A plant train comprising a mobile jaw crusher and a scalping screen from Kleemann processes material for the rehabilitation of the infrastructure at an Indonesian lignite mine.

The major challenges in the extraction of the material are its scattered locations on the mining site and the frequent need for blasting, revealed Kleemann. As such, the ability to easily and flexibly relocate the machines was a crucial factor in the considerations of the mine operator.

The Mobicat MC 120 PRO is used as a primary crusher, while the downstream Mobiscreen MSS 802 EVO mobile scalping screen is employed for the screening of the crushed material. According to Kleemann, initial results show that these mobile plants enable trouble-free processing of the andesite rock. At the same time, it soon became clear that the machines would have no problems at all with the special demands of processing of this volcanic rock.

Both machines are also equipped with technology that allows operation from an external electric power supply – a future-proof and sustainable option. The infrastructure for this will be realised in the near future, said Kleemann. Until then, the operator will continue to benefit from the low fuel consumption of the two machines.

“The option for operating the machines electrically takes us a big step forward on the way to the achievement of our sustainability goals. Nevertheless, the fuel consumption is very low when we run the machines on diesel,” said Aditya Maulana Bainal, sales engineer at PT Bukit Asam Tbk, the mine operator.

Efficient and flexible plants

Many of the features of the jaw crusher are designed to achieve an efficient workflow. The hopper extension, for instance, makes it possible to take on larger quantities of material and increases the hopper capacity from 10 to 13 cu m. The hopper walls can be folded out by remote control from the ground. The feed material is screened effectively by the independently vibrating double-deck prescreen. This enables fines to be removed via the side discharge conveyor before they reach the crushing chamber.

The conveyor unit is also hydraulically foldable, and can remain on the machine during transportation. The rock chisel, a further equipment option for the jaw crusher, can break up larger boulders in the feed material at the machine before it is passed to the crusher. This enables easy removal of blockages caused by material bridging during the passage of material from the prescreen to the crusher. Another advantage is that the rock chisel can remain on the machine during transportation.

For this project, a service technician from Kleemann spent two weeks at the site setting up the machines and training the local personnel in readiness for the start of production. The effort also included a series of theoretical training sessions, practical application training and trials.