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Washing plant hails start of friable sand business

 

A greenfield sand operation is set to meet the high demands of the Greater Sydney market after the launch of a bespoke washing circuit.

Based in large purpose-built premises in North Penrith, Western Suburbs Concrete (WSC) is one of Western Sydney’s largest pre-mix concrete suppliers. WSC specialises in an extensive range of ornamental, general and premium concrete products for the Western Sydney, Greater Sydney and New South Wales markets, including pre-mix, decorative and blockfill concretes, as well as self-compacting, post-tension, kerb and gutter, and green star mixes, and spray mixes for swimming pools and the walls of underground tunnels, canyons and car parks. WSC can also manufacture full depth colour concrete swatches for its customers. 

Peter Vicary, who is WSC’s managing director, told Quarry that the family-based business was started by his father in 1987 and he had been a part of it for all of his adult life.

“I started here in 1991 and in the 2000s, when I was 25, I bought my dad out,” he reflected. “We’ve grown from a very small operation of about 15 trucks on a 2000m2 site to now having the largest batch site in Sydney with the largest output, and we’re really the market leader in the western suburbs of Sydney. That’s been done through building trust with our clients over a number of years, and that trust comes from doing what you say you’re going to do and honouring your commitments in terms of service and quality. They’re the big things for us.

“That’s what we’ve focused on intently over a period of time and from that we’ve built a lot of great relationships with our customers,” Vicary added. “The biggest thing is our customers can rely on our service and quality, and that rolls off the tongue pretty easy but there’s not really many concrete suppliers out there that customers can rely on their service and quality con[—-tinuously.”

While WSC has been involved in concrete manufacturing and transport for nearly 35 years, it is only in the past two years that it has actively diversified into the quarrying sector. In 2019, the company leased a 129ha virgin sand site in Clarence, between Lithgow and the Blue Mountains. WSC began building all the infrastructure for the new site in early 2020 and commissioned its sand plant operations in July 2021. Trading under the name of Clarence Sands, the new quarry site is now supplying quality sand products throughout NSW, including Metropolitan Sydney, Lithgow, the Blue Mountains, Bathurst and Orange. 

In just a few short months, Clarence Sands, in conjunction with WSC, has already supported several large projects in the Greater Western Sydney region, including the new Amazon facility and a Coles supermarket depot in Erskine Park. Vicary said the company is also in discussions to supply its materials to the Western Sydney Airport project.

Clarence Sands operates on top of a friable sandstone deposit, which Vicary said is very different from most sandstone deposits. “It’s extremely friable, almost like a beach sand,” he explained. “The clays and silts that are present in our sandstone are quite different to other sandstone quarries, so we produce a very clean, premium grade concrete sand for the Sydney Metropolitan area. It’s finishing characteristics are excellent, it has next to no impurities and an extremely low silt content in the finished product.”

From that friable sandstone deposit Clarence Sands is producing two types of sand. “Ninety per cent is a fine sand that we use for our concrete production,” Vicary said. “The other 10 per cent is a coarse sand.”

Terex Washing Systems brought in a revamped 6m x 2.4m two-deck screen module to process the high tonnages of sand before sending it to the washer.

ONE-STOP-SHOP TURNKEY

In order to produce a premium quality construction sand for the Greater Sydney and NSW markets, Clarence Sands put out a tender for a sand washing plant.

“The key requirement for us was the tonnage capacity per hour, and to be able to produce two different grade sands out of the one raw feed,” Vicary said. “We also needed to have a thickener that could process and handle the clay silts and fines that were being generated out of the washing process. The plant also had to be all automated.

“In fact, while a competitive price was also important, what we really wanted was a one-stop-shop turnkey. We didn’t want to have to deal with different suppliers providing us a cyclone here, a vibrating screen there and a thickener tank separately,” he added. “We wanted one supplier to turn up on-site, build it, and hand it over, and that supplier would be responsible for everything in the plant. That was pretty important to us.”

