Joy Mining Machinery, based at Moss Vale in the southern coalfields, is enjoying a period of good sales of longwall and coal development equipment, according to sales support manager Jim Wilson.
Apart from the contract to refurbish and supply new longwall chocks for BHP Billiton’s Dendrobium mine in the Illawarra, it is also supplying a new longwall for the Westcliff redevelopment. It also recently completed the longwall rebuild for Xstrata Coal’s United colliery in the Hunter Valley.
On the development side of the business, at one stage it won 11 out of 11 orders for continuous miners in Australia.
Three new Joy 7LS shearers are also on order, for Dendrobium, Newstan and Tahmoor.
The Tahmoor machine has already left the US factory and will go on show at Joy’s stand at the September AIMEX mining exhibition in Sydney, together with one or more of the Westcliff chocks.
The Newstan machine is advanced in manufacture and will be completed around the end of September and will be followed about one month later by the Dendrobium shearer.
The company’s continuous miner order book has seen a hive of activity at the Moss Vale plant, where the units are made with a high Australian content.
During Australian Mining’s visit, two machines were under construction for Anglo Coal’s new Grasstree mine in the Bowen Basin in Queensland. These units are designated Joy 12ED-5.2B, signifying use for entry drives with a wide head and B height range.
Other recent continuous miner orders were a Joy 12CM30 for Roche Mining, and units for North Goonyella, Tahmoor and two for Walter Constructions (the company at present developing BHP Billiton’s Dendrobium mine but also expanding its presence in the contract mining industry).
Rebuilds
There are also a number of rebuilds underway, for mines like Centennial Coal’s Cooranbong where the continuous miner will be transferred on completion to the Clarence colliery near Lithgow.
Wilson says the significance of recent continuous miner orders is the ability to change the unit’s configuration depending on mine conditions.
The Joy 12CM30 has an east-west shovel arrangement for coal gathering compared with the traditional 12CM12 centrifugal loading arm shovel, or rotating arms.
The current design of continuous miners allows the two methods to be interchangeable on the same machine, following redesign of the mainframe, cutter boom and shovels.
Eleven of these interchangeable units are now in operation and have proved particularly popular with contractors who can switch between the two modes of operation in a weekend.
Future development in Joy continuous miners is likely to come in high voltage machines for place changing style mining.
In the US, a number of these 2300V (3300V in Australia) continuous miners (compared with the conventional 1000V units) are in operation.
Joy is presently quoting in Australia for several machines for bord and pillar place change mining or gateroad development, particularly in new mines where high voltage reticulation is planned.
Although more expensive than a conventional miner, the Joy 12CM27 and 14CM27 high voltage machines have a robust design, and in the US miners have consistently been able to mine an extra 1Mt of coal before a rebuild is required.
The 12CM27 fits into the same entry size as the Joy 12CM12, but has a loading rate of 17-32t a minute. Standard cutting width is 3.505m and the maximum cutting height is 3765mm.
The 14CM27 incorporates variable speed ac traction drive and Joy Network Architecture II electronics for optimum cycle productivity. Maximum cutting height is 3055m.
The real opportunity for these high voltage continuous miners comes when they are put into operation coupled with a flexible conveyor train.
Conveyor train
The Joy 4FCT01 conveyor train, for example, can simultaneously follow a continuous miner’s each move while providing a continuous flow of coal onto the panel belt.
The 4FCT01 can be operated by one person via radio remote control. It comprises a mobile feeder breaker coupled to a mobile concertina conveyor system that can extend up to 128m as the continuous miner advances, tramming at up to 0.38m a second.
With a belt width of 1067mm and a speed of 3.5m/s, it can convey up to 27.2m3 a minute. Machine turning radius is 9.4m at centreline, enabling it to operate effectively in bord and pillar operations.
Joy Mining over recent years has expanded its presence nationally, not least through the acquisition of Australian Longwall and Cram (now known as Joy Bolting Solutions) at Wollongong.
Its geographical presence has been strengthened by expansion of its Parkhurst plant near Rockhampton in Queensland to service the Bowen Basin coalfields.
More recently, it has opened a factory at Hexham in Newcastle for rebuilds.
At Wollongong, the Joy Bolting Solutions plant is now also handling all hydraulics and electronics manufacture and servicing.