and Henry and Susan Kurth, of Australian company Scantech, were no exception. Susan is Marketing Administrator and Henry Vice President-Sales for North America, and this afternoon he presented a paper on the Geoscan Elemental Analyser for optimising plant feed quality and process performance. Geoscan is used for multi-element analysis of conveyed bulk materials in real time, weighted tonnage results being used to monitor quality, divert increments (bulk sorting), ore blending and feed forward control to optimise downstream processes.

 

Monday September 21st

A nice feature of the conference is delegates' breakfast, a full hot and cold buffet served each morning from 6.30 in the conference area, where I have been able to catch up with a few familiar faces.

Malcolm Powel and Luis Tavares

Two of these were Profs. Malcolm Powell, of Australia's JKMRC, and Luis Marcelo Tavares of the University of Rio de Janeiro, Brazil, who presented papers on simulation this morning. Malcolm and Luis represent two of the six institutes comprising the Global Comminution Collaboration, which identifies comminution research needs and unifies the approach to working on these needs. The other four institutes are Sweden's Chalmers University, the University of Cape Town, Germany's Technische Universitat Braunschweig, and Turkey's Haceteppe University. At the recent AGM Luis stepped down as chairman, to be replaced for a one year stint by Prof. Arno Kwade of Braunschweig.

If yesterday was intensive then today certainly was, presentations commencing at 8am and finishing at 8.20pm, with two 20 minute coffee breaks and two one hour breaks for lunch and afternoon reception and buffet.

Nine posters were also displayed today in the exhibition area. Two of these were from Andritch Automation, who provide automation solutions, including controls, electrical and power engineering. The two poster presentations, the first entitled “Calculating SAG mill bearing pressure using thin film hydrodynamics” and the second “SAG-mill-optimization-using-model-predictive-control” emphasise the importance of modelling and advanced control in SAG mills. The long term vision is to enable the industry to more effectively use the equipment they have purchased through optimal circuit design and control. Andritch simulation tools help design or debottleneck mineral processing plants, and the company has donated its IDEAS simulator to mining Universities around the world, and at UBC the 40 license donation is being used at the undergraduate level to help students understand process unit operations when in steady state mode and also as a tool to introduce students to process control when in dynamic mode.

The Andritch team with UBC's Reem Roufail (3rd right) and Stefan Nadolski (2nd right)

The morning technical sessions contained presentations on Discrete Element Modelling, and Modelling and Simulation. After lunch there were sessions on Circuit Design and Mill Drives.

Metso has a high profile at most important conferences, and Victoria Herman, product manager for Metso's HRC High Pressure Grinding Rolls, gave a presentation this afternoon on the building of the world 's largest HPGR, the HRC3000, at the Morenci Metcalf Concentrator, part of the 63,500 tpd expansion at the Freeport-McMoran site. Victoria is photographed below with others in the Metso team.

Australian company Bradken is a leading supplier of high quality mill liner systems to suit AG/SAG, ball and rod mills, and in the evening session on Mill Liners, Product Technology Manager Craig Faulkner described a step change in liner design for the 32ft SAG mill at Kansanshi in Zambia.

Craig Faulkner, 3rd left, with other members of the Bradken team

Polycorp is one of the leading rubber liner manufacturers in North America, and the company's PolyStl™ liners are the composite of a special wear resistant steel and high pressure moulded rubber. Similar liner designs have been used for many years in AG / SAG mills up to 32 feet in diameter. Pictured below are the Polycorp team. Pramad Kumar (3rd left) co-authored a paper this evening on PolyStl™ liner development at Chirano Gold Mines in Ghana, which was presented by University of Utah's Raj Rajamani.

In the next booth was Tega, another company supplying liners for primary grinding, autogenous and semi-autogenous mills, and in the photo below representatives were discussing their products with some of the strong delegation from China.

 

The Chinese delegation

Tuesday September 22nd

Another intensive day of presentations from 8am to 8.20 pm, supplemented by 10 new poster displays. Today's sessions covered fine grinding, AG/SAG circuits, HPGR circuits start-up, SAG pre-crushing, process control, and operating practices.

Outotec has a presence at all major conferences, having just committed to sponsoring the next 4 MEI Conferences (posting of September 24th). Hanspeter Erb is hoping to present a paper at Comminution '16, and this morning reviewed the metallurgical performance of the HIGmill™ in a primary milling application. The target was to verify whether the mill could handle coarse feed (3-5mm), ultimately aiming to provide a more energy efficient alternative to ball milling. He is pictured 2nd left with other members of the Outotec team, including Steve Schmidt (left) who I have not seen for a few years. Steve was a regular with Xstrata Technology at MEI's comminution conferences. After 13 years with Xstrata, he moved to Outotec this year as commercial product manager focusing on fine grinding.

Interestingly Hanspeter's paper immediately followed Chris Rule's presentation. Chris, of Anglo American Platinum, showed how ISAMill™ technology has progressed from the original Mount Isa Mines ultrafine grinding applications. Larger ceramic media is now pushing the boundaries of feed size and can offer advantages in grinding efficiencies, product size distribution and internal wear. It is evident that stirred mills are going to play a big part in future circuits, and that there will be an inevitable decline in the use of ball mills.

During the first coffee break I looked in at the poster displays, and caught up with 8 of the 9 delegates from the University of Cape Town.

