MINE WATER MANAGEMENT
1. A CIF wastewater treatment solution to treat tailings water to a standard to allow discharge at a gold mining operation in Australia. The technology removes toxic pollutants sulphate, antimony and arsenic from a waste water stream
2. A Clean-iX ® uranium recovery plant to remove low concentrations of uranium from process liquors at a copper / cobalt processing operation in Africa. Clean TeQ is also the 100 % owner of the Syerston project, located in New South Wales, Australia. Syerston is one of the largest and highest grade scandium deposits in the world and one of the highest grade and largest nickel and cobalt deposit outside of Africa.
As ore compositions at mines around the world become more complex and the grades of available resources continue to decline, the amount of tailings per tonne of metal produced is rising. Tailings management is a complex issue that encompasses the technology used to dewater the tailings, materials handling, and water management, as well as the design and risk management of the tailings storage facility( TSF). Mining companies are making significant investments to improve the efficiency and safety of their tailings management processes, driven by issues such as increasing water scarcity, environmental pressures and legislation, and the need to maintain profitability. New technologies and design strategies are needed to address these challenges.
‘ Clean tin’
Strongbow Exploration has engaged Siltbuster Process Solutions( SPS) and Nomenca Ltd to undertake process specification and outline design works for a Water Treatment Plant( WTP) at Strongbow’ s South Crofty project located in Cornwall, UK. Strongbow successfully completed water treatment trials in March 2017 and subsequently, late last year, received a permit from the UK Environment Agency allowing the discharge of up to 25,000 m 3 / d of treated water from the South Crofty mine. Untreated water from historic mining operations( pre-Strongbow) currently flows directly into the Red River. Strongbow’ s new permit allows it to proceed with construction of a mine water treatment facility that will lead to a material improvement in the quality of water discharged.
Richard Williams, Strongbow CEO, stated;“ The receipt of this permit is the culmination of a collaborative effort between the UK Environment Agency, our lead consultants W. S. Atkins and Strongbow. The planned water treatment facility will ensure that the dewatering of the South Crofty mine is conducted in a way that respects and benefits the local environment. As we move towards our final feasibility, we are very hopeful
Water treatment plant designed to treat 25,000 m 3 / d and enable dewatering of the mine workings in the South Crofty project area, Cornwall. SPS was responsible for overseeing the successful water treatment trials at South Crofty. it has extensive experience in the design, construction and operation of mine water treatment plants, including plants at Wheal Jane, Hemerdon, Dawdon( all in the UK) and Strieborná in Slovakia. SPS is responsible for providing the process specifications for the plant and the outline design. It will also provide technical support during the detailed engineering and construction phases and be responsible for commissioning the plant
that our work will lead to the generation of new jobs with the re-opening of the South Crofty‘ clean tin’ mine in this historic and worldclass tin mining district.”
The WTP will use the SPS high density sludge process to recover suspended solids and dissolved metals from the mine water prior to discharge into the Red River. It will oversee the process design and commissioning of the WTP. Nomenca will complete the detailed design, engineering and manage the construction of the WTP.
Design / Build for water plants
In spite of certain advantages, the Design / Build( D / B) project execution method historically has not been widely used for mine water management projects. More recently, mine operators faced with stringent regulatory requirements, cost overruns and a need for speed are taking a fresh look at D / B – and liking what they see.
To understand the advantages of Design / Build, it’ s useful to consider the differences with a traditional Design / Bid / Build contract.
Under the traditional approach, the first step is the conceptual design of the water plant, followed a PFS, then a feasibility study before the project starts. If the project financials are favourable, the project is funded and project execution begins. At this point in a traditional project execution method, an engineering firm develops detailed drawings for the equipment, piping, electricity, construction, building and foundation. These details are then sent to contractors. Bids are solicited and received, the contract awarded and construction begins, continuing until the project is started up and delivered.
Under a D / B contract, the mining company is entrusting all responsibility for project execution to a single source, which performs sufficient engineering to establish a lump-sum bid for the work.
Veolia’ s AnoxKaldnes technology is based on the biofilm principle and is used for biological wastewater treatment. Microorganisms grow on small specially designed plastic carriers that are kept suspended in a reactor
44 International Mining | MARCH 2018