Sustainable mining gains traction: CDE

Adam Holland, CDE Meta, speaks with Waste Management Review about how wet processing can transform mining waste into a sustainable value-added resource.

While sustainable mining might appear like a contradiction to those in the stereotypically green resource recovery industry, it’s a movement that’s gaining global traction.

With rising demand for quality metals, in addition to increasingly stringent environmental legislation, protecting finite natural resources and extracting value from “waste” is not just environmentally sound, but good business.

For CDE Meta, the mining arm of international wet processing design and manufacturing company CDE, delivering sustainable mine operations via iron ore beneficiation is central to its “New World of Resource” purpose.

According to Adam Holland, CDE Meta Head of Business Development, with billions of tonnes of low-grade and overburden iron ore stockpiles around Australia, there is a growing appetite to invest in sustainable practices.

“CDE strives to make it as easy as possible for companies to use their waste products for the greater good, while also delivering return on investment,” Adam says.

“We’re committed to maximising product value while reducing environmental impact. Sustainability is at the heart of all CDE projects.”

CDE was recognised for its commitment earlier this year, winning two awards, one in Ireland and one in South Australia, for its Iron Baron and Iron Knob projects with SIMEC. The two awards, gained on the same day at opposite sides of world, are a testament to the global reach of the company and the strength of its sustainability driven purpose.

The awards, Adam says, highlight that while sustainable mining might not be taking over the sector just yet, solutions are available, and a return on investment is possible for resource companies interested in taking a greener approach.

The SIMEC projects, commissioned in 2017, involves two separate wet processing plants with a combined capacity to convert 17 million tonnes of historic low-grade iron ore overburden waste into a high-value product. Without processing, iron ore waste often sits in unused stockpiles.

“With a processing capacity of 950 tonnes per hour, the two plants are successfully recovering high-quality iron ore from 100-year-old-plus-low grade mining waste feed material,” Adam says.

“Our plants beneficiate iron ore waste at 42 to 53 per cent Fe content through washing and gravity separation up to 63 per cent, at an almost 50 per cent yield.”

CDE was approached by Arrium (shortly after it was acquired by SIMEC) in 2013, before signing a design and construction contract in 2016.

“Because they were dealing with a historic stockpile, and therefore variable feed, SIMEC recognised CDE’s modular approach as a differentiating factor with inbuild flexibility,” Adam says.

“SIMEC understood the inherent value of its iron ore waste but needed our assistance to develop a cost-effective beneficiation solution.”

While the plants, Iron Baron and Iron Knob, engage similar processes, Adam says the Iron Baron facility is more complex – beginning with a 42-millimetre down feed.

Each process module is spaced out and separated by conveyors and pipe runs. This, Adam says, provides operators with superior access and flexibility when maintaining the plant and allows additional processes to be added for optimisation with minimal downtime to cope with feed material that changes periodically.

The Iron Baron process begins with two L55 hoppers, each feeding 350 tonnes of material per hour. Conveyors then transfer material into CDE’s patented P2-108 double deck infinity screens which wash and split the ore between fine and course beneficiation circuits.

Following initial screening, the course fraction travels to CDE’s AggMax – a combination of a Rotomax logwasher and dewatering screen.

“This is where the ore is scrubbed to liberate any smaller particles and break off impurities,” Adam says.

“It has performed exceptionally well – running for well over a year before we had to change out the paddles.”

Once the material is cleaned and scrubbed, it travels up more conveyors for dry screening, and then enters a fine or coarse jig for gravity separation.

“The plant then separates material into three stockpiles: a course product, fine product and rejected material,” Adam says.

“Given the nature of our process, however, even the rejected material can be reclaimed, with SIMEC using it for road construction around the mine.”

Adam says attention to maximum reuse was also behind the decision to install AquaCycle thickeners at the site. The thickeners, he says, produce a sludge from the reject slimes and enable recycling of 90 per cent of process water back through the plant.”

