Published in the September 2014 Australia’s Mining Monthly

Engineering and mining consultancy GHD has helped Anglo American carry out a challenging plant upgrade.

The upgrade included achieving maintenance, safety and adhering to capital cost objectives.

GHD was contracted to undertake the design and documentation for the upgrade of the coal handling and preparation plant tertiary sizing station and associated equipment at Anglo American’s Drayton mine, as well as supporting existing operations and the proposed Drayton South expansion.

The open cut, thermal coal mine is situated between the towns of Muswellbrook and Singleton in New South Wales’ upper Hunter Valley.

GHD’s objective for the project was to modify the existing tertiary sizing station to deliver a process at a peak rate of 2,000 tonnes per hour with a nominal rate of 1,600tph.

It also had to extend the service life of the facility for the next 25 years.

The upgrade had to accommodate foreseeable coal from the Drayton South operation, which indicated coal deposits with quantities of clay.

Handling these products was seen as the greatest hurdle for the project and the performance of the installation.

To address these issues, GHD developed a three-dimensional model of the existing plant and new design elements.

“This is not new, but it was one of the first projects where all drawings and project documentation were produced directly from the model, rather than the other way around,” GHD project manager Mal Peattie said.

GHD completed the mechanical, structural and electrical design and documentation for the project.

The 3D model was used to coordinate and accurately plan the demolition and construction staging to minimise the impacts on the existing operations.

Furthermore, Peattie said the model helped project stakeholders understand the scope and nature of the project.

“It made it easier to identify and address risks at the design stage, generating tangible safety benefits throughout the project lifecycle – from demolition, construction operation and maintenance,” he said.

“Since the drawings were based on the model, there were fewer inaccuracies, providing a greater degree of certainty on cost outcomes and an ability to refine the design to manage costs.

“The Drayton project was especially pleasing in that we were able to build on that modelling experience and incorporate our Building Information Modelling skills from our buildings team. We developed a fully functional and representative model of this project.

“This saved the client time and money in the design phase by making review sessions more effective and facilitating operator input into the final functionality of the system.”

GHD also assisted Anglo American in reviewing the design and projected mine production schedules so it could select the right sizing station equipment.

Peattie said retrofitting the new sizing station to the existing plant presented a number of challenges.

The sizing station plant had to be situated within the existing building due to constructability, operational and safety requirements.

This included dedicated equipment roll-out platforms for maintenance with either mobile or fixed crane access to the equipment.

The Preparation Plant was first commissioned in 1983 and has since undergone several upgrades.

Drayton began operating in 1983 and currently produces around five million tonnes of thermal coal each year for export and domestic markets.

The mine employs around 500 people.