In-pit first for china
08 May 2008
Two Lokotrack LT140 mobile crushing plants, each linked to Nordberg LL12 mobile conveyors, are producing 2000 tonnes of aggregate per hour at the Dafaping Quarry, for the nearby Longtan hydroelectric dam in China's Guangxi Province. This is thought to be the first in-pit crushing application in Mainland China.
One of the key features of the site is that it is extremely narrow, which meant the traditional approach of using haulers to feed a fixed crusher was out of the question.
An ‘in-pit’system using a mobile crusher that can be moved close to the face when it is needed for primary crushing, and moved out of the way during blasting was therefore selected.
As well as being suited to the layout of this particular site, the fact that the in-pit system does not require a haulage fleet has some inherent advantages. Running costs for fuel and tyres are much lower. Fewer operators are needed, and fewer exhaust emissions are produced on site.
In addition to the Lokotrack LT and LL units, the operation at Dafaping Quarry includes four Nordberg NP1520 impact crushers for the secondary crushing and two Nordberg NP1315 crushers for the tertiary stage. All products are transferred from Dafaping to the readymix concrete plant, alongside the dam site by a 4.5 km long conveyor, via a tunnel excavated through the mountain.
“We have been very pleased with the ‘in-pit’ system's performance. Everything is working as planned,” said Qi Tao, deputy general manager of the Gezhouba Group and Guangxi Hydropower Construction Bureau Joint Venture, in charge of crushing operations.
He continued, “We are very excited about this project. It is another milestone in modernising China and we are proud to have the opportunity of working on it.”
Longtan (Dragon's Beach) is China's second largest dam project, behind the Three Gorges project, and the largest to start construction this century, with work starting in 2000. Longtan, in the Province of Guangxi in Southern China, will control the flow of the Hongshui (Red Water) River.
When completed, the dam will have a height of 400 m and a dam crest width of 735 m. It will have a total installed capacity of 5400 MW and form part of the ‘West-to-East’transmission programme. Enquiries 330