Additional benefits of the unique CDE modular solution, Adam says, include minimal civils, a faster, safer and reduced risk installation due to factory testing and per commissioning process, as well as reduced capital and operational expenditure.

“What sets these plants apart is CDE’s ability to design a modular solution, tailored to SIMEC’s unique requirements, delivered on a turnkey basis for cost-effective operations in a mining and iron ore context. This provides a superior return on investment for SIMEC,” he says.

In addition to effective return on investment, Adam says CDE is committed to providing ongoing customer care, adding that it works with a “customer-for-life model”.

“As part of this project, CDE has also invested in a significant vendor-held spares consignment that SIMEC can draw down as and when required,” he explains.

“We also have two full-time employees who work at the site and support SIMEC through maintenance and manage the VHS consignment, ensuring that bin levels are replenished for optimal plant performance.”

Adam says he hopes CDE’s SIMEC plants serve as a case study for larger resource companies seeking to increase operational sustainability. He adds that for every tonne of ore waste processed, mining companies can significantly extend the life of their mine and maximise reserves.

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Tellus Holdings secures approval for Sandy Ridge project

Infrastructure development company Tellus Holdings’ Sandy Ridge facility has received approval from the Western Australia Mid — West Wheatbelt Joint Development Assessment Panel (JDAP).

The project is a kaolin mining operation which will include a waste facility for the permanent storage of hazardous waste.

It will require the commissioning of the waste cell infrastructure, access roads, raw water supply and other key infrastructure for the waste facility.

Tellus Holdings General Manager for Health, Safety, Environment, Compliance and Quality Richard Phillips said the approval signifies government are confident Tellus Holdings has considered, and can manage the potential benefits and risks associated with operating a dual business model.

“It means the Sandy Ridge Facility, Australia’s first dual, near-surface kaolin clay mine and complementary storage business, has now achieved environmental and planning approval from the federal government, state government and local government,” Mr Phillips said.

The JDAP unanimously approved the Sandy Ridge Facility on 3 April, subject to nine conditions and five advice Notes.

The nine conditions include requirements for bushfire management, emergency response management and traffic management.

The conditions must also adhere to the Ministerial Statement Number 1078 granted under part IV of the Western Australian Environmental Protection Act 1986 in June 2018.

Tellus Holdings Managing Director Duncan van der Merwe said the company has undertaken extensive environmental and engineering studies involving local, national and international experts and key community stakeholders.

“Once again, this latest approval is a show of support for Tellus’ evidence-based and risk-based environmental assessment. It is an important next step in securing the remaining approvals required for the Sandy Ridge Facility,” Mr der Merwe said.

Tellus Holdings will continue to liaise closely with Western Australian agency to secure remaining approvals and licensing.

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UQ develops mining waste solution

Development of a mineral gel technology that will provide effective, low cost, rapid management of toxic red mud from alumina refineries has received a major financial boost.

Red mud is the waste product generated by the production of aluminum oxide, or alumina.

University of Queensland Sustainable Minerals Institute researcher Dr Tuan Nguyen has secured almost $500,000 to develop the gel technology that will transform the way refineries manage waste sustainably and economically.

Dr Nguyen said the gel had the potential to minimise pollution risks from red mud storage.

“New and cost-effective technologies are urgently required to assist the refinery industry to operate with much improved environmental outcomes,” he said.

“Safely storing and processing red mud is difficult, costly and time-consuming.

“But the gel chemically links mineral grains into stable and benign soil-like structures so it can sustain plant root systems, resulting in a successful rehabilitation outcome.

“This will help massively with seepage management and red mud rehabilitation.”

Dr Nguyen won a $180,000 Advance Queensland Industry Research Fellowship last week.

Rio Tinto and Queensland Alumina Limited have topped that up to almost $500,000, contributing cash and in-kind support.

“This funding is an outcome of strong collaboration between research and the environment teams of industry partners Rio Tinto and Queensland Alumina Limited, which produce $6 billion of alumina a year,” Dr Nguyen said.

