Generating cash from tailings: A "green chemistry" approach to extracting more value from the oil sands
Halifax-based Ucore Rare Metals has moved one small step forward in the race to extract rare-earth minerals from oil sands tailings.
Oil sands deposits mined from the Athabasca Basin produces a variety of tailings streams that are mostly comprised of coarse silica sand. Contained within the sand is a sizeable fraction of fines with trace concentrations of iron, vanadium and titanium oxides as well as numerous rare-earth minerals. Although "trace" may not sound like a huge number, when multiplied by millions of tons, that works out to millions of dollars of valuable minerals currently sitting in tailings ponds.
Last July, Ucore partnered up with an unnamed oil sands operator to test its proprietary process. The operator provided a stream of fine tailings from the froth treatment process, where most of the rare-earth minerals and heavy metals are concentrated.
The company says it has successfully leached select metals into various acidic pregnant leach solutions (PLS). The team will now attempt to separate the ions and precipitate each individual metal as an almost-pure carbonate salt.
To separate the numerous ions dissolved in the PLS, Ucore uses a proprietary Superlig®-One process, developed by IBC Advanced Technologies in Utah.
The desired metal ion attaches itself to a metal-selective ligand and silica gel, packed into fixed-bed columns. Once the column is fully loaded, the ions are washed into an aqueous solution using a weak acid, creating a relatively pure eluate solution. The metal ions can be then precipitated into a salt carbonate.
THE SUPERLIG-ONE PROCESS (COURTESY UCORE)
Ucore says it has already successfully separated 16 different rare-earth minerals from one of its deposits in Alaska, producing nitric-acid based solutions at purities greater than 99%.
Conventional solvent extraction of rare-earth minerals generates copious volumes of toxic waste, especially volatile solvents, used to selectively strip the metals out of aqueous solutions. Legacy producers in Australia and the US have been forced to shutdown as environmental laws become more stringent. As a result, China is now the world's only supplier of rare-earth minerals, a pricy commodity in high demand for use in high-tech consumer products.
Ucore isn't the only company hoping to generate cash from the millions of tons of tailings sitting north of Fort McMurray. Calgary-based Titanium Corp has also been working with an unspecified oil sands operator for the past decade to extract various metals, particularly zirconium, from fine tailings. Dubbed "Creating Value from Waste" (CVW™), Titanium Corp's process is designed to be embedded directly into the oil sands operator's process, intercepting tailings before they hit the tailings pond.
Although no one questions the feasibility of extracting more value from the oil sands, making it work economically on a humongous scale is the multi-million dollar question, literally.
UCORE UCORE ATTAINS THREE CLASSES OF PLS FROM ALBERTA OIL SANDS BITUMEN JUN 2017
UCORE UCORE COMMENCES PHASE II OF OIL SANDS PROJECT MAR 2017
UCORE UCORE PARTNERS WITH MAJOR OIL SANDS PRODUCER FOR RECOVERY OF TECHNOLOGY METALS JUL 2016
WHITE PAPER MOLECULAR RECOGNITION TECHNOLOGY: A GREEN CHEMISTRY PROCESS FOR SEPARATION OF INDIVIDUAL RARE EARTH METALS FEB 2016
UCORE SUPERLIG®-ONE PILOT PLANT
UCORE PRESENTATION: MOLECULAR RECOGNITION TECHNOLOGY 2016
TITANIUM CORP AGM PRESENTATION FEB 2017
WHITE PAPER NEW OIL SANDS TECHNOLOGY TO MEET THE CHALLENGES OF CLIMATE CHANGE AND TAILINGS MANAGEMENT SEP 2016