Mining & Mined Caverns - Parsons Brinckerhoff

Feasibility Studies, Geological Assessments, Resource Estimation
APRIL 2012 http://www.pbworld.com/news/publications.aspx
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Figure 4 - Mining Project Life Cycle
tified according to recognised international resource
reporting standards (see “The Relevance of International
Reporting Codes and Their Practical Application
to Resource Estimation”, in this publication);
• Production of a geological model to be used as a basis
for mine design (see “Geological Assessment and
Resource Estimation of Coal Deposits and Their Influence
on Mine Design” in this publication);
• Investigation of the most suitable scale of operation;
• Conducting a technical options study (on all mining,
processing & civil engineering options);
• Following the options study, selection of the best solution
taken through to the definitive feasibility study
(DFS) stage for detailed evaluation;
• Completion of preliminary studies on geotechnical, environmental,
and infrastructure requirements;
• Completion of bench scale metallurgical tests and
preliminary process design;
• Estimation of cost based on factored or comparative
prices; and
• An assessment of the environmental and social fatal
flaws. The environmental impact assessment (EIA)
and the social impact assessment (SIA) process can
be initiated at this stage.
Prefeasibility studies typically have an estimation
accuracy of +/- 20% to 25%. A prefeasibility study
will determine whether or not to proceed with a definitive
feasibility study. These studies are typically carried
out by a third-party mining consultant (such as Parsons
Brinckerhoff). However, if the expertise is available and
independence is not an issue then they can be completed
by in-house teams.
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Definitive Feasibility Study. The definitive feasibility
study, typically based on the most attractive alternative
for the project as previously determined, is the most
detailed and should remove all significant uncertainties
and present the relevant information with back up material
in a concise and accessible way. The definitive feasibility
study has several objectives:
• To demonstrate with reasonable confidence that the
project can be constructed and operated in a technically
sound and economically viable manner;
• To provide a basis for detailed design and construction;
• To enable finance for the project to be raised from
banks or other sources; and
• To provide the basis for permitting and regulatory approvals.
The definitive feasibility study typically has an
estimation accuracy of +/-10 to 15%.
The Importance of Getting it Right
The early stages of the feasibility study process are important
– the scoping and prefeasibility study levels are
when design options can be flexed and tested. It is acceptable
for scoping studies to be based on very limited
information or speculative assumptions in the absence
of hard data. The study is directed at the potential of
the property and the study should err on the side of
optimism – getting it wrong at this stage will not be as
costly as rejecting an otherwise economically viable project
due to being too risk adverse.
Influence on the outcome diminishes once the
project has reached the definitive feasibility level, the
options and design should be more or less fixed, with