Walker Quarries sets up for growth


Walker Quarries is about to roll out one of the most technically advanced wash plants in New South Wales, thanks to the options and consultancy provided by CDE’s engineers.

In 2018, when Trevor Hoffmann, operations manager at Walker Quarries, approached the team at CDE, he was looking for a sand washing solution that could be tailored to the specific requirements of their operation.

Located near Wallerawang, just west of Lithgow in New South Wales, Walker Quarries mines hard rock quartzite, which is then crushed on-site to make construction aggregates and manufactured sand, among other products.

Having commenced production since 2015, Hoffmann said Walker Quarries was looking to expand its production level.

“We’ve been making very consistent quality sand with our basic sand plant at Walker Quarries for the past seven years. Our current capacity is between 50 to 60 tonnes per hour, but we knew that if we wanted to commit to new clients and expand our market, we needed to get bigger,” said Hoffmann. 

The team at Walker Quarries conducted an exhaustive vetting process, which included Hoffman taking a trip to the Bauma 2019 exhibition in Germany. Having reviewed multiple options available on the market, the best solution for the quarry came through collaborative work done by CDE.

“When we started researching plants, we went across the country looking at all different brands. The CDE ones were the most impressive and, from our experience, very well constructed,” said Wayne Chapman, mine manager at Walker Quarries.

After the initial consultation, Hoffmann said CDE and Walker Quarries embarked on a journey to design a sand washing plant specifically tailored to the quarry’s needs, which included working on all aspects of the process, from hopper feeds to tailings management and even the final product stacking. The plant also includes a filter press to help the quarry increase its water retention.

“We currently have water stored in our storage dam with reserve capacity. But we wanted to add a backup system. With our filter press and our water system in place, I think we’re going to be reasonably drought proof for the years to come,” Hoffmann said.

Tailored design

Daniel Webber is the CDE regional manager who has been working on the project with Walker Quarries. He explained some of the aspects considered in the design.

“One of the big issues for the site was water scarcity and space available for settling ponds. If Walker Quarries was going to increase production, then they would need to find more water and more space to settle out fines if they were to use their old method of washing,” said Webber.

“Being experienced operators, the team at Walker Quarries wanted to make sure they could sustain the next drought, given their relatively limited footprint for catching rainwater. As such, they wanted to reduce their dependence on water harvesting and maximise their water recovery,” he added.

To this end, CDE did a lot of work around tailings management, including press testing. The plant has been designed with a filter press to help increase water recovery and treatment. The fines from the process are thickened into a sludge and treated with the filter press into dry tailings, allowing the treated water to return to the system.

The material gathered from the filter press that has been developed also ensures that the maximum amount of saleable product is obtained from the processed quartzite.

Webber said product quality and adaptability were other key aspects to consider during the design.

“The main sand wash plant will produce coarse and fines washed sand, which can be made independently or blended via CDE’s Dual Sliding Product Conveyors. This will give Walker Quarries a lot of flexibility and the ability to make spec products,” he explained.

“Also included in the plant is an AggMax scrubbing module, which will recover clay bound sand from the dirtier feed materials. It will also produce scrubbed construction aggregates and, from time to time, round pebble. Since the scrubbing plant isn’t always required, we’ve designed it so that the module can be can be taken offline by radially moving away it’s feed conveyor so you’re not getting undue wear and tear from materials that don’t need to be scrubbed,” he added.

A strong relationship

According to Hoffmann, the support from the CDE team has helped Walker Quarries not only overcome some of its earlier “setbacks,” but also to add new potential sources of revenue.

“The filter press is going to eliminate some of the risks and environmental setbacks we faced with the basic sand washer. It’s also going to eliminate a lot of the maintenance costs. Another big bonus is that we’ll now have a very good supply of materials for future processing.”

With a name plate feed rate of over 200 tonnes per hour, the new Walker Quarries’ plant will be one of the most technically advanced wash plants installed in New South Wales when it starts operation in January next year.

Hoffmann said the support received from the CDE team was instrumental in developing a fit-for-purpose solution.

“They’ve been very informative and providing us consultation right from the start. And once we signed the contracts, an engineer from CDE was assigned to work with us on a weekly basis,” he said.

According to Webber, the relationship has only grown over the past few months. 

“We’ve certainly come a long way since that early enquiry from Walker Quarries in 2018. With the plant getting ready for commissioning, there’s been a relatively seamless handover from CDE’s regional sales team to the local project manager. The next phase will be handing over to our aftersales customer care team for the lifetime maintenance of the plant,” he said.

CDE has also equipped the plant with a remote monitoring system to facilitate fault diagnosis by CDE’s engineers in the event they can’t be on site. 

“CDE is extremely excited that this project is approaching commissioning and completion,” said Webber. “It has been a pleasure to work with Walker Quarries and both parties can’t wait to see sand rolling out the gate.” •

Send this to a friend