Modern Quarrying Q3 2019

volume drivers. To meet the growing demand for these base materials, Afrimat has invested in a dedicated plant that particularly focuses on the production of these three materials. “We have experienced big demand on the G4 in particular, driven by road projects in our vicinity. To ensure stock availability, we invested in a separate process plant in March last year,” says Hierons. Production process To run a successful operation, there is a big focus on efficiency on site, all the way from drilling and blasting to load and haul and processing. From a blasting point of view, Hierons explains that blasts are kept fairly large, ensuring sufficient material on the ground per month. The quarry makes use of both conventional shocktube and new electronic blast- ing systems from BME. Hierons says electronic detonation is preferred for tricky areas. It offers accurate hole initiation for better blast fragmentation, which has a big effect on downstream functions such as load and haul and crushing. An electronic detonation also offers higher precision, improved blasting result owing to a wide range of delays, reduction of airblast/ground vibration and safe use in extraneous environments. When it comes to load and haul, the correct pairing of the loading tool and a hauler ensures efficient production. Two 35 t excavators, a Kobelco SKL 350 and a Hitachi 330L are used to load five Bell articulated haulers deployed to haul run of mine material from the pit to the processing plants over an 800 m distance. The dumpers include two Bell B30D units, one Bell B30E and a Bell B18E. Haul distances have been kept fairly short to reduce diesel burn and optimise cycle times for greater productivity. One of the key challenges on site is the fact that the mining area is still in the development stage. It takes a great effort to remove the overburden to expose the mineable blue rock. Overburden is sold as fill material, but its handling costs money and effort. “Ongoing plant modifications to produce cost-effectively offset the costs of overburden removal,” concludes Hierons. l

ON THE COVER

A Bell B30E is loaded by a Kobelco SKL 350 in the pit.

Kliprug achieved record sales in May this year.

A Bell B30D hauls run of mine material from the pit to the tipping point over an 800 m haul distance.

choice in the area. “The flexibility of our processing plant allows us to tailor make some of the products to the client’s specific needs. This is a key competitive edge for us,” says Cornelius. When it comes to some specialised products, Hierons makes special mention of the G2 to G4, which have since become some of the key

Base and sub-base material are currently the largest volume drivers, with civil contractors working in the area driving the uptake. This is followed by concrete stone products supplied to several readymix outlets. Speaking about the quarry’s competitive edge, Cornelius says the operation’s flexibility to make special products has made it the quarry of

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MODERN QUARRYING QUARTER 3 - 2019