Promoting ?waste to resource? in a sustainable industry

Across a very diverse range of materials, Marius Snyman, the regional manager for CDE in Australia, has said that the company’s core purpose remains consistent – helping its customers “transform what was previously seen as a waste product into a valuable resource. This is where the business began in 1992 and it remains at the very centre of everything we do”.

To understand what CDE represents today, it helps to revisit the company’s foundations.


Current chairman and company founder Tony Convery started to develop hydrocyclone and dewatering screen-based sand washing systems in 1992 to ensure a higher quality, drier sand product. This was founded on the desire to eliminate the loss of quality fines to on-site settling ponds.

“Traditional sand washing systems had a number of limitations – inaccurate cut point or separation efficiency and an inefficient dewatering system that resulted in a low quality final product with moisture content often in excess of 25 per cent,” Snyman explained. “This is why CDE’s EvoWash was created and its continued success over the last 20 years is testament to how it was built on an in-depth understanding of the issues that sand producers were facing – and continue to face.”

In the sand and aggregates business, the EvoWash is employed extensively on both the processing of natural sands and the production of crushed rock fines to produce manufactured sands. In recent years, CDE has built a portfolio of projects on this very theme.


“We have a number of plants in New South Wales producing manufactured sands for use in concrete and asphalt,” CDE’s business development executive Kasey West Kehoe-Cox said. “In Coff’s Harbour, our M2500 modular washing plant is employed to produce manufactured sands for use in concrete manufacturing.”

The M2500 is part of CDE Global’s M-Series family and integrates feeding, screening, sand washing and stockpiling capability to allow production of up to five washed and classified products from a single, compact unit.

A key success in the Coff’s Harbour project is the integrated water recycling capability. The AquaCycle thickener allows for 90 per cent of process water to be recycled which is a theme that is becoming increasingly common across Australia, as Kehoe-Cox explained. “Access to water can be an issue – for hard rock quarries in particular – and our AquaCycle technology allows operators to enjoy the benefits of our advanced wet processing technologies while significantly reducing the volumes of water required,” he said.

Two more customers in New South Wales are using the EvoWash system to produce concrete sands from their sandstone waste material. “We were able to demonstrate how the EvoWash had the capability to turn this sandstone waste into a valuable resource,” Kehoe-Cox said. “As well as producing sandstone blocks our customer is now also selling manufactured concrete sand to the Sydney market where there are significant infrastructure projects currently underway.”

As well as recovering valuable material from waste stockpiles, a large number of CDE projects are involved in preventing the loss of quality material to settling ponds. “We’re often approached with a requirement for a fines recovery system to address the loss of quality fines to ponds as a result of inefficiencies in the sand washing circuit,” Kehoe-Cox said. “Our approach to this is that we could use a sticking plaster – but surgery is required. The correct solution is to replace the inefficient system with a custom-built EvoWash – and eliminate the problem rather than addressing a symptom.”

The Nielsen Group in Brendale, Queensland introduced the EvoWash system precisely for this reason. Nielsens introduced the EvoWash 151 to address the time spent on expensive pond excavation and reprocessing. “Our experience has shown that typically 10 to 15 per cent of quality fines will be lost to the settling ponds when traditional sand washing technologies are employed,” Kehoe-Cox explained. “The EvoWash eliminates this problem – not only increasing production volumes but also resulting in a higher quality product and reduced space and cost associated with pond management. There are also obvious health and safety advantages associated with reduced pond excavation requirements.”

“This approach is important as it demonstrates how we as equipment manufacturers can work closely with construction materials producers to ensure the industry operates in an efficient and sustainable way,” Snyman said. “Whether it be water savings from the AquaCycle thickener, the creation of commercial products from waste stockpiles or preventing the loss of quality material to the settling ponds we understand our role is to help our customers ensure the sustainable exploitation of our natural reserves – maximising product yield and minimising waste.”



From its foundations in the sand and aggregates business, CDE Global has developed capability in other areas – once again with the “waste to resource” as its theme. In 2004, the company started to develop technology for the effective recycling of construction, demolition and excavation (CD&E) materials.

This technology was originally developed and employed in the UK market in response to diminishing natural reserves, depleting landfill space and the need for an alternative source of construction materials.

“It was a natural progression for us and an area that has been very strong in recent years as awareness grows about the potential uses for recycled materials when advanced processing systems are employed,” Snyman explained. “We’re effectively ensuring that this material is up-cycled and is able to be used in high value construction applications – when using size reduction and dry screening for this material, the field of application is very limited and typically involves very low value final products.”

CDE is yet to deliver a CD&E materials recycling project in Australia but its global portfolio is growing with projects completed in the UK, Norway, Sweden, India, Germany and Aruba in recent years. According to CDE, the market drivers that were apparent in the UK and led to the development of the technology are now appearing in other areas of the world – including Australia.

