A Complex Lunch with Dr. Kathy Ehrig

The Adelaide Branch's first technical lunch of the year took off to a flying start with Dr. Kathy Ehrig

The Adelaide Branch kicked off the 2019 event calendar with 85 people attending our much anticipated February event held at The Pavilion on Valentine’s Day. It was pleasing to see such a diverse group of students and industry professionals gather together after a few months off over the festive season. Guests had the opportunity to chat and network with new faces, old time colleagues and friends over a couple of drinks prior to the formalities. Fresh to the throne, Chris Sykes, our newly appointed chair, brought his forever cheerful and smiling nature to the mic with a warm welcome to all. Chris recognised the scholarship winners for the Premium Education Endowment Fund, Playford Trust Memorial Scholarship and Professional Excellence Awards. It was truly inspiring seeing such a high calibre of minerals professionals right here a part of the Adelaide Branch. Lastly, we congratulated our lucky door prize winners James Basbas and Sean O’Sullivan!

Next to the stand, Dr Kathy Ehrig, Principal Geometallurgist for BHP Olympic Dam, presented on the Olympic Dam ore body and its geological composition. Kathy set the scene for the talk by exploring the definitions of the term’s ‘complexity’ and ‘complicated’, what they really mean in the geological and mineralogy sense, and how the term ‘complex’ is often misunderstood. She highlighted that the roles of engineers and scientists are “to reduce complexity and transform complicated systems into simple systems’’ – a feat not always achieved. Furthermore, she reminded the audience that the term ‘complex’ is often used as an excuse for poor performance in todays workforce.


the roles of engineers and scientists are to reduce complexity and transform complicated systems into simple systems

Kathy took us back to the early processes implemented at Olympic Dam and discussed how the mineral classifications of the various rock types may have contributed to masking the Olympic Dam orebody as a complex system. Kathy argues that the inconsistent use of these geological classes are complicated, and that the ore body itself is not complex – due to the simple chemical compositions of the various breccia types.

Kathy concluded that neither the ore body, mineralogy or processing at Olympic Dam are complex, but indeed complicated. The breccia textures and ore deposit genesis is not a complex theory but is certainly complicated, the mineralogy is simple – even though it has been perceived to be complicated for a long time and the processing in most parts is simple – however recycle streams complicate things.

Kathy’s presentation can be viewed on the AusIMM Adelaide Branch webpage or the Adelaide Branch Facebook page, Ehrig et al Feb2019 AusIMM Adelaide Branch Presentation.

We thank Kathy for her time and effort for always putting on a fantastic show at our February event and look forward to welcoming her back for future events. Many thanks also extend out to the numerous guests who attended our first event for what is to be an exciting year for mining in South Australia.


Jason Hodge – Branch Committee Member

2019 February Event Photo Gallery



Branch Partners 2019


Technical Lunch Partner 2019

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