Foundations for the future: stability and sustainability for the long term at Olympic Dam

  • By Chris Barnesby, GM Surface, Olympic Dam

This article was originally a presentation delivered at the Copper to the World Conference in Adelaide, July 2019. It has been edited for publication on the AusIMM Bulletin website.

Many resources professionals today share a common belief: that the future depends on us embracing change and new technology in a relentless pursuit of innovation.

At BHP, we know that these are the keys to making our operations at Olympic Dam and around the world safer, more productive, more inclusive, and able to deliver greater shared value for our people and communities, every day.

In this article, I will cover a few initiatives and projects underway to help us achieve these goals.

I have been at BHP for three decades. I have worked across the globe, in different roles, at different levels, in different industries and businesses, through lots of changes and challenges, and there are few places that offer the technical complexity, opportunities, and exciting potential of Olympic Dam.

Olympic Dam is Australia’s largest uranium mine, one of the top copper mines, and a substantial producer of gold and silver. BHP produces these four polymetallic products (of 42 known in the mine), and we are the only site, perhaps in the world, that takes them from the earth-to-end product in one incredible operation. 

The operation is vast—roughly five kilometres long, four kilometres across at its widest point, and more than a kilometre deep. Our workforce is in excess of 3500, but last year we had more than 11,000 people come through the gates. And we are proud of our legacy— we have just celebrated 30 years of supporting jobs for tens of thousands of people and delivering tens of billions of dollars of investment, taxes and royalties to South Australia.

Moving forward, we need to innovate with purpose, to apply technology intelligently, and to always remain focused on what is most important: the safety of our people, the culture of our teams, and the long-term sustainability of our business.

So how are we doing this at Olympic Dam?

Improving safety underground

I will start with safety. Safety always comes first.

In any underground operation, one of the primary health and safety challenges is air quality. Many underground mines use diesel-powered vehicles for transport, and the diesel particulate matter (DPM) produced in the exhaust is harmful to health, which means making sure the mine is well ventilated is fundamental.

Over the past few years, our own team has developed and implemented (with the help of OEMs and suppliers) a number of revolutionary filtering methods to reduce exposure to our people, including:

  • retrofitting exhaust filters on all light vehicles and heavy machinery
  • establishing higher standards requiring all new vehicles to be fitted with filters before they arrive
  • kicking off a light electric vehicle trial that we announced at Copper to the World last year.

We set an ambitious target – way ahead of industry standard – not just to reduce but to eliminate exposure to DPM from machinery underground. Our results thus far have been an over two-thirds reduction in DPM in our underground operation. We have also removed the need for the mandatory wearing of dust masks underground. And we are not done making improvements.

Advanced blister tapping

Any time you have people working with molten materials, safety is a key issue, and you want to ensure you have the best equipment and technology in place.

The tapping process requires manual burning of tap holes using an oxygen lance, and we needed to find better, more advanced solutions to reduce operator exposure and improve our overall process.

After studying a number of technologies, we identified and are designing a new advanced blister tapping solution which uses cutting-edge technology that will improve safety in a number of ways. The new technology will:

  • reduce operator exposure to a number of risks, including line of fire and heat exposure by 80 per cent (493 hrs).
  • improve the stability of our processes and equipment, by reducing variability when opening the tap holes, improving tap hole integrity, and reducing the frequency of tap hole insert replacement.
Current process (above).
Ultimately, the technology has the capacity to completely automate direct interactions with the molten materials and remove people completely from the line of fire.

These efficiencies will contribute to increasing production and reduce maintenance. Ultimately, this technology has the capacity to completely automate direct interactions with the molten materials and remove people completely from the line of fire.

This is a highly scalable solution that can be transitioned in our operations safely and efficiently, and it is a huge investment in our improvement and growth strategy.

Automated cathode stripping machine

Our refinery is the final step in the copper refining process, where high-quality copper cathode sheets are produced for domestic and export customers around the world.

We recently announced an AUD$140 million investment to replace the refinery crane, refurbish key equipment and install an automated cathode stripping machine (CSM).

The CSM detaches the copper cathodes from the stainless steel mother plates, then samples, stacks, weighs and labels the cathodes ready for sale.

This is a repetitive task that requires precision and accuracy.

With this substantial investment, the new automated CSM will be fit-for-purpose, safer and more efficient, with scope to increase overall output from 180 to 340 plates per hour.

Automated CSM.

This will also be, in effect, Olympic Dam’s first robots, sourced from a specialised supplier in Canada and scheduled to be delivered in mid-2020.

This is a prime example of automation – ground-breaking technology being used to improve safety and productivity and enhance the workplace experience for our people.

And, as part of the overall investment in our refinery, this is another positive step towards improving our reliability and setting a platform for future growth.

Heap leach trial

Finally, I have saved the best for last with another above-ground example, because we all know that is where the real magic happens.

In 2012, BHP began a heap leach development program to determine if heap leaching could be deployed at Olympic Dam at scale to improve processing efficiency and deliver a commercially viable outcome.

The trial was undertaken at a purpose-built facility in Wingfield. In basic terms, we built a small-scale heap leach facility as you can see in the picture below.

Heap leaching works by creating a large stockpile of ore – the heap – and drip-feeding acid through the heap to leach out the metals contained within it. BHP uses this process at copper operations in Chile to positive effect – but the polymetallic properties of Olympic Dam present unique challenges and opportunities.

At Copper to the World 2019 we announced the successful completion of the R&D program with promising results. We produced 19 tonnes of good quality copper. Most of this material, except a few commemorative trophies, went right back into the smelter and off to customers from the refinery.

The trial confirms that the heap leach process could be a viable commercial option at scale for Olympic Dam, and the trials were completed in the presence of salty water, which means it could reduce our future use of potable water.

South Australia should be acknowledged for the role it has played in helping support this R&D and the development of this unique flow-sheet and intellectual property. We would also like to recognise our partner Bureau Veritas for their collaborative approach. The operation was executed with safety in design, construction and operation, and, as a result, we experienced no significant issues nor incidents in the more than six years of the trial.

Whether we deploy heap leach at Olympic Dam is a matter for future consideration, as there are many factors involved. As it stands today, we have confirmed the viability of the technology which has the potential to underpin long-term growth options for Olympic Dam.

In the more immediate future, our short-term growth study is progressing well. The Brownfield Expansion Project, or BFX, which forms part of BHP’s Olympic Dam resource development strategy, was declared a major development by the state government earlier this year.

The project team is currently studying a range of options to potentially increase production to between 240 and 300 kilotonnes per annum in the first phase, with a view to seeking approval for capital from the BHP Board late next year.

In the meantime, the team remains firmly focused on setting a solid platform for a sustainable, long-term operation that can support staged growth. Technology and innovation will be critical to unlock value through debottlenecking and latent capacity opportunities.

As we work through these options, the constant is that Olympic Dam is a globally significant resource, with potential to deliver tremendous value for BHP and South Australia for decades to come.

Culture and conclusion

But we are only ever as good as our people.

Technology and innovation can set us up for growth, help us produce more safely and reliably, allow us to employ people in better jobs, different jobs, jobs that require new skills and abilities, and allow more people to gain employment in mining than ever before.

At BHP and Olympic Dam, we are driven by a culture based on Our Charter values, including integrity, respect, accountability, and sustainability.

Our people are encouraged to pursue their ideas and create and embrace the tools they need to continuously improve.

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