The Premier coal mine is 13 kilometres south-east of the town of Collie, which is 200km south of Perth in WA. The mine produces about three million tonnes of coal per annum; it produced 2,799,000 tonnes per annum of thermal coal to December 31, 2010, and had produced 2,833,000tpa to September 30, 2011.
Produce from the Premier coal mine is mainly sold under long-term contract to its major customer; the state government-owned Verve Energy, for domestic power generation. Premier Coal, a subsidiary of Wesfarmers, also supplies the mineral sands processing industry in WA.
The Premier mine is a truck and shovel operation conducted in two pits of differing structure and stratigraphy – Pits one and four.
Pit one is currently mining four seams of the Premier Member series and will reach a maximum depth of nearly 75 metres. Plans for a ‘deeps’ option, which could extend the mine dept to more than 200m, were underway according to Premier Coal.
As the seams are relatively flat, the overburden and coal is mined in strips. The coal seams vary from between 1m and 2.5m thick. Overburden thickness increases to about 45m and has to be pre-stripped in layers.
The harder overburden is drilled and blasted where necessary, or where it will improve shovel productivity, before being removed.
Pit four extracts eight seams from the Muja Member, which occurs in a relatively steep synclinal structure. Here the overburden and thicker interburdens have to be benched. The coal seams vary in thickness from between 1m and 12m. This pit will eventually join up with the adjacent Muja mine and will reach a maximum depth of nearly 200m.
The coal is hauled to the coal handling plant by truck, and processing involves crushing and sizing prior to blending on stockpiles. The coal plant at Premier has a Malco stacker/reclaimer system, which produces an extremely consistent product by virtue of stacking in one direction and reclaiming at right angles. The coal product is delivered to either of the two nearby coal-fired power stations, Muja or Collie, via overland conveyor systems. Deliveries to other customers occur by rail or truck using the train load-out system.
Operating. In September 2011 Wesfarmers announced it had agreed to sell its Premier coal business to Yanzhou Coal Mining Company for $296.8 million. The sale is subject to a number of conditions precedent including approvals from the Australian Foreign Investment Review Board and Chinese government authorities, which would be sought in the following months.