The Canadian gold mining industry is highly-regulated, as it should be — it’s essential to protect the environment, and it is a leading example for the rest of the world. However, several current best are decades old; others are recent and aspire to be industry-wide best practices. We’ve compiled these best practices into a list that will be useful for everyone involved in mine water treatment, no matter what kind of role you have.
Tip #1: Consider Context When Using New Assets
Water management and treatment strategies are considered when designing new and updating existing assets. There are jurisdictions where passive or semi-passive water treatment methods are used instead of active treatment to conserve money and improve sustainability.
Tip #2: Employ Methods Beneficial to the Site
Water treatment for Canadian gold mining has evolved in recent years. Gone are the days of out-of-the-box, ‘cookie-cutter’ water treatment systems that treat every mine the same. We now know that each mine is unique in its water quality and needs a customized water treatment system. Although traditional turnkey water treatment systems are still widely used, they can now be integrated into a more comprehensive strategy.
Tip #3: Protect the Water from Contaminants
While this tip seems like common sense, it can be challenging to implement for Canadian gold mining. Well-known approaches include diversion structures, contouring, and covers. Preventive methods include optimizing the design and progressively applying masks and soil during operations.
More recently, the aspect of prevent-rather-than-treat has expanded to include in situ (in place) source control measures. Biogeochemical reactions stabilize the oxidation of sulphide minerals and maintain neutral pH. Examples of well-known applications of this principle include adding lime, which buffers pH and prevents oxygen from reaching water or rock, creating an anaerobic environment.
This can also be applied to tailings ponds or mine pits as an in situ source control measure. A more modern example is to utilize redox buffering in tailings and ponds. Redox softening processes enable biogeochemical interactions with sulphide minerals to prevent further oxidation of acid mine drainage (AMD).
Tip #4: Remember the Mine Life Cycle
Water quality and quantity will fluctuate throughout Canadian gold mining. Fortunately, many of these changes can be predicted, and plans can be made to account for them. Due to extensive earth-moving activities, the construction and early closure stages cause higher turbidity and solids in the water. Also, construction activities increase nitrogen species such as ammonia, nitrate, and nitrite. This water eventually converts into nitrate when no new material is added.
Meanwhile, metals and metalloids can increase through oxidation over time. The source and location of water also change throughout the life of a mine (e.g., dewatering, milling, and metallurgical processes) as sources are depleted or as new applications arise. Mining engineers must consider these when formulating a water treatment plan.
Tip #5: Respectfully Approach the Constituents
Historically, water treatment has focused on removing contaminants; however, this leads to secondary waste streams, such as sludges and brines, which must be considered when designing a site-wide water management strategy.
For example, if sludge or brine is placed into an area containing drinking water, this must be regarded for future water treatment plans. If more advanced semi-passive or in situ treatment systems are used, then the stability of the constituents and minerals entrained within the system must also be considered.
Be Part of Environmentally-Conscious Canadian Gold Mining
These five tips will help your project extract gold with a minimal negative impact on surrounding habitats. As the world returns to normal since COVID restrictions are becoming less prohibitive, we must move forward with earth-minded strategies to preserve our resources and create a safer planet for future generations.
It’s time to be part of a better approach to Canadian gold mining. Speak with Newfoundland Gold today and join their advocacy!