Quarry Southern Africa July 2019 | Page 18

WINNING END OF LIFE By Eamonn Ryan | All photos by Eamonn Ryan Corobrik owns a 50-year old clay quarry in Olifantsfontein, Midrand, that predates the existing adjacent 30-year-old brick-making kiln. With just two years’ mining left, rehabilitation of the site is top of mind. T his quarry has just two seasons of mining left at a rate of 1 000m3/day in its mining season of three months of the year ‒ the dry winter months, as the rainy season makes work slippery. Actual mining activity is outsourced to a mining specialist company. The contractor owns its own equipment. Corobrik factory and quarry manager Heinrich von Wielligh explains that the mining company simply rotates its equipment on site according to evolving needs. On the day of the visit by Quarry Southern Africa, much of the equipment appeared to be Caterpillar, though it is apparently generally a mix. Von Wielligh explains that while there is no particular preference for brand, the specifications of the type of equipment makes a substantial difference to mining productivity. Too small a bucket slows down the turnaround time of material per hour, costing more time and fuel – the quarry’s major expense. “There’s a fine balance between machine size, bucket size and travelling time.” He says the mining team typically consists of one or two 40t to 50t excavators, between three and eight This quarry has just two seasons of mining left at a rate of 1 000m3/day in its mining season of three months of the year – the dry winter months. 16_QUARRY SA| JULY/AUGUST 2019 www.quarryonline.co.za