Image: Isaac Plains Coal Mine: Achieving record through-put rates and yields

Minerals & Metals3 min read

Isaac Plains Coal Mine: Achieving record through-put rates and yields

Queensland, Australia
Isaac Plains Coal Management (2008-2016) Stanmore Coal (2016-2019)
2008 - 2019

In 2008, the Ausenco team took over full responsibility for the Operations and Maintenance of the Isaac Plains Coal Handling and Preparation Plant (CHPP). A comprehensive audit led to significant engineering and process changes that significantly improved plant production, optimising throughput and increasing return on investment.

The Challenge

The Isaac Plains Coal Mine is located in the Bowen Basin region of Central Queensland, Australia, approximately 150 km southwest of Mackay. The open cut mine deposits provide the plant with a combination of metallurgical and thermal coal for processing.

In 2008, our team was engaged to take on full responsibility of the Coal Handling and Preparation Plant (CHPP) operation, from Run Of Mine (ROM) to train load-out. We were challenged to improve plant production by increasing plant throughput, efficiency, and availability.

In 2012, we were re-engaged to validate and optimise the existing management and maintenance functions at the plant, identifying areas of opportunity for the business through optimisation.

The plant went into care and maintenance in 2015. In 2016 it was restarted under new ownership. Ausenco assisted the new owners to re-commission the plant before resuming full responsibility for the operations and maintenance of the facility.

The Better Way

A clear and detailed picture of the entire operation was critical to finding opportunities to optimise production, and where the right engineering, training and management would ensure results our clients needed.

A comprehensive review of the entire operation allowed our team to immediately identify a number of bottlenecks that prevented the plant from reaching its design capacity and anticipated production targets. Our team determined that the feeder-breaker crushing equipment was undersized, resulting in regular breakdowns that reduced the annual throughput of saleable product. Upgrading the secondary sizer provided the necessary nameplate throughput, and more consistent equipment availability.

After planning, procurement, and commissioning of the upgraded crusher, plant throughput increased from 372 t/h to 500 t/h – a 34% improvement. Reduced wear and stress on crusher components, and a series of revised maintenance routines, resulted in a 50% reduction in maintenance costs for the crusher. Additional issues with the teetered bed separator led to further modifications that would significantly improve yield.

As part of our commitment to continuous improvement, our team also conducted an asset management audit to review existing maintenance systems, processes, and practices. Our goal was to identify areas of lagging performance against industry benchmarks and uncover improvement opportunities.

The Outcome

Within six months of taking over operations, Isaac Plains had already achieved 100% nameplate production across the entire plant. Throughput more than doubled, from 1.7 Mt/y to an annualised rate of 3.5 Mt/y.

By implementing a revised labour model, as well as new supply agreements and maintenance regimes, the operation saw a 24% reduction in Operations and Maintenance services cost per tonne, with no negative impact on plant performance. A structured Work Management System improved long and short-term planning and scheduling, with shutdowns reduced from 17 to 10 per year, and more than 126 hours of additional operating time.

The site enjoyed a safety record of more than five years LTI free.