CDE customer Cluster Holdings in West Rand, South Africa, had given up on ever recovering fines its sand screw classifier system had discharged into ponds.
However, with the introduction of the CDE EvoWash 71 sand washing plant to its operations, Cluster Holdings now produces high quality plaster sand from waste pond material. With CDE technology, fines are fully recovered and turned into profit and a very competitive return on investment.
Cluster Holdings is a family business like no other. Not only does the company wash materials for the construction industry, but it also runs a farming business. Cattle graze and crops grow in fields adjacent to the family’s quarry located half way between Carletonville and Randfontein.
Rich in decomposed granite, the farm and its surroundings presented an ideal terrain to develop a materials processing business to supply local construction companies with washed plaster sand. At the start of its washing operations in 1986, the company opted for sand screw classifiers to wash the granite, which is a cheap and popular choice in South Africa. However, this option creates a lot of waste to ponds and a loss of potential profits. The subsequent switch to a cyclone tower resulted from identifying the potential in the plaster sand market in the area but did not achieve the desired results in quality. This then led to wet stockpiles.
Wayne Warren, Business Development Manager for sub-Saharan Africa at CDE, noticed Cluster Holdings’ operations while on the road to visit a client and stopped by. “Being in a reasonably remote area, the road past Cluster Holdings’ mining area allows you to get an overview of their operations. I could see where they might have issues and knew that CDE had solutions that could up most current washing plants. I stopped in and introduced myself,” says Warren.
“Little did I realise that this site had such extreme potential in waste. In effect, unknown to the customer, plaster sand was lying in abundance, hidden at the bottom of ponds. Using adapted CDE technology this could be recovered and processed into a valuable product,” adds Warren.
“Kobus Jv Rensburg of Cluster Holdings provided samples for tests. It turned out that the waste sand had one of the best plaster sand grading I had come across in some time and it became Cluster Holdings’ priority to recover it.”
With CDE, which has a solid footprint in South Africa, the customer had the opportunity to visit a few sites showcasing the CDE EvoWash in action. Having witnessed the efficiency of the EvoWash that produced a sand that is dry enough to be handled and loaded as it came off the stockpile conveyor, Cluster Holdings opted for CDE technology as the perfect solution to its problem.
An EvoWash 71 materials washing plant was commissioned and installed to process the raw decomposed granite feed. The EvoWash removes the -75µ from the sand slurry feed and de-waters it to produce up to 50 t per hour within specification for plaster sand that will be used by the local construction sector to plaster buildings.
“After years of trial and error, we are delighted with our choice. We had two plants that were not efficient enough for our purposes and replacing them with a single plant and process was beneficial in terms of footprint, value for money and efficiency,” says Kobus Jv Rensburg.
“The CDE EvoWash is a very neat plant that we are exceptionally happy with. It is compact, efficient and economical. But crucially, it has allowed us to recover a high quality plaster sand that had been lying unnoticed in ponds and make it a very profitable product,” he adds.
“I was going to say – Who knew? But then again, CDE knew. It only took a visit from Wayne and some testing at the CDE labs to make us realise we were literally sitting on a high value quantity of quality plaster sand. All we needed to turn it into a profitable material was the right technology. The CDE EvoWash was the answer.”