Energy Management Options for Miners - Tools to Tackle Energy in Comminution and Beyond

CEEC is excited about the many advances occurring that offer solutions or potential advances for miners to tackle energy use, reduce operating and capital costs, and enhance productivity.

There are many ways to improve mining energy efficiency and productivity. Comminution is a key part of this, along with complementary solutions.

Comminution is to be the subject of a feature in an upcoming AusIMM Bulletin due for publication in June 2017 (to be available soon from here: https://www.ausimmbulletin.com/).

Here is a snapshot of some leading energy efficiency and productivity opportunities and solutions, in comminution and beyond:

  • High intensity selective blasting to improve blast fragmentation can form part of a mine-to-mill strategy to optimise the particle size fed to AG/SAG mills, thus improving throughput and specific energy consumption (Brent et al, 2013).
  • Pre-concentration using screening, bulk ore sorting or gravity concentration (jigging or dense medium separation (DMS)) can remove coarse barren or low-grade material prior to comminution and concentration. Sorting technology is also advancing.
  • Dry comminution processes may offer energy efficiencies, including Vertical Shaft Impact (VSI) crushers, High Pressure Grinding Rolls (HPGR), and Vertical Roller Mills (VRM). These methods produce less fines but achieve the desired product size, minimise overgrinding and use less energy.
  • Stirred mills offer better energy efficiency than conventional ball mills for finer grinding.
  • Improved classification can provide a narrower product size distribution, saving energy in unnecessary production of slimes, and replacing cyclones with fine screens may improve the efficiency and capacity of closed grinding circuits.
  • Novel comminution technologies may offer improved energy efficiency and liberation performance. Some currently being researched include electrical breakage, microwave treatment and new grinding mechanisms, but these are far from routine industrial practice.
  • Improved wear component design and methods, such as mill liners and relining to reduce downtime and increase productivity.
  • Intelligent decision-making based on big data analytics can allow optimisation of processes to increase throughput, reduce energy consumption and limit downtime.
  • Modular, low-height circuit configurations can take plant closer to open pit or underground mining and divert waste earlier, saving energy in transport and downstream processing.
  • Improving autogenous grinding through improved blast control and partial pre-crushing with pebble extraction to provide free grinding media to second-stage pebble mills: When integrated with early gangue rejection methods, this has potential to dramatically lower energy use and operating costs.
  • Smart power reticulation and management, including drawdown, power balancing and supply planning are important to optimise energy use and reduce energy waste within sites (Australian Mining, 2013).
  • Coarse flotation technologies offer the potential of grinding to a coarser size, greatly reducing the energy required.

Examples of some of this work include:

  • CRC Ore’s Grade Engineering concept
  • DMS, a mature, proven and widely-used technology including in base metal pre-concentration, such as in lead-zinc operations at Mt Isa and McArthur River in Australia.
  • Ore sorting approaches, such as Steinert’s testwork at Norseman Gold’s Bullen operation in Western Australia showed low-grade stockpiles amenable to pre-concentration using XRT sorting technology, decreasing mill feed by more than 50% (Parry and van Wyk, 2016).
  • Large-scale ore sorting opportunities such as that outlined in work by Ausenco, Foggiatto et al (2014): removal of gangue by large-scale ore sorting ahead of comminution increased mined ore and processed grade, resulting in a substantial 20% to 30% reduction of specific energy per tonne of metal produced.
  • Modular solutions, such as Gekko’s Python modular ore concentration system recently commissioned in Canada’s remote Arctic Circle at Hope Bay (Gekko, 2017).
  • Mill equipment approaches, with full-scale plant trials demonstrating 3%-4% more throughput for a given mill power over the life of mill liners (Yahyaei et al., 2015).
  • Smart approaches to power management, and options to reduce and mitigate supply and pricing risk (Energetics, 2017).

There are other complementary and enabling potential “shift-the-dial” advances emerging, including:

  • Digital disruption, such as through hackathons to catalyse change - in some case prompt solutions for miners are resulting, such as PETRA Data Science’s solutions which led to a partnership with Newcrest supporting transformative downtime prevention at the Lihir mine in PNG (Australian Financial Review, 2017; Unearthed, 2017)
  • Tailings advances and rethinking to minimise power and water consumption, such as Goldcorp’s potentially transformative EcoTails (2017) technology.

Our shared knowledge of the solutions is always building. If you would like to contribute more ideas or forward some published papers offering solutions, we warmly welcome you to email us at This email address is being protected from spambots. You need JavaScript enabled to view it..

A full article will appear in the upcoming AusIMM Bulletin. CEEC proudly acknowledges its visionary sponsors, and gives thanks to contributing authors: Greg Lane, Robert Braun and Bianca Foggiatto of Ausenco, Dr Walter Valery and Kristy-Ann Duffy of Hatch, Prof Malcolm Powell and Dr Grant Ballantyne of JKMRC, Dr Mary Stewart (also CEEC Director) and Helen Weatherell of Energetics, and CEEC Directors Joe Pease, Dr Zeljka Pokrajcic and Prof Tim Napier-Munn.