Clarence Sands purchased its 300-tonne per hour (tph) sand plant from Terex Washing Systems (TWS), the washing solutions subsidiary of Terex Material Processing Solutions (Terex MPS) globally and Terex Jaques in Australia. 

Ben Willcox, the Australian and New Zealand sales manager for Terex Washing Systems, said that Clarence Sands’ brief was relatively straightforward. 

“The challenge was the tonnage,” Willcox said. “It was a niche tonnage, so we called on the sister side of the business – the MPS side – to bring in a quarrying screen and then developed a rinser station to handle the tonnage. We redeveloped a 20’ x 8’ (6m x 2.4m) two-deck screen module, the largest we’ve done for this sort of operation. The benefit of this was we were able to minimise the footprint and cost. This plant is designed to pass the material over a single incline screen, and then split it into two grades of sand, which was a challenge in itself. The screen has a split bottom deck, so you’re taking the fine sand out of the top half of the bottom deck and then the coarse sand out of the bottom half of the same deck. It’s making two grades of sand over one deck. It’s capable of producing 2.5mm and 4.5mm grades of sand.”

The Clarence Sands plant and circuit consists of two Finesmaster 200 sand recovery units, centrifugal slurry pumps, hydrocyclones and a dewatering screen on a single chassis. The Finesmaster is capable of recovering saleable material through the removal of silt, slimes and clays below 75 microns (or 200 mesh) and reclaiming up to two grades of sand from a wet feed or an optional bolt-on boiler box for a direct dry feed. The high frequency dewatering screen can reduce residual water content in the final product by between 85 and 90 per cent. It is complemented by a self-regulating cyclone tank and rubber-lined pumps. An electrical control panel and spraybars for dewatering stations are also options.

The twin Finesmaster 200 sand recovery units.

RAKE THICKENER

The other challenge for Terex Washing Systems was contending with the volume of silts and the size of the thickener that was needed for the tonnage. 

“We chose a rake thickener, which is certainly the largest in our range of thickeners,” Willcox said. “In fact, I don’t think anyone else in the industry has a thickener of that size. It’s 18m for the thickener.”

A rake thickener is designed to specifically process high volumes of slurry. Its scrapers transport the material from the outskirts of the tank to the outlet, accelerating sludge removal from the thickener. The sludge output features between 30 and 40 per cent of solids content. Rake-style, high rate thickeners like the one employed at Clarence Sands allow for minimal feed height, thereby accelerating the gravity feed from upstream cyclone-based washing systems.

Willcox said that, aside from the water tanks and the thickener, the plant is modular. The Finesmaster 200s in particular have an easy to assemble steel construction, complete with galvanised walkways and hand rails for easy access, and all electric plant can be pre-wired before assembly to control panels or isolators to integrate with other equipment.

Willcox described the Clarence Sands plant as “a custom bespoke-able plant using standard items. It has the ability to wash and blend sand at multiple points, to give Clarence Sands the ability to meet their product requirements. The nature of the source material is the silt. We have five different points of washing silt out, so it’s very adaptable to the products”.

A plant of this scale, Willcox added, could produce up to five products – two sand and three aggregates – if it was in the resource. However, due to the friability of the sand resource, the Clarence Sands plant is only producing the two products: a coarse sand and a fine sand.

As a testament to its modularity, the units within the sand washing circuit – the Finesmaster 200s, the rake thickener and 6m x 2.4m incline screen – can operate independently. “If Peter was to sell the plant, we could break it up into individual items and sell them off, and most of them would be able to run by themselves,” Willcox said. “On this occasion, it’s a purpose-built plant, so we can meet any customer’s requirements with any piece of equipment.”

The sand plant is fully automated and Clarence Sands employs one operator at a time – out of its seven-strong crew on the ground – to run the circuit. That person can monitor the plant’s progress from a mobile control centre over the course of the day.

