Premier

Premier Coal, in Western Australia, began its mining operations near Collie in the south west of the state in 1950 and up until 2013, had produced 90 million tonnes of black coal. Over the years it has operated as both an underground mine as well as an open cut operation. Today it is an open cut operation only with large reserves promising it a long future.

Clearing Vegetation is a Major Task at the Premier Mine Site

Mining coal at the Premier open cut begins with the necessity to clear vegetation and overburden before getting down to the coal deposits. This is a big operation in itself before coal mining proper can proceed, particularly at the Collie mine site as it is surrounded by forest. Clearing vegetation means the clearing any commercial forest products. This is carried out by the Western Australia Department of Conversation and Land Management. The firewood left behind after commercial logging has ceased is removed by Premier mining personnel after which the remnants are pushed into windrows by bulldozers for burning. The next stage involves removing the topsoil, a most important operation, as it will be required again at a later date when the mining of coal in that particular area expires and rehabilitation is undertaken. The unique timber, Jarrah, is common in the Collie area and much care has to be taken to make certain no die back occurs when colonies of this particular timber are disturbed.

Two Pits Make up the Premier Coal Mining Operation

Mining of coal at the Premier open cut mine is carried out in the traditional shovel and truck type operation. This takes place in two distinctly differently structured pits, Pit One and Pit Four:

Pit 1 - This pit is presently mining coal in four seams that reach a depth of 75 metres although tests have proved coal at depths of more than 200 metres are in existence. Because the seams are inclined to be flat the coal body is mined in strips, the thickness ranging from one to two and a half meters. The covering overburden averages 45 metres and the inter-burden between coal seams ranges from two to 18 metres. The overburden and inter- burden consists of sandstone, siltstone and shale. The harder rocks are blasted when required to improve shovel operation.

Pit 4 ñ There are eight seams of coal at pit 4. These can be quite steep at times causing the overburden and inter-burden structures having to be benched. The thickness of the seams of coal in Pit 4 vary from one to 12 metres. This pit will eventually join up with the Muja underground operation where the coal is found at a depth of close to 200 metres.

Both pits use electric shovels to excavate overburden and inter-burden and to load it into 240 tonne diesel electric haulage trucks, The amount of overburden and inter-burden removed on a daily basis would equal 40 Olympic sized swimming pools.

Before mining of the coal deposit can begin the coal seam has to be cleaned with bulldozers and graders. Mining then takes place with the use of hydraulic excavators. Thicker seams sometimes require blasting before being mined to increase productivity levels. Thinner seams, however, can usually be ripped, therefore avoiding the need to blast. In many cases the coal can be extracted by free digging of the excavators.

The same truck fleet that removes the overburden is used to haul the coal out of the pit to be processed, a procedure that entails crushing and sizing before being stockpiled. The coal is then delivered to either the Muja or Collie power stations by conveyor. Other deliveries are transported by either rail or road depending on their destination.

Premier Mine Coal has Many Uses

Eighty percent of the coal produced at the Premier mine is purchased by Verve Energy to power their generators at their Muja,Collie, Kwinana and Worsley power stations. Alumina Pty Ltd purchase about 13 percent for their own on site power needs. Iluka use it to fire their kilns in the production of rutile from Western Australia beach sand (ilmenite).