Crushing, Features, Industry News, News, Sand Processing

Astec provides a well-refined screening process

Astec

On the NSW south coast, an Astec 2618VM high frequency screen is aiding Cleary Bros in transforming crusher dust into manufactured sand.

Cleary Bros is a leading provider of construction industry services in the South Coast and Illawarra region of New South Wales. In 2021, the company was searching for a way to produce consistently high-grade manufactured sand at its Albion Park quarry south of Wollongong. An Astec 2618VM high frequency screen proved to be the right fit for the operation, enabling the company to repurpose crusher dust into high-quality manufactured sand. 

Background

Cleary Bros has long been a significant presence in the New South Wales construction services industry. 

What began as a family-run timber mill in 1916 is now a multi-faceted company with over 200 employees.

Among its other operations, Cleary Bros runs a hard rock quarry at Albion Park and a sand extraction site near Gerroa, with the outputs from both delivering raw material for the company’s concrete batching plants in Bombaderry, Albion Park and Coniston. A fully integrated business, Cleary Bros also provides transport, plant hire and construction services to its customers. 

Cleary Bros’ relationship with Astec began in 2019 when the company replaced an ElJay 54 cone crusher with a new Kodiak K400+ cone crusher and surge pile pan feeder. The new equipment performed above expectations, and when the company wanted a high frequency screen to produce quality manufactured sand for its in-house concrete production, they again turned to Astec. 

“We had visited another site that was using an Astec high frequency screen to produce manufactured sand from their crusher dust, and we were impressed with the screen’s capacity and the consistency of the product it was delivering,” Todd Kalajzich, Cleary Bros’ general manager of quarries explained.

Prior to the screening upgrade, Cleary Bros had incorporated an air classifier into its manufactured sand production process – a move that proved to be less successful than they’d hoped, according to Kalajzich. 

“We introduced an air classifier into the process but soon realised there were going to be ongoing problems with moisture levels in the crusher dust as well as with the management of air borne dust from the air classifier,” Kalajzich said. “So we had to find another solution.”

Astec
Using the Astec 2618VM screen, Cleary Bros repurposes crusher dust into high-quality manufactured sand.

Finding the right solution

Matthew Bourke, Astec’s sales account manager for material solutions, worked closely with Cleary Bros on the upgrade project. He explains why the 2618VM high frequency screen was the right technology for the job.  

“High frequency screens differ from conventional screens because the high frequency action is introduced directly into the screen media which allows for increased stratification and separation of material,” explained Bourke. “And that’s the key, particularly when you’re working with finer or wetter materials. 

“Conventional inclined and horizontal screens vibrate on average between 675 and 1000 rotations per minute (rpm). Our variable speed high frequency screens like the 2618VM can vibrate up to 4200 rpm, which is perfect for screening those finer materials like crusher dust.”

According to Bourke, Astec’s high frequency screens are sought after in a range of other processing applications too, including recycling asphalt, glass and nickel slag. 

“Depending on the properties of your resource, the removed fines can even be used as a natural fertiliser or recombined back into road base,” Bourke said. 

“In this case, Astec’s high frequency screen technology is helping our customer modify the gradings of crusher dust to produce a highly valuable product which, in turn, reduces the demand for natural sand,” he added.

“It’s a win-win for everyone.”

On the Cleary Bros site at Albion Park, the Astec 2618VM is at the centre of a simple production circuit. The screen was purchased first, then Cleary Bros built a support structure, conveyors and product delivery bin. 

“The design of Astec’s high frequency screens makes them easy to install and operate,” Bourke explained. “Because the vibration is isolated from the side sheets and applied directly into the screen media, there is no dynamic load on the support structure, so the structure required is much smaller than for conventional screens.” 

The advantages don’t end there.

“The 2618VM is versatile and flexible,” Bourke added, “with multiple adjustments available to improve performance. These include screen angle, rpm and amplitude. And screen media changes can be made quickly and easily with our unique rotary tensioning system that utilises a winch and spring system.”  

Astec’s range of high frequency screens includes both fixed and tracked options. Cleary Bros’ 2618VM is a double deck six-feet by 18-feet high-frequency screen.

The result

According to Kalajzich, the Astec 2618VM has given Cleary Bros far greater control over the quality and consistency of the product. 

“Moisture levels have a considerable impact on the process, and now we’re able to adjust the rpm and inclination to account for those,” he said.

Maintaining that consistency is key to Cleary Bros’ operations, Kalajzich added.

“Stringent specifications for manufactured sands require continual testing and management of our 75-micron content to ensure we produce consistently compliant material, and with the 2618VM we can do just that.”

According to Kalajzich, upgrading to the Kodiak 400+ crusher and installing the Astec high frequency screen enabled the company to improve the quality of its concrete. 

“Our aggregate shape and yields improved with the introduction of the Kodiak K400+ cone crusher, and that has many benefits down the line, particularly in terms of concrete strength. And with the new 2618VM high frequency screen, we now have a reliable supply of compliant manufactured sand. Both are proving to be important factors in our ongoing success,” he said.

Like other quarries on the South Coast, Cleary Bros has had to navigate local and global challenges in recent years. From bushfires in late 2019, through the long uncertainly of the Covid pandemic, to months of continuous wet weather, it’s been a difficult period for any business to negotiate.

However, as Kalajzich explained, the company has been able to adapt and maintain a pipeline of both supply agreements and construction works by being “innovative and flexible,” and Astec has been a big part of that.

“We have a great relationship with Astec. They’re always available and their ongoing support has been excellent. We’re delighted with their products – they’re well designed, robust and reliable. Exactly what you need in the quarrying environment.”

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