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Introduction > Mine Life Cycle
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The Mine Life Cycle
The life of a mine is conceptualized in roughly five stages, from exploration
through closure and reclamation.
Exploration
The exploration stage involves initial evaluations of the location, quality, thickness and
continuity of the deposit. There’s an eye toward eventually determining whether the deposit
will be technically and economically feasible to mine, and toward identifying possible
development scenarios.
The exploration stage involves drilling test wells and testing core samples, as well as
seismic studies and other types of assessments. Mineral
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Exploratory Drilling
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rights and surface rights are negotiated.
Exploration permits are obtained from the Arizona Oil and Gas Conservation Commission.
For exploration on state trust land, they are also required by Arizona State
Land Department. For exploration on BLM land, permits are required from the Bureau of Land
Management.
This stage results in production of a technical report on the potash resource, developed
according to a standard set by the Canadian Institute of Mining called the “National
Instruments 43-101” or NI 43-101.
Planning & Permitting
The probability of a project progressing beyond the exploration stage is small, but if it
passes that hurdle, it moves into the feasibility assessment, planning and mine permitting
stage. Economic analyses are completed, as are engineering feasibility studies and
environmental assessments. Documents that are often produced include a preliminary economic
assessment, pre-feasibility report, feasibility report, a mine plan of operations,
and a reclamation and closure plan along with technical engineering and design
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Drill Site After Drilling Completed
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specifications.
Projects go through regulatory processes in pursuit of permits and authorization to proceed
under specified terms and conditions. Plans are reviewed by state agencies, and possibly
federal agencies, and public meetings and hearings may be held. Whereas many types of industrial
projects require special use permits from the county, as well as building permits, mines are
exempt in Arizona by state statute.
The processes involved in permitting mines in Arizona are described in the
Arizona Mining Permitting Guide.
See also Addressing Impacts: Permitting.
Construction
After receiving necessary permits, and completing planning and receiving approvals from backers,
a project enters the construction stage, which may last for years and continue into the early
years of operation.
Like any major civil engineering and construction effort, there are many phases and people with a variety of
skills serve in different roles at various times. At this stage of mine development, there
are often opportunities for local suppliers and workers.
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Mosaic Potash, Carlsbad, New Mexico
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The major activities involved in constructing the ore-extraction facilities naturally differ
between underground and solution mines. For both
types of mines,
construction of surface facilities includes building administrative, warehouse, maintenance
and storage buildings, the mill, load-out facilities and the storage/rail yard, and completing
infrastructure for power, gas and water supplies, roads and a rail spur.
Operations
During operations, the major activities involve extraction of ore, transportation of ore to
refining facilities, refining in a mill and processing to
produce mineral fertilizer, handling of tailings and other waste, and shipment of the finished
product. In the case of solution mines, the ore is dissolved in the ore body and then extracted
in liquid form, then either evaporated in a solar evaporation pond or recrystallized at the mill.
The operations stage may continue for years or decades, with changes over time due to
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Mosaic Potash Pond, Carlsbad, New Mexico
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workforce or environmental issues, expansion or changes in ownership. For solution mines, there are a
series of transitions between phases in the operational life of the mine, as the caverns are
completed and the mine shifts to extraction without increasing cavern size.
Closure & Reclamation
Ore of sufficient quality for economic extraction may support mining for decades, but
eventually, either due to exhaustion of the resource, changes in the market, or
operational problems, the mine is closed and the area is reclaimed. In some cases, an old
underground mine may be closed and converted to a solution mine before the mine is
eventually closed again.
Closure can be a particularly stressful time for individuals and local communities that face
the loss of jobs and economic benefits. Planning and securing funding for closure and
reclamation
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Intrepid Potash North Facility
Carlsbad, New Mexico
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are critical parts of the planning process, addressed during permitting. Often, a
major activity during reclamation is removal of the salt tailings pile and rehabilitation of
the tailings management area.
For More Information
Environmental Permitting Requirements - Proposed Potash Mining in the Holbrook Basin,
Arizona Department of Environmental Quality Information Sheet.
Potash Capacity Development Overview, by PotashCorp (Canada)
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