Tailing Dams Technology Review

Updated: Mar 9



This blog’s picture is that of an aerial view of the Moose River Touquoy Mine tailings dam impoundment or tailings management facility (TMF). The photo is courtesy of Raymond Plourde of the Ecology Action Centre. With this visual and the following aerial video of the Touquoy mine, we may now get an enhanced image of what we could expect for the proposed Cochrane Hill tailings management facility and open pit mine.


Aerial views of the Moose River Touquoy Gold Mine and Tailings Dams – This video was assembled from amazing aerial pictures captured by Raymond Plourde of the Ecology Action Centre – Remember the mine is only in the second year of operation. The little dots in the open pit mine are the large earth moving trucks. You will require a media player to view.

This is an interactive blog that allows you to listen to a series of very informative podcasts. As you listen to the podcasts, think about what you hear can facilitate your response to the draft environmental impact statement(EIS) for the project. What information on the tailings dam may be missing from the draft EIS? If the project is approved, what conditions of environmental and industrial approvals should be attached by the regulator.


There are a series of five (5) Podcasts from the publication “Mining Journal” on “Tailings and Water Management” This is a great series to enhance your understanding of tailings dams. Following each link is a summary of critical aspects of the particular podcast that relate to the proposed tailings dam at Cochrane Hill.


Tailings and Water Management #1- Establishment of an international working group given the recent Brazil Tailings Dam Failures by Vale. Risk to Mining Investors.


Tailings and Water Management #2 – Reaction of Investors – Does mining meet socially responsible investment criteria. Questioning the adequacy of regulations, of enforcement, and the availability of sufficient fiscal resources for regulatory bodies.


It’s not regulation that fails, it’s [the industry] as engineers and operators #3- Site Selection is critical in the design of a tailings dam as is the technology used to dispose of tailings; slurry versus dry. What will likely be the source of material for the dam at Cochrane Hill? It touches upon the fiscal impact of a short term life of mine(as is the case of Cochrane Hill) on tailings dam design and on the impact of an extension of the ore resource on the initial design of the tailings dam.


They can never absolve themselves of oversight and governing of the contract #4 Legal aspects of tailings dam facilities. Allocation of risks associated with tailings dams design, construction and operation. Engineer of Record (EOR) rears its head again.


We foresee a future where everyone moves to real-time TSF monitoring #5 developing innovative new mining technology, utilizing Inmarsat’s world leading satellite connectivity services. This includes the launch of a best available technology tailings monitoring and management system in March, 2019. Currently, monitoring instruments such as piezometers at many operations are read manually year-round, at varying intervals. Data is taken, filed and shared using disparate platforms and networks, creating datasets over varied date ranges and consistencies, which are made available on a delayed basis to limited individuals. FYI, it was mentioned at the Atlantic Golds Tailings Dam open house that piezometers are being utilized at the Moose River Touquoy Mine as a tool to monitor the dam.


Mining Journal Tailings Review – Investors and Technology to Drive Cultural Shift – This is a 16-page review of tailings dam technology, some of the information is a repeat of blog material, however the more you read the more one may understand tailings dams. Some excerpts from the article ………:


The first issue investigators are likely to run up against is that tailings storage facility (TSF) practices have seen only incremental change for the past 20-30 years. “Despite the introduction of thickened discharge technology and filtration, conventional thickened- slurry tailings deposition, mainly to valley-surface TSFs, continues to be the most common method of tailings management,” our more technical colleagues from sister title Mining Magazine told us. Management continues to focus on a “degree of thickening … in the processing plant” to allow transport as a slurry using “robust and relatively inexpensive centrifugal pumps”. Thickened or paste tailings that need expensive and input-sensitive positive displacement pumps” remain rare. Filtration of tailings, meanwhile, is mainly restricted to water- sensitive regions where water recovery for use in the plant provides an economic argument.

Central for the TSF-specific challenge has been the escalating scale of mining operations and the ore-to-waste ratio. As miners have naturally over the decades prioritised high-grade, low-cost deposits, the grades of modern mines are low. Meanwhile, the population density of the world is up 140% since 1960, driving the growing demand profile. This means bigger holes with a greater proportion of waste finding its way to TSFs.


“We get a range of questions from investors and they are becoming more technical,” he told Mining Journal.

“Investors are doing specific reading on tailings and are using relevant language. Some are further along the road to understanding the sort of cultural shift needed than miners are.” Martindale said investors basically wanted to know if the companies to which they were exposed had higher-risk TSFs and whether all TSFs were being maintained adequately. If the second part of that equation was questionable, the investment was likely to come under severe scrutiny.


“Social, environmental and governance considerations are no longer seen as boxes to tick but as issues that make or break assets and investments,”. “You can have a great resource and a pro- business administration, but if your community is not on your side then whatever you have is worthless – if your investment is stalled by 10 years then chances are you’ve lost your profit.

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stmarysriver@ns.sympatico.ca

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