Two years ago Komatsu Southern Africa made its first sale of a 206 t Komatsu WA1200-3
‘Mountain Mover’ wheel loader, when Kumba Resources purchased one for the Sishen open-pit iron ore mine in the Northern Cape as a replacement and upgrade on a unit in its
existing fleet of 190-tonners.
So pleased has the mine been with the performance and high productivity of the Komatsu unit that it has purchased a second, which it took delivery of at the end of August 2006 – again replacing one of its old 190 t loaders.
The ‘Mountain Mover’ has also found favour with leading phosphate producer Foskor for its open-pit mine at Phalaborwa in Limpopo Province. The company is due to take delivery of its first unit soon, as a replacement for two smaller wheel loaders.
The WA1200-3 loaders at Sishen are used to load ore in the pit into Komatsu 730E haul trucks. Sishen has the largest fleet of 730Es in Africa, with a total of 40 units, the longest serving of which has recorded over 67,000 operating hours, with an average availability of 92%.
The mine’s first WA1200-3 loader has clocked up over 13,000 operating hours to date, with availability averaging 93%. “It is a lot more powerful than the machine it replaced and, as expected, productivity has been improved greatly as a result,” commented Arrie Theron, Sishen’s senior planning and development engineer on mining equipment.
He said that the WA1200-3s, which are equipped with smaller-than-standard 13 cu m buckets to suit the high specific gravity of the ore, are ideally matched with the 730E trucks, loading each in four to five passes.
Theron added: “In the early stages, after putting the first machine into operation, we had teething problems with the tyres, due to our high ambient temperatures and longer-than-usual tramming conditions.
“I must commend Komatsu for the way in which they attended to and solved this problem, most especially for the exceptional efforts of Tom Suketomo, senior adviser mining operations (now retired) in Japan, who was mainly responsible for organising the development by Bridgestone – in conjunction with Komatsu – of a tyre with a new composition, which was supplied last year and has given excellent performance,” Theron added.
He said that Sishen enjoys a good relationship with Komatsu SA, and the service support the company provides from a depot on site is prompt and efficient.
In addition to the two WA1200-3 loaders and the 730E truck fleet, other Komatsu equipment owned and operated by Sishen comprises two 540 t H485S face shovels, a 300 t H285S face shovel, a 110 t PC1250SP-7 hydraulic excavator, two 104 t PC1100SP-6 hydraulic excavators and a 41 t WD600-1 wheel dozer.
The WA1200-3 wheel loader scheduled to go into operation at Foskor’s mine in October this year will replace two 100 t class wheel loaders currently in use – one being a Komatsu WA800-3 unit – to load the mine’s 12-strong fleet of Komatsu 730E haul trucks in the pit.
Mine manager Derek Esterhuysen said it was selected over other similar class machines of other brands because it was found to have the lowest predicted total cost of ownership.
Until recently the smaller loaders were used mainly to load four 100 t capacity haul trucks that have been replaced by four 730Es. Foskor’s WA1200-3 loader will be equipped with a fit-for-purpose 17 cu m bucket designed to load each 730E unit in an optimum five passes.
“The loaders are also used as temporary standby primary mining tools in place of rope shovels when the shovels have to be moved out for blasting operations. They have the advantage of flexibility, as they can operate in confined areas. Until recently we used other rope shovels as standby units, but using loaders is a much more cost-effective and efficient method,” Esterhuysen explained.
“The WA1200-3 loader – besides being the right tool to load the 730E trucks, thereby enabling us to optimise use of the whole fleet – is well suited for the standby digging function.”
Among Foskor’s other Komatsu equipment is a 490 t PC5500 hydraulic face shovel that the mine uses exclusively for loading a large stockpile of phosphate ore to supplement production out of the pit. This machine has performed over 22,000 operating hours to date, with average availability in excess of 95%.
The longest serving of the 730E haul trucks has recorded more than 50,000 hours, with availability averaging above 90%.
Sumber : Mining Review Africa