Precisionscreen’s bucket wheel dewaterers, combined with the manufacturer’s fines recovery pod, create an efficient washing combo that benefits the environment.
For over 30 years, Brisbane-based manufacturer Precisionscreen has been serving the Australian quarry market with its range of mobile screening, washing, crushing and recycling equipment.
Notably, the company has been a key player in the industry for manufacturing low power sand and gravel washing equipment. Precisionscreen’s SRD180 bucket wheel dewaterer is an energy efficient product that can be powered directly from the hydraulic pack fitted to the screening plant, or alternatively use a diesel-hydraulic or electric-hydraulic power pack.
More recently, Precisionscreen has introduced a fines recovery pod, or FRP unit, which can be fitted at the end of the sand washing process to help dry (dewater) sand from a previous stage or recover sand from the wastewater before it returns to the pond.
Jonny McMurtry, chief operating officer of Precisionscreen, said the FRP unit allows for quicker dewatering, with a higher recovery rate of fine materials.
The machine also delivers a drier sand product, allowing the effluent water to be recycled more easily, with less harm for the environment.
“The SRD180 dewatere was one of the first machines we developed around 15 years ago,” McMurtry said.
“It’s designed to collect washed sand particles from a wet screening process and discharge it either to a stockpiler, or alternatively, it can feed the material to the FRP unit for further processing. The plant is designed to allow for excellent settlement time of the finer particles so that the discharge water is as clean as possible,” he explained.
The goal that Precisionscreen has pursued with its products’ designs has been to produce clean and dry sand for stockpiling, while allowing for maximum recycling of the water.
“In previous year, the dirty water that contained all the organic float material would be discharged directly into a pond for recycling. With the introduction of the FRP unit at the end of the sand washing process, the user can achieve multiple benefits. Firstly, you get drier sand for stockpiling. Also, you can recover the fine sand that’s present in the water before it’s discharged into the pond. This superfine sand can be stockpiled as a separate product. With cleaner water returning to the pond, re-use and recycling is much quicker,” he said.
The fine sand recovery in FRP is achieved with the help of an on-board 250-millimetre cyclone fed by the rubber lined pump that collects feed material from the base of the tank. The cyclone then discharges the fine sand onto the high frequency dewatering screen for draining. The newly recovered sand can then be deposited to the side of the unit via screw or out the front of the pod onto a stacker.
McMurtry said the process has allowed customers to recycle their drain water more quickly, while extending their ponds’ maintenance cycles.
“What we have found in some of the examples in the market is that customers [who used the FRP unit] were able to recycle and reuse their water about 30 per cent quicker, while utilising a lot of the material that would otherwise be returning to their ponds or settlement dams.”
Precisionscreen prides itself on being an Australian manufacturer, using only Australian sourced steel for its products, with all design and fabrications done locally.
Where this adds advantages, McMurtry said, was by allowing the company to take onboard feedback from its customers and implementing those into its designs, keeping the end-user in mind.
“We developed the FRP unit with the aim of helping customers reduce their cost for reclaiming super fine material and lowering their operational cost for recycling the drain water,” he said. “We had clients telling us they had a lot of material returning to their dams, who needed to recycle the water more quickly. Those ideas led to the development of the FRP unit.”
The SRD180 bucket wheel dewaterer has a larger-than-average adjustable 44.8 metre linear weir, which according to McMurtry, gives it its higher efficiency.
“Probably the biggest advantage of SRD180 would be the size of its weir. A smaller weir would let the sandy product return to the pond, whereas our focus was to try to minimise that.”
While Precisionscreen’s dewaterer and fines recovery pond have been designed to work in conjunction with each other, McMurtry said the FRP unit can also work independently with the other plants available in the market.
“Our products are all about precision, versatility and adaptability. From our factory in Queensland, we can support customers everywhere in Australia and beyond, working around our customers’ problems and offering solutions.”