Tap into CEEC’s free Resource Centre and search for more on these topics by keywords of interest here: https://www.ceecthefuture.org/resource-center/

Join the Energy Conversation via the LinkedIn Group: CEECthefuture.org

 

REFERENCES

Australian Financial Review (2017). The hackers that helped Newcrest fix Cadia (Australian Financial Review). News article, 17 March 2017, Available at [http://www.afr.com/business/mining/the-hackers-that-helped-newcrest-fix-cadia-20170316-gv058k#].

Brent G F, Dare-Bryan P, Hawke S and Rothery M, 2013. Ultra-high-intensity blasting – a new paradigm in mining, in Proceedings World Gold 2013, pp 395-400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Energetics (2017). Energy is a cost you can control. Web article by Leigh Rostron, Available at [http://www.energetics.com.au/resources/latest-news/climate-change-matters/energy-is-a-cost-you-can-control], Accessed 6 April 2017.

Foggiatto B, Bueno M, Lane G, McLean E and Chandramohan R (2014). The economics of large scale ore sorting. In Proceedings IMPC 2014: XXVII International Mineral Processing Congress, Santiago, October 2014.

Gekko (2017). Gekko’s modular gold plant benefits Hope Bay. Gekko Systems, 6 March 2017 news article Available at [http://www.gekkos.com/news/gekko%E2%80%99s-modular-gold-plant-benefits-hope-bay], Accessed 7 April 2017.

Goldcorp (2017). Goldcorp’s EcoTails Technology Challenges Mining’s Historical Relationship with H2O. Web blog, 29 March 2017, Available at [http://www.goldcorp.com/English/blog/Blog-Details/2017/Goldcorps-EcoTails-Technology-Challenges-Minings-Historical-Relationship-with-H2O/default.aspx], Accessed 25 April 2017.

Innovation State of Play (2014). 2014 Report. Available at [https://www.innovationstateofplay.com/wp-content/uploads/2016/05/SOP2014.pdf], Accessed on 6 April 2017.

Mining Magazine (2017). PETRA unearths solution for Lihir. Mining Magazine article, 21 May 2017, Available at [http://www.miningmagazine.com/equipment/mineral-processing/petra-unearths-solution-for-lihir/], Accessed 25 April 2017.

Parry A N & van Wyk G (2016).  Upgrading low-grade gold ore stockpiles by preconcentration using ore sorting – an assessment of the economic impact and viability. 13th Mill Operators’ Conference, Perth, Western Australia, 10-12 October 2016. The AusIMM, pp 179-189.

Unearthed (2017). 100 hackers dig through data to unearth valuable insights for Newcrest Mining. News article, Available at [https://www.unearthed.solutions/100-hackers-dig-through-data-to-unearth-valuable-insights-for-newcrest-mining/], Accessed 25 April 2017.

Yahyaei, M., Powell, M.S., Toor, P., Tuxford, A. and Limpus, A. 2015.  Relining efficiency and liner design for improved plant performance. Minerals Eng., 83, 64-77.

Additional References of Interest

Deloitte (2016). Energy Management - The bottom line. Driving value through energy management in mining. Report Available at [https://www2.deloitte.com/au/en/pages/energy-and-resources/articles/driving-value-through-energy-management-mining.html].  Accessed 6 April 2017.

Energetics (2017). Looking to hedge energy contracting risks in 2017? Consider a corporate renewable power purchase agreement. Energetics website article, Available at [http://www.energetics.com.au/resources/latest-news/climate-change-matters/managing-energy-contracting-risks-in-2017-with-cor].  Accessed 7 April 2017.

Manouchehri, H.R., (2015). Towards Sustainability by Bridging the Gap in Comminution – From Finely Crushed Ore to Stirred Media Milling, in Proceedings of  SAG Conference, 20-24 September 2015, Vancouver, Canada, 16 pp.

Nasirov and Silva (2015): “Diversification of Chilean Energy Matrix: Recent Developments and Challenges”, International Association for Energy Economics, Fourth Quarter 2014, pp 27-31.Parry A N & van Wyk G (2016).  Upgrading low-grade gold ore stockpiles by preconcentration using ore sorting – an assessment of the economic impact and viability. 13th Mill Operators’ Conference, Perth, Western Australia, 10-12 October 2016. The AusIMM, pp 179-189.

Toronto Sun (2016). Ontario electricity rates fastest rising in North America. News Article 29 Feb 2016, Brady Yauch, Available at [http://www.torontosun.com/2016/02/29/ontario-electricity-rates-fastest-rising-in-north-america], Accessed 7 April 2017.

Yahyaei, M., Powell, M.S., Toor, P., Tuxford, A. and Limpus, A. 2015.  Relining efficiency and liner design for improved plant performance. Minerals Eng., 83, 64-77.

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