WATER MANAGEMENT
continuously by Frontier Water field engineer staff to maintain high rate selenium reduction to > 95 % removal .
E2metrix and electro treatment
For an insight into one of the growing breed of up and coming new technology companies in mine water treatment , IM spoke to Tom Whitton , Vice President , Business Development at E2metrix , a Sherbrooke , Quebec based company which uses electro technology and has numerous patents for its flagship ECOTHOR-EC™ process that utilises electrocoagulation to treat and eliminate complex organics , total suspended solids , heavy metals , emulsified oils , phosphates , ammonia , other contaminants from water . It essentially uses electrolysis reactors that can be configured in different ways to treat different contaminants . They are cylindrical and can be plugged together in series in different configurations depending on the contaminant . In mining it also offers ECOTHOR-AOP™ for the treatment and removal of complex organics and / or ammonia using advanced oxidation electrolysis , with zero waste , again using reactors .
The company has been active since 2011 especially in leachate and groundwater projects but is relatively new to mining but Whitton says the modularity element lends itself well to mining .“ The type of contaminants we are looking at with ECOTHOR in mining include ammonia nitrogen from blasting agent residues in mine water or in tailing pond runoff or process water from gold mining from residual cyanide . It can also remove metals like nickel , copper , zinc , manganese , arsenic and selenium . Cyanide itself can be removed as well as suspended solids and flocculant hydrocarbons . But its one thing to have the tech , it also needs to be an economical solution .”
In Canada regulations on ammonia nitrogen release are getting tougher . The ECOTHOR AOP approach has already been proven at lab and pilot scale for ammonia removal from mine water and
E2metrix is now working with Osisko Mining at their Windfall world-class gold project located in the Eeyou-Itschee James Bay territory of Quebec . It is an advanced exploration camp where a lot of infill drilling is currently being carried out as well as blasting for bulk samples and exploration ramp development . The mine could be in production as early as 2024 . E2metrix just started up its mobile water treatment unit at the site to treat water and is looking at different ways to best utilise it , mainly for ammonia removal . The mobile aspect means Osisko will be able to deploy the unit at other projects if required .
So what is the ECOTHOR selling point ? “ From a cost standpoint , our sweet spot versus other technologies is in lower to mid-range flow rates up to 10,000 m 3 per day , coupled with the modular aspect of the reactors . We are mainly competing with Moving Bed Biofilm Reactor ( MBBR ) technology in our space but that ’ s a biological process not well suited to the cold climate extremes seen in Canada , where that approach would require constant heating to keep the bacteria alive . Our process is not affected by climate beyond preventing frozen pipes , the electrolysis is just turned on or off . Another approach we come up against is the use of zeolites , but then you have to deal with the zeolite after it has absorbed the contaminant . With ECOTHOR there is no residual material .”
There is also really good potential for ECOTHOR to deal with multiple contaminants at the same time such as the suspended solids and metals in water from thickening operations . Here ECOTHOR-EC is a good fit .
Overall , unlike some other companies that are integrating different technologies into an overall water treatment solution – E2metrix is offering one tool for mining that can be used on its own in a smaller installation but can also be incorporated into a larger plant , such as by an engineering company , an integrator or by the operator themselves .
Osmoflo on economical brine concentration in desal
Osmoflo is a global desalination and water treatment company , located across Australia , the Middle East , India and Asia . The company told IM that sustainable reverse osmosis ( RO ) desalination requires continuous “ cross flow ” across the surface of spiral wound membranes to try and prevent scaling and fouling building up on the surface of the membrane . If the layer of foulants and scale becomes too thick , it is harder to drive the fresh water through , leading to feedwater pressure increase and lower permeate flow .
Cross flow also helps reduce “ concentration polarisation ” which is the build-up of ionic constituents against the polyamide layer on the surface of the RO membranes which allows the fresh water to be pushed through but provides a barrier to salts .
“ Generally , maintaining high cross flow means that recovery ( the ratio of permeate to feed usually expressed as a percentage ) is lower . Low recovery means that there are larger amounts of concentrate ( brine ) to dispose of which , for inland plants , usually means evaporation in large shallow double lined ponds or further concentration in expensive and energy intensive proprietary thermal crystallisers .”
Osmoflo has developed a patented brine
A mobile , modular ECOTHOR water treatment solution from E2metrix
squeezer ( OBS ) technology to increase recovery from RO plants at an affordable cost and is provided as a service by Osmoflo . The ‘ Brine Squeezer ’ is an innovative reverse osmosis process that combines known membrane principles to manage fouling and scaling that are risks to sustainable operation in conventional RO plant .
These include use of proprietary membranes , use of high cross flow velocities independent of feed flow and operation at concentrations well in excess of normal saturation limits . It also includes effective use of antiscalants and innovative cleaning to remove foulants and scaling by effective use of chemicals , high temperature and osmosis . Advanced automation and machine learning continuously adjust operating parameters and sequencing automated membrane cleaning .
A number of benefits have been demonstrated over conventional technologies such as ultrahigh-pressure RO . These include : n Achieve overall ultra-high recoveries up to 95 % n Minimisation of brine disposal costs n Lower cost compared to alternative technologies n High level of automation requiring less operator intervention Due to the individual chemical make-up of each water , a pilot trial is required to determine the most appropriate key design and operating parameters , antiscalants , cleaning chemicals and expected cleaning frequency for each specific project .
Osmoflo says it has conducted successful OBS trials at six different industrial sites including acid mine drainage in Queensland . Full scale
Osmoflo ’ s Brine Squeezer technology installed at a uranium mine in NT , Australia
44 International Mining | MARCH 2021