Modern Mining November 2022

24 hours awaiting signoff,” he says. “By increasing the stockpiling capacity, the DR400 can be

operated continuously with samples taken in real time.” He emphasises that

this solution has a dou ble benefit. Not only does it cut down on the standing time of stock piles awaiting approval, but also reduces the cost of double-handling large vol umes of material. Always safe Pilot Crushtec has always put safety at the forefront of its designs, and the DoppiaTrac DR400 is no exception. Its safety features are aligned with leading mining companies’ strict requirements, which allows the unit to go straight to work on any mining site. “Our design includes a standard safety pack com prising full guarding around all moving parts, access points, nip points and crushing points,” he says. “There is also an interlocking system, time delay start-up, pull cords and emergency stops to isolate the unit at the first sign of an emergency.” The mandatory sequential start-up sequence includes audible warnings before the start of each function, alerting all personnel that may be within an unsafe radius. Efficiency The operational efficiency of the DR400 is enhanced by its latest generation Volvo engine, with its EMS 2.3 engine management system. This deliv ers the lowest kW/tonne of any mobile double-roll crusher working in the coal sector. At a production rate of 400 tonnes per hour, depending on coal char acteristics, the 160 kW output converts to a ratio of 0.4 kW per tonne. “An important element of the low hourly cost is the impressive fuel consumption on this Volvo engine – as low as 17 litres per hour,” says Armitage. “Contributing to this low consumption is a hydraulic load sensing system and optimised crusher chamber design, which reduce the power needed to crush the coal.” With its state-of-the-art design and workshop facilities in Jet Park, Pilot Crushtec is also known for the outstanding quality of its service offering. Support and spares are always just a phone call away, he says, especially as the DR400 has been locally designed and manufactured. Over 20 of these units are currently supported across South Africa, with one having already exceeded 22 000 hours of operation. 

The double-roll crusher gives the DR400 the ability to generate a guaranteed product size without the need for post screening.

crushing contribute to fines. Nonetheless, it is not difficult to see why these machines do not need final screening to achieve the required coal specification. “Crushing efficiency is enhanced by feeding material into the crushing chamber at exactly the same speed as the drums are spinning,” he says. “This minimises attrition and friction, even at the high intended throughput rates of 300 to 400 tonnes per hour.” Making connections While the DR400’s large hopper allows it to be easily fed by loaders or excavators, it can also be interlocked as part of a crushing train with upstream and downstream communication. When crushing run-of-mine coal, for instance, the DR400 can be ‘connected’ to a Metso Outotec Lokotrack LT106 jaw crusher – Pilot Crushtec being the southern African distributor for Metso. “The connectivity between the two machines allows for an increased average production rate,” says Armitage. “This is achieved by instant com munication between the units to synchronise the feed-rate without needing manual operator interven tion; the system is essentially able to optimise itself.” The on-board hydraulic rock breaker on the Lokotrack LT106 speeds up the handling of oversize material and prevents downtime due to blockages. Another important value-add from Pilot Crushtec is its modular stacking system, which reduces rehan dling of coal and facilitates rapid sampling and testing. Stockpiles are created using a conveyor that slews on wheels, reducing the need for front-end loaders to continually double handle material. “The coal needs to the sampled and tested before it is loaded onto trucks for delivery to the end-customer – and stockpiles can stand for up to

“We have focused on giving the customer a solution that delivers value, with average production rates from 300 to 350 tonnes per hour and as high as 400 tonnes per hour,” says Abelho.

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