Mineral resources are finite, meaning that the lifespan of any mine
is limited. The longevity of operations can also vary considerably. For
example, while a copper mine may last for up to 70 years, sources of
some resources - such as platinum or iron ore - can have a lifespan
lasting as little as a decade (or less).
The eventual closure of any mining operation is hence inevitable, and
can potentially have a negative effect on host communities -
particularly those that are heavily reliant on mining for jobs and
livelihoods - as well as adverse environmental impacts.
Through effective decision-making, however, mining and metals
companies can more easily and sustainably transition through the
different phases of a mine`s lifecycle leading up to its eventual
closure. Where mine closure is concerned, ‘mining with principles` means
adopting processes and decision-making procedures that support
sustainable development throughout the entire lifespan of an operation -
from initial planning to design, operation and eventual closure of the
site.
The closure in itself is a multi-stage process, taking in:
• Shutdown;
• Decommissioning;
• Remediation and clean-up;
• Land reclamation, restoration and rehabilitation; and
• Long-term monitoring of the site.
Once a mine`s mineral deposits are exhausted, mining companies are
responsible for rehabilitating affected land and water courses. This
means returning disturbed land to a stable and productive condition,
paying particular attention to environmental concerns such as the
preservation of biodiversity and the restoration of pre-existing
ecosystems. Mining companies are also required to work with local
communities to offset any potentially negative social and economic
impacts of site closure.
Planning for closure is therefore a core business practice for
responsible mining companies, and is ideally considered during the
design phase of a new mine. Early stakeholder engagement measures are
also essential, as they make closing a mine in a sustainable manner so
much easier. Experience shows that closure is as much a managerial and
stakeholder engagement issue as it is a technical one, requiring the
continual testing of assumptions and recommendations, so as to match
evolving conditions and expectations.
For all of these reasons, Principle 2 of ICMM`s Sustainable
Development Framework commits its member companies to fully integrate
sustainable development into their corporate strategies and
decision-making processes.
ICMM has also worked with its partners to develop a mine closure
toolkit, designed to help companies plan for and effective, efficient
and integrated shutdown that minimises risk of any potential damage to
either local communities or ecosystems. This toolkit aims to support
mine operators in identifying potential problems as early as possible,
as well as in minimising the risk of regulatory non-compliance.
ICMM says its members Rio Tinto and Barrick can both provide examples
of sustainable mine closure, with Rio Tinto`s work in successfully
decommissioning and redeveloping the former Sabart aluminium plant in
France being a great illustration of how effective planning can produce
positive outcomes.
By the 1990s, the relatively small Sabart operation had become
uncompetitive, and hence it was closed - with the mine`s then-owners
abandoning the six-hectare site. In the past few years, Rio Tinto (which
inherited the site) has not only collaborated with the local community
in planning for the site`s future, but also invested millions in a
decommissioning and rehabilitation programme - comprising soil
decontamination, the removal of 10,000t of contaminated materials
(including asbestos), and the demolition of large structures and
foundations that were still present on the legacy site.
As of 2017, the decommissioning work was complete, with the land
being sold to the local city council at a discounted price and plans in
place to transform the site into a new recreational area and business
park - boosting the town`s economy while creating further employment
opportunities.
Following the 2008 closure of its Eskay Creek gold mine in British
Columbia, Canada, operator Barrick embarked on a rehabilitation and
restoration project to return the environment to a stable condition.
This comprised earthwork, re-vegetation and re-contouring of the slopes
around the former mine, along with long-term water management plans.
The Eskay Creek mine, like many others, had contained sulphur-based
rocks and tailings that, if left exposed, could potentially generate
harmful acidic water. The key to preventing this was to starve the rocks
of oxygen - so Barrick chose to safely store the waste rock deep
underwater, monitoring the site for water quality on a quarterly basis.