Specific challenges and opportunities - Salts.
The management of salts is critical in mining operations. Naturally occurring salts in the oil sands ore are released upon processing and end up in tailings ponds.
Salts are also present in mine depressurization water and river water, all of which are used in oil sands operations. As operators strive to increase the proportion of water that is recycled on site, salt concentrations will increase. That poses new challenges which might include:
- Making it more difficult to extract bitumen from the ore and meet regulatory requirements for bitumen recovery efficiency.
- Reducing the reliability and efficiency of process equipment through corrosion.
- Increasing the levels of salts in tailings and adjoining areas to levels higher than normally found in boreal forest habitats, making the reclamation process more challenging.
There are several COSIA projects related to effectively managing salts on mine sites. A few are noted below:
- Salt Management Study (Teck with all COSIA Members)
Assesses the environmental effects of allowing salt to accumulate in recycle circuits during mining versus reducing the salt concentration of recycled water during mining operations.
- Treatment of Depressurization Water (Canadian Natural)
Involves pilot tests for treating and reusing depressurization and tailings water in operations. Technologies include reverse osmosis, evaporator, crystalliser, saltmaker and thermionic technologies.