CEEC Medal winners inspire miners to add value and navigate to success
Newmont is achieving sustainable improvements in its comminution circuits by taking a strategic approach to plant optimisation and design, and sharing leading grinding practices across its 11 operations in the USA, Australia, Peru, Ghana and Suriname.
Business efficiency and production costs have been the main drivers for change in the company’s comminution practices and, through these initiatives, Newmont has been able to reduce its production costs. Examples include addressing power consumption at Ahafo gold mine in Ghana and reducing grinding media usage rates at operations like Twin Creeks (USA) and Tanami (Australia); boosting throughput and metal recoveries at Boddington; and increasing throughput at Kalgoorlie Consolidate gold mine (KCGM).
Newmont’s Ahafo team (L to R): Plant Metallurgists Jones Awuah and Pierre Mensah; Project Metallurgist Peter Dyon Effah; Metallurgical Superintendent Emmanuel Asakpo; Senior Metallurgist Isaac Duffour; Laboratory Metallurgist Enock Amponsah; and Graduate Metallurgist Trainee Francis Tenkorang.
Several of these optimisation efforts have involved 2017 CEEC medal winners from Newmont - internal comminution specialist Aidan Giblett and (Australia’s) Principal Advisor Processing Steven Hart - in some capacity. They are often involved in ideas generation and definition for site improvement projects in collaboration with site teams. Once the ideas are developed and defined, their roles incorporate support of operations people who take on and deliver the projects. Newmont’s well defined Full Potential program also allows other team members to participate in the ideas generation and definition stages, supporting a company-wide focus on optimisation.
Mr Giblett has 25 years’ experience in operations, project development and corporate roles, predominantly with major gold mining companies. For the past 12 years he has worked for Newmont’s corporate Technical Services group. In his current role he provides subject matter expertise in comminution to the company’s operations and projects around the world. Mr Giblett has been involved with site optimisation studies at operations in Ghana, Peru, North America, Indonesia and Australia. His role also incorporates identifying emerging technologies and best practice in comminution around the world and incorporating these into Newmont’s operations.
Mr Hart has 29 years’ operational and design experience, primarily in gold and base metals processing. He spent six years with Boddington during the design, commissioning and ramp-up of the operation, culminating in just over 12 months as the Processing Manager. In his current role of Principal Advisor Processing, he has worked closely with the Tanami and KCGM operations, contributing to plant improvement projects in comminution, metal recovery and cost reductions. A significant component his current role is to work closely with the site-based metallurgical and processing teams on longer term strategies as well as research and development opportunities.
The approach
Newmont’s strategic approach to plant optimisation and design incorporates the Full Potential program and the efforts of technical staff to identify and rank emerging technologies and industry developments to implement and promote the best practices across its operations.
“This program has been in place for a number of years and is very effective. At the core of the program are subject matter experts and processes to screen, evaluate and rank any number of site optimisation initiatives,” Mr Giblett said.
“The Full Potential program gives sites the mechanisms to get the projects prioritised, resourced and implemented. A lot of this is due to the rigour the program puts on defining the value that will be created by the project. Value creation is a key guiding philosophy of the corporate Technical Services team.
“The most promising initiatives are selected, studied and implemented. In a large number of instances, the site teams have already identified the best opportunities. The program is very effective at elevating good opportunities and getting them implemented in a timely fashion. This is where we often see comminution focused opportunities rise to the top, based on economic impact. Often these types of initiatives make a real difference to the mine site economics.”
Mr Giblett points to project team composition as another critical success factor.
“We have usually involved cross-functional teams in these projects, drawing on technical, maintenance and operational experience. Having a diverse range of people involved in the improvement projects helps with problem solving as well as ensuring a successful implementation,” he said.
“We also look outside the project teams and even outside the organisation. Plant operators make invaluable observations about plant performance; their input is essential. Vendors have a lot to offer too, as they are often the conduit for new knowledge based on product development or practical experience from other sites.
“Anyone else who is a constructive thinker, irrespective of the role – people who question assumptions and challenge logic are really good to have around. People from outside the processing space can make useful contributions as they see things, constraints or otherwise, that may not be obvious from within the processing bubble.”
Leadership is another critical success factor. Without managers who support their teams, back high-potential ideas, and encourage the generation of new improvement ideas, there is no change. Of course, the ideas need to be framed appropriately.
“I don’t think you can beat a clearly presented value proposition. Know the science you intend to exploit – ideally in simple terms – be clear to the expected value, and have a well thought out implementation plan that includes securing stakeholder buy-in,” Mr Giblett said.
“When you have a system that forces you to put the dollars around the potential, it helps support them to come to fruition. It builds on knowledge, brings new insights, and boosts performance and productivity.”
Results
Although one of Newmont’s biggest challenges, increasing the mill throughput at Boddington was also one of its greatest success stories, according to Mr Hart.
Newmont’s Boddington mine produces gold and copper concentrate and is one of Australia’s largest producing gold mines.
“The operation demonstrated early on that it could exceed the design throughput rate, with up to 130,000 tonnes per day processed at times during the first year of operation. However these rates could not be sustained due to equipment reliability issues, and this has been the key focus of our operation for the past five years,” he said.