“They accumulate millions of tons of red mud which is stored across 1500 hectares of dams in Central Queensland.”

Dr Nguyen recently joined the Sustainable Minerals Institute to work on research to develop cost-effective and sustainable technologies for rehabilitating red mud dams in Queensland and the Northern Territory.

Research group leader Associate Professor Longbin Huang said the technology was an important part of a new research theme of ecological engineering of mine wastes.

“Tuan’s appointment and the jump-start of this excellent funding opportunity are likely to lead to significant advancement of new technology to rehabilitate toxic red mud,” he said.

“This technology will help establish a red mud rehabilitation industry in Queensland, and make The University of Queensland the leading hub of red mud research and applications.”

Veolia to deliver water treatment plant at Talison Lithium Mine, WA

Veolia Water Technologies has been selected to deliver a water treatment plant at the Talison Lithium Mine in WA.

The mine, located in Greenbushes, is the biggest hard rock lithium mine in the world. The Greenbushes Lithium Mine Water Treatment plant will be constructed utilising some of Veolia Water Technologies products.

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Veolia Water Technologies will provide a water treatment plant solution based on ACTIFLO clarification, CeraMem ultrafiltration, high recovery RO and two stage EVALED thermal evaporation.  The plant is designed to treat a maximum feed flow of 150 metres cubed and hour to recover the most water as possible.

It aims to double the output from the Greenbushes Operations and satisfy environmental requirements to reduce lithium contained in onsite mine water before it is discharged into environment.

Veolia Water Technologies specialises in water and wastewater treatment solutions to the private and public sector and design, build, operate and maintain wastewater treatment facilities.

Lithium from the mine is used in batteries, busses and passenger vehicles, aerospace allows, wind turbines, glass and ceramics.

Preliminary activities have commenced, and the construction of the water treatment plan is expected to be completed and operational in 2019.

Veolia selected to deliver Springvale WTP

Veolia Australia and New Zealand has been chosen by Springvale Joint Venture and EnergyAustralia to deliver the new Springvale Mount Piper Power Station Water Treatment Plant (Springvale WTP).

Veolia will partner with Australian based Infrastructure Capital Group to fund the project, located in New South Wales’ Central West region.

The Mount Piper Power Station provides approximately 15 per cent of NSW’s power, and the Springvale WTP will be built under a build, own, operate and transfer contract.

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It has been commissioned by EnergyAustralia and the Springvale Joint Venture.

This facility will treat the mine water and deliver water to the power station for beneficial reuse. The project aims to enhance the quality of mine water discharged, ensure operational compliance in relation to water outflows and enable continued operations of both the mine and the power station.

The project requirements include:

● Transfer of water from the Springvale Mine to EnergyAustralia’s Mount Piper Power Station
● Treatment and reuse of the mine water, which is to be used as the industrial cooling water for the power station as well as ensuring excess water discharge complies with relevant environmental obligations
● Implementing a brine extraction and crystallisation process that can blend with the waste streams from the Mount Piper Power Station, ensuring both the mine and the power station remain in operations.

Following the construction, Veolia will then be responsible for the operations and ongoing maintenance of the pipeline and treatment facility, over a 15-year period.

“Veolia’s expertise in water treatment as well as our strong presence in mining and infrastructure has given both the Springvale Joint Venture and EnergyAustralia the confidence to award this 15-year water infrastructure contract to Veolia, which is so important to NSW’s power supply and provides an environmental outcome that will guarantee the mine’s future,” said Doug Dean, Managing Director of Veolia Australia and New Zealand.

“This contract confirms the added-value solutions and expertise that our group provides to its energy and mining clients, so that their processes can comply with industry and regulatory standards and can improve the efficiency of their operations.”

While preliminary site activities have already commenced, this contract now allows construction of the Springvale Water Treatment Plant to proceed immediately and will be completed by mid 2019.

The contract is projected to generate a number of jobs in the regional area and approximately 400 million AUD in revenue for Veolia over the coming 17 years.