Construction World September 2022

From left: Louis Sterley, Rooikraal’s Works Manager, Themba Baloyi – Production Superintendent and Zielas du Preez, AfriSam’s Regional Manager - Gauteng and Western Cape Operations.

“The biggest challenge is sales demand. It is a cut throat market. Road projects are scarce and there are many competitors. In addition, we still have certain customers needing certain products. We are making a basket of products and cannot close taps to make a single product,” says Du Preez. “Because of the demand for 10 mm stone in the asphalt market, the tertiary plant used to run 24 hours a day, the secondary plant operated in two shifts of 9 hours each per day and the primary plant has always been a single shift. The current climate has forced us to play around and be flexible with what plant is operational and when. While we need to maintain our agreed stock levels, we cannot just run the plant. This is a challenge,” concludes Du Preez. 

Sterley. “This leads to cost savings as up to 120 000 tonnes of rock is blasted at the same time. The quarry also has wide benches which allow space for bigger blasts.” In addition Villa Liza, the closest community, is 2 km from the quarry. The only structures that are relatively close are 88 kVA Eskom transformer which is located about 260 m from the pit and the quarry’s office which is about 500 m from the area where blasting takes place. This potential risk has been mitigated by innovation in blast designs. “The better you blast the less you have to crush,” explains Sterley. “Our blasting achieves increased fragmentation which leads to easier rock removal, increased truck capacity and less wear and tear on crushing equipment,” says Sterley.

39 CONSTRUCTION WORLD SEPTEMBER 2022