“Needless to say we have taken the annual throughput from 35 million tonnes to more than 39 million tonnes in FY2017, and there are still more improvement opportunities that have been identified.
“Working on the ball milling circuit, we have also seen this result achieved with a reduction in final grind size due to increasing the power consumed by the high pressure grinding rolls circuit, finer feed to the ball mills, and a smaller ball charge addition to the ball mills (as a result of the finer feed).
“This has had a positive impact on metal recoveries for the operation at the same time that throughput has been increased, which is not always the case with operations. Whenever you have a good focus on grinding circuit efficiency or even metal recoveries, you are working at improving energy efficiency by default.”
Emerging technologies
New technologies could boost the productivity of Newmont’s comminution circuits even further and Mr Giblett points to a number of emerging technologies that look promising.
“These include ore sorting and pre-concentration technologies to reduce the amount of material that goes through fine crushing and grinding. We need to develop desktop characterisation procedures that define ore amenability to these processes early in the project life, without the need to collect and process large ore samples at pilot scale. Once we can do that we might expect to see a larger shift in how the industry operates,” he said.
“Separating at coarser crush or grind sizes, and with improved liberation, will be a key to the future success of low-grade, high-tonnage operations. Reducing our energy footprint is high on the agenda at Newmont.”
CEEC Medal
Committed to documenting and sharing Newmont’s comminution improvements, Aidan Giblett (internal comminution subject matter specialist) and Steven Hart (Newmont Australia’s Principal Advisor Processing) produced a paper, ‘Grinding Circuit Practices at Newmont’, which they presented at the AusIMM’s Mill Operators’ Conference at Perth in 2016. Giblett and Hart were awarded the operations category of the 2017 CEEC Medal for their efforts.
The CEEC Medal is a prestigious annual award that recognises the most outstanding published papers, articles or case studies that profile energy-efficient comminution and mineral processing strategies. Nominations are reviewed by the CEEC Medal Evaluation Committee for applicability, supporting research and documentation, prospective impact, potential energy savings, and presentation style.
Established by the industry, for the industry, the Coalition for Energy Efficient Comminution (CEEC) is an international, not-for-profit company committed to sharing energy efficient mining processes to help lower costs, increase productivity and improve shareholder value. To drive this mission, CEEC has established a collaborative global network of mining leaders, technical experts and researchers.
CEEC CEO Alison Keogh said in 2017 there were a record number of nominations and the competition was extraordinarily high.
“Nine of the 18 papers put forward for the CEEC Medal were potential winners, demonstrating that many individuals and organisations are striving for improvements and advances in minerals processing and comminution. That’s good for the industry. CEEC is proud to share this work and inspire miners and researchers around the world to help drive incremental and transformative change,” she said.
“Aidan and Steven’s paper highlighted Newmont’s challenges and approach to improving grinding practices across its 12 operations around the world.
“An exceptional contribution to the global mining industry’s body of knowledge, the paper provides practical solutions and clear guidance on reducing risks and improving performance.”
Mr Giblett said Newmont had significant experiences in plant optimisation and design. He and his colleagues wanted to share the insights from their diverse project experience and their paper was one means of doing that.
“One of the things the industry doesn’t always do as well as we would like is documenting and sharing its experiences, so we wanted to do that – celebrate some successes, promote and contribute positively to conversations around effective comminution circuit selection, design and operation,” he said.
Mr Giblett said although some of the initiatives highlighted in the paper had short delivery times, the more significant projects took between two and five years from concept to execution.
“There is often some time required to effectively communicate the concept and get enough buy-in to progress the project with real purpose,” he said.
“A lot of times you might be implementing something that was raised or identified some years back, but never got off the ground. Sometimes you need to be patient and wait for the right alignment of business priorities and personalities to get some real traction.”
Plant optimisation – top tips for project success
- Recognise the business driver
- Support innovation and new practices through leadership
- Implement effective systems to screen, evaluate and rank site optimisation initiatives
- Establish cross-functional project teams
- Engage with stakeholders and attain buy-in
- Canvas widely for improvement ideas and perspectives.
Top 3 improvements projects
- Increased SAG mill efficiency at Ahafo surface gold mine, Ghana
- Grates and turbo pulp lifter combination
- Total discharge end optimisation and strong improvements in efficiency
- Grinding media optimisation work (size and chemistry), all Newmont sites
- Shows that there can be significant opportunities in this area
- In the absence of rigorous assessment, existing rules of thumb and assumptions around what is optimal can be inaccurate
- Mine-to-mill or mill feed size optimisation, Boddington surface gold, copper mine, Western Australia
- Increasing the amount of fines in the mill feed
- Improving shovel dig rates and improving the mine/mill interface at the primary crusher
- Taking the primary crusher throughput from 120,000 tonnes per day to well over 150,000 tonnes per day.
Driving advances across mine sites worldwide
Mine sites scattered across the world may not often have the opportunity to share practical improvement stories like those published by Newmont. But knowing what colleagues are doing can provide good ideas, and collaboration pays dividends.
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