Capital Equipment News September 2015

MINING

All trucks are fitted with an eight metre boom conveyor (170 degrees). Karel Steyn, technical manager at Cobra Petro Projects.

A stemming truck under construction at Cobra Petro Project’s facility in Johannesburg.

One of the three conveyor belts present on all trucks.

manager at Cobra Petro Projects.

the dash allows the operator to keep a close eye on the amount of aggregate delivered or that remaining in the hopper, and another notes the vehicle’s gross vehicle mass.

What is stemming? Stemming is a key element in the ‘drill and blast’ mining technique. In stemming, material, such as fine gravel that is called aggregate, is placed on top of explosives in drill holes. When the explosives are detonated, the stemming locks the expanding gases and keeps the forces in the borehole until rock begins to break. A stemming truck’s duties are to fill blast holes on a mine site into which the explosive charges have already been inserted. Typically these are located at five- metre intervals in the area to be broken up. A 16 m 3 load can fill up to 60 holes, and stemming truck can easily deliver 500 kg in 15 seconds, allowing excellent productivity on site. Source: Scania

“Precise measurements of aggregate can be inserted through the truck’s load-cell sys- tem and this means no wasted material, no wasted time and the provision of the exact amount of resistance for the blast.” Other benefits of using the stemming truck include operational safety (one truck and operator) versus several smaller vehicles; being able to access hard-to-reach blast areas with an 8 m boom conveyor (170 de- grees) and significantly decreasing the time between charge and blast to an almost neg- ligible period. Aggregate flow control and rear boom ma- noeuvring can be carried out through a joy- stick mounted in the cab or via a wireless remote control from outside the vehicle. A neatly integrated control screen fitted into

The trucks are available in two configura- tions:

• 13 m 3 hopper • 16 m 3 hopper

Elements of the unit as well as the interior of the cab can be suited to exact client re- quirements. As the trucks are manufactured locally, clients benefit from local support teams and spare part availability. Scania and Cobra Petro Projects are proving that the incorporation of such game-chang- ing stemming truck technology guarantees increased blasting efficiencies across the opencast mining sector in southern Africa which can in turn increase production – ulti-

mately resulting in higher profit margins in a repressed commodity down cycle. b

Written by Richard Jansen van Vuuren Photographs: Jade Photography and Eventco Strategic Marketers: Scania and Richard Jansen van Vuuren

CAPITAL EQUIPMENT NEWS SEPTEMBER 2015 31