COMMISSIONING CHALLENGES

The automation capabilities of the Clarence Sands circuit are further made possible with the Terex Washing Systems 4 Site program. Initially launched at the Bauma construction show in Europe in 2016, 4 Site is a project management service which offers Terex Washing Systems customers enhanced levels of support at every aspect of their operations – from set-up to commissioning to aftermarket. Three packages – silver, gold and platinum – are available to the client and each package incorporates four steps: appraisal, planning, support and installation.

Willcox said 4 Site had been particularly useful as a remote assistance tool during installation. “COVID has posted some challenges for this plant  but we’ve still been able to help get Clarence Sands operational as needed. On this occasion, 4 Site has worked really well, especially with the lockdown in NSW, so we’ve been able to dial into the plant and assess the diagnostics, and answer any questions of the operators. I can pull up the programmable logic controller (PLC) display of the plant at Clarence Sands and tell you how the sand plant is running right now. We have a clear view of what they can see on the panel and can help with making any changes required. It saves a customer callout.

“The 4 Site program comes standard with any major plant,” Willcox added. “Typically if it is a smaller plant, there’s no real requirement for 4 Site. But when there are PLCs and water management involved, you need the ability to dial in and assist wherever needed. We can see the chemical usage, the water flow rates, and if a new operator comes on board, they can easily dial in.”

Peter Vicary agreed that the 4 Site program was very helpful for troubleshooting – “If we have a problem, we can get Ben on the phone and then in a few minutes he’s in the system helping us to rectify it” – and added that Terex Washing Systems service throughout the installation and commissioning of the plant was exceptional.

“TWS’s service was great,” Vicary said. “Any time we needed them, they got onto things as quickly as the circumstances allowed them to. I think every quarry has its unique attributes and things that are unique to that resource, and Terex had to attune their plant to our resource, which I think they did in a reasonable period of time.

“By the time we started commissioning the equipment, Ben was able to return to site and conduct live, on the job training with the new operators we recruited to run it.”

FUTURE-PROOFED

The Terex Washing Systems sand plant was commissioned in July 2021 and has been operating for nearly five months. Vicary has been very satisfied with its performance.

“It’s fantastic. It’s doing 300 tph, all day, every day, and it’s making beautiful washed sand as well,” he said. “The water management system is really good as well. We dug some stuff out of our pond the other day – and it was thick enough that when we placed it above the ground, within five days you could push it up into a heap. That’s on top of lots of rainy weather. It’s going to make the pond an easier process because it’s all going to dry up once it’s above ground. It means the pond will dry quicker.”

Vicary said there is scope for Clarence Sands to sell by-products from the pond silts and clays, potentially for applications in dam linings, dump cappings and landfill, but that the business’s priority is to produce the construction sand for WSC’s operations first and foremost.

“We can grow into that plant,” he said. “It can process over a 12-hour shift more than 3600 tonnes per day, so we bought a plant big enough that we could grow into it as our customer demands increase. We’re future-proofed.”

Vicary said he would recommend Terex Washing Systems to other quarrying producers, especially when it comes to local service.

“My advice is to use someone that has local service technicians on the ground in your area, and aftermarket support and back-up,” he said. “During the commissioning process, we broke a few things and Terex needed to fix some things, and the guys were only 90 minutes away and if we needed someone to come, they were here straight away. 

“I’ve heard stories of other companies not having that back-up service on the ground, and it can be a big problem. When you have the pressures of production and customer demands that you need to meet, and your plant goes down and people can’t get there for days to fix it, then that’s a big problem. So that’s important, you can’t afford to have a plant break down and no one available to fix it.

“We’ve been impressed and pleased with the whole process. When you’re building a complex wash plant, there is always going to be some difficulties to get through in the commissioning process, so it’s reassuring knowing that we have the back-up.” •

Source: Terex Washing Systems.

To learn more about Clarence Sands, visit clarencesands.com
For more information about Terex Washing Systems’ sand washing plant and equipment, visit terex.com/washing/en/Australia

This article appears in the December issue of Quarry Magazine.

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