Monday, 16 January 2017

The Increasing Importance of Physical Separation Methods

Physical Separation '17 is building up to a must-attend event if you are involved with physical separation of minerals and coal. Physical separation features in almost every mineral processing circuit, encompassing a broad range of techniques and technologies including hydrocyclones, gravity concentration methods and thickeners, all of which make use of the inherent density difference between two mediums, as well as magnetic separation, and the increasingly important ore sorting technology.
One of the leading practitioners in the gravity concentration field is Sandy Lewis-Gray, Technical Director of Gekko Systems, Australia (see posting of 16 March 2015), one of the conference sponsors, who will present the first keynote at the conference, showing how opportunities for enhanced physical separation performance can now go beyond the common practice of optimising unit operation. Improved options exist for feed preparation ahead of the physical separation stage, enabling higher performance and lower cost outcomes for physical separation flowsheets and technologies.
Sandy and Elizabeth Lewis-Gray of Gekko Systems
Sandy will also co-author a paper with fellow Australian sponsor CRC Ore, who will describe the development of a new generation of comminution devices which can produce much steeper product size distributions than with conventional machines, and combined with precise classification will produce feeds which are well suited to gravity concentration and should also reduce flotation losses at both coarse and fine sizes. The use of such new applications in breakage technologies, combined with mineral liberation analysis to optimise liberation prior to the physical separation stage, provides options for pre-concentration and gangue rejection as well as better separation efficiency. The use of low cost gangue rejection and pre-concentration can be an intermediate step between mining and processing that allows lower cut-off grades in the mine whilst delivering higher grades to the mill, and conference sponsor Steinert Elektromagnetbau will assess the economic impact and viability of upgrading ores by pre- concentration using ore sorting.
Electronic ore sorting is becoming increasingly used, due to the development of rapid sensors in such sorters, but preconcentration prior to grinding is nothing new, and dense medium separation has long been an accepted method for treating coal and for early gangue rejection from certain metallic and non-metallic ores, including diamonds. Prof. Tim Napier-Munn (posting of 12 May 2014), former Director of Australia's JKMRC and a current CEEC Director, has many years of experience with dense medium cyclones, which were first patented in the 1940s, and will present the second keynote lecture at the conference, summarising the history of the process, considering its current status in mineral and coal processing, and suggesting ways in which the process might evolve. 
Tim (right) with fellow CEEC Director Mike Battersby at Comminution '14
So, there is much to look forward to in Falmouth in June. We will be putting the provisional programme together later this month, so it is not too late to submit an abstract for presentation at the conference, which immediately follows Computational Modelling '17 at the same venue.
Current Physical Separation '17 sponsors

16 comments:

  1. They have ALWAYS been important.... but developing slowly. Perhaps the importance of Chinese options of basic separation equipment is the big news over the past few years, and how to deal with the Chinese to get the machinery and quality you require!
    Steve Canby, MinEx Associates, UK

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  2. The art of physical separation is sometimes just a "taken" without actually understanding it, or more importantly understanding why it doesn't work!
    David Goldburn, SGS, UK

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  3. To develop more physical separation in ore processing, we have may be to face reagent seller lobbies ??
    Mostafa Benzaazoua, Université du Québec, Canada

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  4. One area that has lagged has been development of higher capacity options.
    Mike Albrecht, Roberts Companies, USA

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  5. Agree with Mike re the development of higher capacity options. The opportunity has been well illustrated with lab and pilot work, taking the next step requires equipment with the throughput capability and maintainability to make the step (with risk of the new) worth taking.
    Bob Seitz

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  6. I am happy that gravity separations is getting another look; lectures by experts like Tim would make the principles and theory behind the process more clear; as some have already commented, how to we take it forward so that reagent based processes can be minimised, if not eliminated. Proper attention to water consumption is also needed.
    Rao,T.C.

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  7. Nuray Karapınar17 January 2017 at 06:30

    Because of the environmental challenges with chemicals, very fine size of the materials and high energy need in grinding circuits, physical separation techniques are as much as important than be ever.
    Nuray Karapınar, MTA, Turkey

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  8. There has been a long time since physical separations are part of most Mineral Processing Industries. Of the many available unit operations, spiral still leads the way. But EGC's like MGS, Knelson, Falcon .... to some extent Kelsey Jig still needs acceptance application area.
    I want to know what is the benchmark for these unit operations or how we can compare these in the present scenario about their existence.
    Dr. Rama Murthy Yanamandra, Tata Steel, India

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    1. Rama, ultimately is horses for courses. The MGS, Knelson/Falcon, Kelsey jig all may play a part in the process, but each one has a pro/con to its use. Unless you test the ore on each one at an optimised setting you will never know its benchmark, as each ore is different. Spirals lead the way for roughing- they are cheap and take up little floor space and can have numerous starts so can push high tonnage. If you are buying through a supplier who sells Falcons/Knelsons you are likely to end up with one in the circuit....
      David Goldburn, SGS, UK

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  9. They are very important because some are environment friendly and cheap in design also in mantainance!
    Salom Hamunyela, Namibia

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  10. Mineral processing is essentially physical separation. Even floatation is also physical separation albeit in a little different way. But I agree with Mike that achieving high unit capacity is a problem and this leads to higher unit operating cost. But it indeed calls for further frontier area research as the world at large beyond the mining community will not tolerate environmental pollution from operations. Only Physical separation processes could meet environmental standards but this needs to be done cost effectively.
    Arabinda Bandyopadhyay, CDE Asia Ltd, India

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  11. Physical separation techniques are continuously evolving and it's quite obvious that it's a cheaper option. Considering present environmental situations it's today's necessity to look into options that were already present and reinvent them using technology that is present now. In this context introduction of dry benificiation can be good example of how it's becoming a topic of discussion again. We must look for other such options.
    Om Dwivedi,Mineral Engineering,Indian School of Mines.

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  12. Not sure I agree with the comment that spirals take up "little floor space" at what, say 10 tph for a triple start unit ! Also couldn't agree with the comment that reagent seller lobbies may be a hinderance. It is disappointing that Barry's excellent conferences don't seem to see particpation from Mineral Technologies from Aus., nor FLS who now own Knelson concentrators although. You'd thank they'd like to showcase their latest and greatest. Barry - have a go at them if you're at SME this year?

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    1. Totally agree with you anon, I have never seen any lobbies from reagent suppliers to limit the use of physical separation methods. Will have to put you right on MEI Conference participation, however. Mineral Technologies USA has been a regular participator at MEI Conferences, including Physical Separation '15 where they presented a paper. FLSmidth is one of our regular conference sponsors and will be out in force at Flotation '17 later in the year.

      I will be at SME next month. Will you be there? It would be good to know who I am speaking to- a reminder to everyone to leave name and affiliation if possible.

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  13. Bandyo / Mike. With regards to capacity, we have been working on this for the MGS. Having focused on its basic principle of scrape then release, scrape then release, we have been able to move away from the restrictive single spiral of scraper blades pulling a limited mass to concentrate and instead are able to use the entire surface of the drum. We have also been able to open up a clear pathway to tails by use a our simple passive tailings scraper system. I think you will be mightily impressed !
    Treve Mildren, Gravity Mining Ltd, UK

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  14. Good to see so many comments from experts on this nice aspect of Mineral Processing.
    Reducing comminution costs/more efficient and high capacity fine particle physical separation processes and cost effective dewatering(filtration systems); all leading to maximum recoveries of values are the future to
    make mineral industry more profitable
    Rao,T.C.

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