Quarry Southern Africa March 2019 | Page 21

WINNING this plant no longer falls under the quarry manager’s responsibility, other than to ensure it has sufficient material to keep it constantly busy. If there is no new material from the quarry, the staff and saws stand idle to the detriment of the quarry’s production targets. It is a just-in-time production methodology, with each day’s material processed in full by the plant with no stockpile maintained, he explains. The only completed blocks on the site are those awaiting loading to Richard’s Bay for export. The substantial processing plant cuts blocks to size and otherwise prepares it for transport and sale. Equipment Apart from the equipment for drilling and blasting, the additional equipment used in the pit is seven front-end loaders (988Fs Komatsu) and one Terex Bell dumper on each. Every machine has a number of quick- hitch attachments, including a 9m-long boom or rake, a fork, and a bucket, used respectively for shifting blocks too high to reach as well as taking away blocks and waste. “This is very rapidly done — it’s only two levers.” www.quarryonline.co.za  “Springbok’s dimension stone quality is among the highest in Rustenburg – a quality renowned throughout the world.” Gerard Smit, Springbok Quarry acting manager The pit averages approximately 20 000 tonnes gross of material a month for a net 4 000–5 000 tonnes of product a month. “To load a block takes about five minutes, and it’s equally quick to cover the three to four kilometres to the processing plant. Where most time is lost is in offloading the blocks at the processing plant, where currently only one of the two cranes is functional — and this can take as much as three hours,” Smit says. There is a close relationship between the quarry and the plant, and when a bottleneck is developing with no blocks readily available to cut — a frequent occurrence when working at full capacity — the quarry will send a loader from the pit to the plant to speed up offloading. “This situation only occurs because the second crane is undergoing vital maintenance, and it will be relieved in the future,” says Smit. Fixing the crane requires Chinese mechanics, which in turn requires work permits — one of the quarry’s challenges. The challenges The biggest challenges faced by the quarry match its biggest expenses, which are 40% labour costs, 30% diesel, and 10–15% maintenance of equipment. Anything that can hamper labour and production is a risk. “Every day is different. The daily challenges consist of the variables and the negative characteristics in the rock itself. The defects in the rock are the single biggest issue for us. One day you will be working on a bench which looks the same as the one adjacent and you are ready for a day’s production, but we can never predict what the rock is actually like beforehand because we don’t know what is in the back. QUARRY SA | MARCH/APRIL 2019_19