SAND PROCESSING
QUARRIES USE WATER TOO:
EFFICIENT WATER MANAGEMENT SOLUTIONS Water and its usage is as vital as the aggregates quarries produce – particularly in practices such as sand processing. However, equipment can now be optimised to close the loop of water processing without impacting on productivity and profits and indeed boosting product solutions and innovations.
F
or an outsider, water management might not be the first thing that comes to mind when thinking about quarries. However, water availability and wastewater management have been a strong focus for quarrying and mining operators since the early 2000s when the states introduced mandatory licences for previously unlicensed water use for quarries. Restrictions on water extraction from the natural environment have made the recycling of process water a must for quarrying operators. Operators must now compete for licences in fully utilised systems or in rural areas where there are no new water licences available for industry to expand, or where the total licensed extraction is actually being reduced. The management of process water, reclaim systems, dust suppression and pit dewatering is essential to the success of a sand and aggregates project. By managing these processes efficiently, quarry sites can process more product faster, while lowering their water bill and eliminating the need for double handling. Most quarries use water in the washing and processing of their products. For example, sand washing, a necessary step for producing high quality sand, utilises both recycled and clear water. Once the sand has been processed, wastewater containing product fines and additional wastewater run-off from the stockpiles make their way to storage or tailings dams. All these water sources need to be managed effectively for 30
Quarry April 2020
Weir Minerals’ equipment can manage water more efficiently to provide a drier end product.
the quarry to keep their operational costs under control.
FROM A TO B “Maintaining the water level balance on site is very important to everyone,” Darren Van der Westhuizen, Weir Minerals’ territory manager for dewatering, explained. “No matter what you’re processing, you’ll always need to move water from point A to point B.” The new decade has brought to light new problems for fluid transport, from the introduction of water restrictions on urban water supplies to climate change affecting the supplies of non-potable groundwater (rainwater, groundwater and stormwater).
By transporting and making use of water already available on-site, quarries can reduce the cost of water licences and make their investment go further. “Increased awareness of the positive outcomes achievable with efficient water management provides us the opportunity to partner with customers to explore and develop new and safer water management systems,” van der Westhuizen said. “We target the challenges the quarries are facing with regards to pumping water around the site with the focus to champion and provide the most optimum solution for each specific and unique application.” Pumps designed to handle increased
