Modern Quarrying Q3 2018

The three ADTs haul material from the pit to the processing plant over a distance of 1,5 km.

communication are very open. I can speak directly to Carl, the director at Dezzi, for any urgent issues. That makes it easy for us because there is no corporate protocol, which is often frustrating due to the delayed nature of the decisions,” he says. Peak production Due to the growth of its business, Rossmin entered full production a year ago, a year after start of production. The production process starts in the pit where a 35 t Komatsu 350 excavator loads the three Dezzi ADTs. Another Komatsu 270 excavator is being used for quarry development where a new pit, as part of the expansion programme, is being developed. The three ADTs then haul material from the pit to the processing plant over a 1,5 km distance. The taxing mountainous terrain is one of the chief operational challenges on site. “The major challenge is that we haul uphill when fully laden. Of that 1,5 km hauling cycle, half of it is uphill and laden. The haul is a 5,74-degree slope, which makes it a difficult application,” says Shozi. However, the “Africa tough” Dezzi ADTs are making light work of the 10% hauling grade, and Shozi is highly impressed by the performance to date. “We are very happy with the machines. The uptime, sitting at 98% availability,

4 000 hours and the other two are in the 2 000-3 000 hour region,” he explains, adding that support from Dezzi has also been great, and has been a major driver of uptime on site. The ADTs are consuming about 16,7 ℓ of fuel per hour, which is very impressive, bearing in mind the steep hauling route. The run of mine material from the pit comes at 600 mm size and goes through an Osborn Engineering primary crusher, which has a production capacity of 150 tonnes per hour. It is milled down into three grades, from 8 mm-30 mm; 30 mm-10 mm and 10 mm-dust. From here, product goes through a sorter plant, supplied by IMS Engineering, where it is sorted for parameters such as colour and shape. It then goes through the sand crusher where it is crushed down to micron sizes, including 45 micron (being the finest), 250 micron and 1 200 micron sizes. The FELs are deployed to work on stockpiles. The setup of the operational process requires an FEL to load material stockpiled by the crusher into the sorter. The other FEL loads material from the sorter into the sand plant. The units are also deployed to load customer trucks at stockpiles. “We are very happy with the performance of the Dezzi FELs to date. From a fuel consumption point of view, they are very efficient, using about 13,7 ℓ of fuel per hour,” concludes Shozi. l

feel of the product.” Gutzeit says Dezzi made a decision to pull some new and used equipment to hire it out to Rossmin. “As an OEM, we generally don’t do hire, but Rossmin was a strategic customer for us, and they are right at our doorstep, and we made sure we would meet their needs to sow the seeds for a long-term relationship,” he says. The vicinity of the Dezzi factory is already paying dividends for Rossmin. From a parts supply and service perspective, response times are very quick, leading to a 98% equipment availability to date. From an equipment customisation point of view, the close proximity of the factory means that any alterations to the equipment as per Rossmin’s operational needs can be executed timeously. For example, with its 25 t ADT, Rossmin realised that it needed an adjustment to the bin in terms of its length to allow for an optimum throw of material when tipping. The initial bin was a bit short, and as a result the truck had to run to the edge of the beam for it to be able to tip effectively, which also presented the possible danger of tipping over. “We extended the overhang of the bin from the back of the rear wheel to the end of the overhang for it to be able to throw material a bit further,” says Gutzeit. Meanwhile, Shozi is very pleased with the open channels of communication between the two companies. “The channels of

has been fantastic. One of the machines has already clocked

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QUARTER 3 - 2018 MODERN QUARRYING