According to Kehoe-Cox, the main opportunities for these systems are in Sydney and Melbourne in the short to medium term. “They’re the fastest growing cities in both infrastructure and residential development. Sydney has simply run out of resources within itself, and it is now quite common for projects to be sourcing material as far north as Newcastle, as far south as Wollongong, and even most of the way to Canberra. Now is the time for change in this industry to help with infrastructure growth and support construction sustainability.”

The current diversion from landfill to CDE recycling plants is more than seven million tonnes. One of the major project successes was the installation of a plant into Stuttgart, Germany on a project supported by the EU to help increase recycling rates in Europe and increase the value of the recycled material. Germany is one of the most well developed recycling markets in the world and CDE technology was elevated as a means of demonstrating how CD&E materials should be dealt with. The European Quality Association for Recycling (EQAR) commended this project as a result of the potential it offered to enhance the perception of recycled materials and encourage further adoption of this technology.



The industrial sands arena is a broad one and covers a wide range of materials. It has been an area of focus for CDE in recent years – with major successes in Adelaide and Bundaberg, Queensland, with turnkey glass sand projects for Tooperang Quarry and Earth Commodities. This has enabled CDE to develop supply relationships with Owens Illinois (O-I) for its Asia-Pacific glass production facilities.

“The sports sands area is an interesting one from a waste to resource perspective,” Kehoe-Cox remarked. “Often as a result of producing concrete or asphalt sand for our customers we can be left with fine sand as a by-product. Rather than accepting this as a waste material we work with customers across the world to produce sand for use in the construction of golf courses. The result of this is the transformation of a waste product into a high value sports sand.”

An industrial sand project for Boral Moora – north of Perth, Western Australia – is processing a high quality quartzite, with the product being used by Simcoa in its silicon production processes. The ore is typically 25mm to 75mm in size and everything in the 0-7mm range was previously sent to settling ponds as a waste product. The CDE system now recovers the valuable ore from the 63 micron to 5mm range and significantly reduces the volumes of water being sent to the ponds. The water used in the recovery of the 5mm ore is recovered for reprocessing, addressing a problem with water availability for Boral.


Across the mining projects completed by CDE, the “waste to resource” theme is also evident. An iron ore project in Brazil is removing sticky clay from the ore and allowing waste dumps of iron ore to be effectively reprocessed, while also increasing the working life of the mine by allowing the processing of material previously seen as too difficult and expensive to handle.

In South Africa, CDE Global is working on a gold mining project to isolate small quantities of gold found in the finest fraction of waste dumps and produce a concentrated gold ore that can now advance to recovery and further processing.

Most significantly in Australia, a recent project has begun with Arrium Mining that will see CDE install two iron ore processing plants in South Australia in 2017. Both of these projects will involve the processing of low grade iron ore currently stockpiled in waste dumps. The annual processing capacity of both these plants will be close to eight million tonnes.

“By tackling the silica, alumina and clay contaminant levels with the stockpiled ore we are able to significantly increase the iron levels in the ore and make it viable for use in steel production,” CDE Mining’s technical department manager Chris McKeown said. “The recovery of low grade ores from waste dumps is a recurring theme across all of our mining projects and it is an area where we expect to see significant growth in the years ahead. These major projects with Arrium Mining will gain worldwide coverage and open up new project opportunities.”



Another example of where CDE has successfully diversified into new sectors is the performance of CDEnviro since it was born as a business unit in 2008. Formed as a separate company in 2011 the company now enjoys significant export successes in Europe, North America and Australia as a result of the development of new technologies for the waste water treatment, recycling and material recovery markets.

One area of notable success has been the road sweepings recycling technology that is now used by some of the world’s largest environmental companies.

“The vast majority of road sweepings is mineral material – sand, grit, gravel, larger stones,” Darren Eastwood, the head of business development at CDEnviro, said. “We’ve developed the technology which allows this material to be recovered and efficiently separated from organic and other contaminants to provide an end product for use in construction projects.”

In addition to its road sweepings technology, CDEnviro has also developed a system for the recycling of waste glass for re-use in the glass manufacturing process. This is an area of growth across the world at present and one where CDEnviro has already achieved some project successes. In addition to this the company is also involved in the development and execution of projects for hydro-excavation and drilling muds as well as sludge screening in municipal and industrial waste water treatment applications.


With an ever growing project portfolio across a broad range of sectors, what’s next for CDE in Australia?

According to Snyman, it’s about building on the solid foundations of recent years and continuing to partner with customers to increase the efficiency, sustainability and profitability of their operations. He added that the direct contact between CDE and its customers is critical to the success it has enjoyed to now and into the future.

“Our direct sales approach, our focus on building the best technical team in the industry and our unique focus on wet processing technology ensures that no other manufacturer is able to get as close to their customers as we are. Our understanding of the day to day issues that need to be addressed and the new challenges being faced ensures that we are well placed to continue to meet the demands of our customers and help them to drive their business forward. This approach works in tandem with a relentless focus on innovation that allows us to continually develop new ways to solve old problems.” 

Source: CDE Global

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