As featured in Quarry Magazine.
Kingscliff Sands, in northern New South Wales, has endured a lot for a start-up business – a global pandemic, an uncertain economy and adverse weather. Its choice of wet processing plant has been a boost in such trying times.
The booming coastal town of Kingscliff is less than 10 minutes’ drive south of Gold Coast Airport, in the New South Wales Northern Rivers region. Along with the nearby villages of Chinderah and Cudgen, Kingscliff’s major industry is tourism and its businesses cater to retail, accommodation, food, and beach and water sports.
For Brad Holloway, the quarry manager of start-up extractive business Kingscliff Sands, it is both an idyllic locale and a uniquely positioned one for his burgeoning business.
“We’re on the doorstep of the Gold Coast,” Holloway told Quarry. “It’s a great spot. We’ve had orders from Brisbane down to Lismore. It’s a great place to be, from the bottom of the Gold Coast to the top end of the Northern Rivers.”
Kingscliff Sands has been operating for 14 months, so Holloway, who is just 24, and the business are still very much newcomers to the quarrying industry. A few years ago he was running cattle on the very land that is now home to his sand quarry operation.
“We run cattle on the land, and that’s how we got to know the owners of the resource,” Holloway explained. “They offered us the opportunity to run a sand quarry, and after three years of research and finding out what sand quarrying is, we decided to jump in and have a go.”
The 60-hectare site has about 10 million tonnes of resource and the business started export by truck in May 2020. Kingscliff Sands’ approval allows up to 300,000 tonnes per year for transport and runs until 2047.
Kingscliff Sands has already made a local impact with its sand products.
“We supply a premium sand and a premium soil to all our local landscape yards,” Holloway explained. “We’ve delivered to people who just want a single load – for backfilling retaining walls – or electrical people for backfilling trenches. Lots of golf courses love our sand for top dressing and repairs and maintenance on their turf. We’ve also had schools use our sands for renovating their sports fields.”
There was an early “win” for Kingscliff Sands when it provided the bedding sand for the base of the new Tweed Valley Hospital. “Once the infrastructure was there, we covered it over with our sand and also put in sand to backfill the retaining walls,” Holloway said. “It was great to work with CD Civil which was the buyer and supplier to the hospital.”
FROM A SMALL START TO WASHING
When Kingscliff Sands opened its doors it hired a mobile screening plant, an excavator and a loader. “We learnt very quickly what size screening we wanted, where we wanted our stockpiles to be and a number of other important factors,” Holloway said. “We then looked at a heap of plants, assessed what was good for our site and then we went to CDE for the washing plant.”
Holloway first met with CDE’s Australasian regional manager Daniel Webber in 2019. Webber told Quarry the brief was pretty simple.
“They wanted to efficiently make a washed sand that could create a quality construction sand blend but they also wanted to explore any other value adds that they could get from the operation’s resource,” Webber explained.
“First and foremost was a washed sand for the construction industry and second, was to say ‘Can the sand be put to more beneficiated uses?’ So they were keen on the likes of glass sand, fracking sand and filtered sand.”
Webber and other members of the CDE team came to site several times to better understand the Kingscliff team’s requirements.
In turn, Holloway visited some of CDE’s customers in Queensland to see examples of its washing plants up close.
“Brad travelled to Caldwell’s on the Sunshine Coast to view plant similar to his,” Webber said. “He also went to Nielsen’s in Brisbane to see some EvoWash™ units that have been working hard for the best part of four years to deliver materials for the Brisbane Airport project. I think those visits gave him confidence in the solution because he saw a system set up in the same application, and he saw an EvoWash™ plant that has been working reliably for an extended period of time.”
After these visits and consultation with CDE, Kingscliff Sands eventually purchased dual EvoWash™ plants, a ProGrade screen, a dredge, a sump tank, a big radial conveyor, and a control module. Holloway described the EvoWash™ as a “high quality washer. It’s been a good fit from the start. Part of our resource offers a high grade silica content for glass, so we have the ability with the CDE plant to plug in a glass washing plant in the future”.
