Stemming is a key element in the “drill and blast” mining phase. In stemming, material 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.
The stemming trucks are designed to efficiently stem the holes on a blast pattern. That is to fill blast holes on a mine site into which the liquid mixture of ammonium nitrate and fuel oil explosive charges have already been inserted. Stemming using the Ausroad Stemming trucks is revolutionizing the way stemming has being done in the past- the application can contribute in making the blasting procedures faster and more efficient, explains Lloyd Darby, Managing Director for Cobra Petro Projects.
Ausroad stemming trucks are designed to operate in demanding environments encountered during normal mining operations. Design parameters include all necessary safety control features, as well as ease of operation, maintenance and reliability.
Different companies are manufacturing stemming trucks with different capabilities and features, and Scania trucks are manufactured with extra duty chassis homologated in this market which allows for large volume stemming units. The trucks have the capability to deliver 14-16 cubic meters of crush aggregate.
Additional features of some of these trucks include water spray system to control dust, a metering system that can determine how much stemming to put in the hole on a meter basis, zero waste of aggregate, single operator function via joystick control from the cab, custom length placing conveyor to reach either side of truck for stemming , etc.
In addition, benefits for using stemming trucks include operational safety (one truck and operator) versus several smaller vehicles; ability to access hard- to-reach blast areas with an 5 m boom conveyor (270 degrees); and significantly decreasing the time between charge and blast to an almost negligible period.
Scania South Africa and Cobra Petro Projects recently partnered to produce stemming unit that increases blasting efficiencies across the open-cast mining sector in Sothern Africa which in turn can increase production- especially at a time when mining sector is facing a number of challenges including high production costs, commodities prices, labour unrest etc.
Scania’s new stemming truck technology will make it easy to ensure that the correct amount of precisely sized aggregate is delivered into the blast in an efficient manner- one unit with one operator can stem 300 holes in a shift, adds Lloyd Darby.
The trucks are available in two configurations, that is a 13 m3 hopper or a 16m3 hopper, and the elements of the unit as well as the interior of the cab can be customized to meet client requirements. Since the trucks are local manufactured, clients are guaranteed of local support as well as readily available spare parts.