Also good to see one of my CSM students, Paul Morgan, by his poster on the introduction of Turbo Pulp Lifter System at Karowe Diamond Mine in Botswana. Paul graduated from CSM in 1986 and is now Consultant Engineer-Comminution with South African company DRA, although he works from home in Scotland.

With DRA Director Glenn Bezuidenhout and Paul Morgan

Starkey & Associates Inc. is the name behind a number of the most successful SAG circuit designs in the mining industry today, their projects spanning the globe. Eleven well known testing laboratories work with the company to provide SAGDesign™ testing services and I recently reported on the installation of a test mill in Cornwall, UK. So it was good to catch up with John Starkey, a regular sponsor of MEI's comminution conferences, who invented the SAGDesign™ test, now acknowledged to be a world-class method for grinding circuit design, and is accepted as a standard for ore hardness testing. Starkey & Associates uses the patented SAGDesign™ technology to calculate accurate mill sizes from measurements on a client’s own ore samples, and one of these clients is Russian company TOMS, also a regular MEI comminution conference sponsor. In this morning's session John discussed new projects in Russia for hard and soft ores with SAG mills selected from the results of SAGDesign testing.

John Starkey (2nd right) at the TOMS booth, with interpreter Ekaterina Butko,
Head of Crushing and Comminution Yury Kulikov, General Dorector Arkady Senchenko
and Contract Manager Anna Dergacheva

German company Koppern is a specialist in engineering, manufacturing and technical services for roll presses and HPGRs worldwide. In this afternoon's session Andrew Gardula, Managing Director of Koppern Australia described the first year of operations of a HPGR at the Tropicana Gold mine, in Western Australia. He is pictured right with Managing Director Christopher Schafer and Senior Process Engineer Felix Heinicke. Felix also presented a paper, on Sunday evening, on mathematical-petrographic rock characterisation as support for sizing of HPGRs.

Wednesday September 23rd

The last day got off to an interesting start with a presentation by Paul Staples of Ausenco, Australia, who asked whether SAG mills are losing market confidence. Although a mature technology, a number of recent projects are not achieving nameplate capacity, and he gave a critical review of underperforming AG/SAG mills based on public domain information comparing design expectations with actual operational performance.

With Dave Meadows

The whole morning was devoted to SAG/AG circuit optimisation, and Dave Meadows of Bechtel, USA added to Paul's theme by reviewing the grinding circuit design and performance at Antofagasta Minerals Centinela concentrator in Chile, which was commissioned in 2010. At that time the grinding circuit featured the largest of a kind SAG mill at 12.2m x 7.92m and two 8.2m x 13.6m ball mills. The plant met the nameplate capacity in late 2011 but had some challenges in upstream and downstream plant areas.

It was good to see Dave at the conference, another of my mid-1980s CSM students. For a long time he was with FLSmidth, but recently moved to Bechtel as global manager of metallurgy.

Following the lunch break there were sessions on HPGR optimisation, and General Interest. One of these papers, the 3rd from the end, should provide a useful reference for applied SAG mill operation in the industry. Malcolm Powell of the JKMRC, Australia presented a compilation of common operational issues encountered on SAG mill circuits worldwide. Twenty issues were listed, the symptoms described, and some theoretical background provided upon which the routes to tackle these issues are based.

The penultimate paper was presented by Ricardo Fernandez, of Weir Minerals, Chile. He described how AG or SAG milling frequently becomes a bottleneck in an operation as the generation of critical size pebbles, and the subsequent required re-crushing of these, results in an extra burden for the (S)AG mill in the form of a recirculating load of harder and more abrasive material. HPGR crushing may provide a profitable alternative or addition, allowing the crushed pebbles to be bled to the subsequent downstream ball mill and beneficiation stages, thus freeing desired capacity for the (S)AG mill stage and enhancing overall plant throughput.

In the photo below Ricardo (3rd left) and other members of the Weir team are showing me models, all produced by 3D printing, of their range of crushers.

Before conference Chairman Bern Klein wound up a memorable conference in the late afternoon, McGill University's Jim Finch invited everyone to attend next year's IMPC in Quebec City, with a reminder that the deadline for abstracts is the end of this month - over 700 have already been submitted!

Personally I found SAG '15 to be a very rewarding event and despite the very short breaks between sessions I managed to make a lot of new contacts and catch up with many familiar ones, many being pleasant surprises as no delegate list was available.

With so many papers presented, I could only scratch the surface of the technical content in this report, so I invite those who attended to add their own comments on their own particular highlights and thoughts. And how was the Conference Dinner on the final night, which unfortunately I had to miss?

In thanking the organising committe for a very well organised event, let's not forget the team of enthusiastic student volunteers from the University of British Columbia, who are pictured below with conference registrar Alex Doll.

Back row: Tugba Cebeci, Diana Nakuru, Alex Doll, Yiran Zhang, Hongtao Ma and Nawoong Yoon

Front row: Pei Li, Amit Kumar, Siddhant Kar and Sijia Liu

The conference Proceedings is available via the SAG '15 website, and the next event is provisionally planned to be held in 2019. MEI will certainly be there, and I hope to see many of the delegates from SAG '15 at next year's Comminution '16, which in many ways complements the SAG series.