CUSTOMISED CIRCUIT
The full wet processing circuit at Kingscliff Sands was commissioned in February this year. The plant makes two oversize products as well as an organic reject and an all-in washed sand. It comprises a DRS10 dredge that feeds a ProGrade P2-108 two-deck 6m x 1.8m screen. The P2-108 converts a 10mm minus sand into a 2mm minus sand, which is then transferred into a sump tank, pumped into the dual EvoWash™ system and eventually stacked onto a 20m radial conveyor.
“The EvoWash™ is cutting between 63 and 75 microns (μm), so it’s taking all of the bottom end silt out of the material,” Holloway elaborated. “Before it gets to the EvoWash™, it’s already screened the sand at 2mm, producing a high quality washed sand.”
“Brad’s sand is fine, so there is a risk if you don’t have good control over your cut points you could send a lot of sand to the tailings pond,” Webber added.
“We put a lot of emphasis on the primary cyclones and the feed arrangement, and added a scavenger stage – a very fine or small diameter scavenging cyclone – to pick up filtrate and capture that again because we didn’t want to be losing any sand back to the pond.
“The plant has been designed to cut at about 63μm, which is finer than a typical wash plant that might take it to 75μm,” Webber said. “However, it’s not a mining-spec sand, in which we might have to cut even lower than that. So I guess our experience in the mining space, where we have to go down to 38μm or 45μm, has held us in good stead here because we wanted to retain as much sand as we could.”
Webber explained that the EvoWash™ can make two sands but in Kingscliff Sands’ case, this is unnecessary. “Kingscliff Sands can take a bleed string off one of the EvoWash™ machines, so at a later date if they choose to add an extra processing stage for some value added projects, that’s already been future proofed. The provision is there for them to take 50 per cent of the sand off to serve a secondary processing plant.”
Kingscliff’s EvoWash™ plant has other customisations compared to regular EvoWash™ units. “CDE did a lot of civil drawings to raise the two EvoWash™ units off the ground,” Holloway said. “We’re on a floodplain and when the ground floods having the washing plant on plinths keeps the sensitives out of harm’s way.
“We also have a custom-made gate on our plant that is closed to do 100 per cent construction sand, and you turn the gate depending on how fast you want the sands to go into the glass plant for making high quality glass sand.”
Webber said the scalability of the EvoWash™ plant is an advantage for smaller, start-up operations like Kingscliff Sands. “You can start with one EvoWash™ plant and add another one later or a third. They are really robust and no hassle. After we’ve commissioned it with the client and done some basic training, there’s not a lot of tweaking, alterations, monitoring or operator interventions, and that’s essential for a start-up or a new business. They don’t want to be crawling all over their operation and they want to know that they’re keeping their valuable resource on the ground.”
‘JEWEL IN THE CROWN’
The other advantage of the wash plant is it requires few hands to operate, which is important given Kingscliff Sands’ need for efficiency. “We have a control centre with an auto-start and an auto-stop,” Holloway said. “The plant has an LCD screen in the control room. You can walk up to it in the morning and press start and in the afternoon you press stop. Everything else is automated and programmed to start and stop in the right sequence. If there is a malfunction, either with the dredge or the wash plant, then it has sensors, and it will shut down and an alarm will go off.”
Webber describes the control room as the plant’s “jewel in the crown”.
“It takes out all of the surge and fluctuations that are commonplace with dredge operations and gives that stable feed to the wash plant itself,” he explained. “The control room and the traffic light system enables the dredge operator to monitor the health of the plant, and we have sensor technology to safely start and shut down the plant in unexpected circumstances.”
Further, Holloway can be assured that CDE, located in Ormeau, on the Gold Coast, will provide the back-up and the maintenance Kingscliff Sands needs. “Now that I’ve got to know the CDE guys, I can call on one of them at any time and they will answer. There’s definitely lots of support there."