Chapter 6 - Feasibility Studies
Number Topic Rule of Thumb
6.01 Cost The cost of a detailed feasibility study will be in a range from ½% to 1½% of the total estimated project cost.  Source: Frohling and Lewis
6.02 Cost The cost of a detailed or “bankable” feasibility study is typically in the range of 2% to 5% of the project, if the costs of additional (in-fill) drilling, assaying, metallurgical testing, geotechnical investigations, environmental scrutiny, etc. are added to the direct and indirect costs of the study itself.  Source: R. S. Frew
6.03 Time The definitive feasibility study for a small, simple mining project may be completed in as little as 6-8 weeks.  For a medium-sized venture it may take 3-4 months, and a large mining project will take 6-9 months.  A world-scale mining project may require more than one year.  Source: Bob Rappolt and Mike Gray
6.04 Accuracy ±15% accuracy of capital costs in a detailed feasibility study may be obtained with 15% of the formal engineering completed; ±10% accuracy with 50% completed and ±5% accuracy may be obtained only after formal engineering is complete.  Source: Frohling, Lewis and others
6.05 Production Rate The production rate (scale of operations) proposed in a feasibility study should be approximately equal to that given by applying Taylor’s Law.  (Refer to Section 6.6)
6.06 Production Rate Annual production should be one-third of the tons per vertical foot times 365 days in a year for a steeply dipping ore body.  Source: Ron Cook
6.07 Production Rate In the case of an orebody that is more or less vertical, the daily tonnage rate may approximate 15% of the tonnes indicated or developed per vertical meter of depth.  Source: Northern Miner Press
6.08 Production Rate At many mines, the annual production is equal to 30 vertical meters of ore.  Others vary between 25 and 40 meters.  Source: Wayne Romer
6.09 Production Rate For a steeply dipping orebody, annual production should not exceed 30 to 40 meters of mine depth.  Source: Robin Oram
6.10 Production Rate For a steeply dipping ore body, the production rate should not exceed 60 meters (vertical) for a small mine.  At mines producing over two million tons per year, 30-35 meters per year represents observed practice.  Source: McCarthy and Tatman
6.11 Development Preproduction development should be six months ahead of production.  Source: METSInfo
6.12 Development Six months of production ore should be accessible at all times to ensure stope scheduling and blending.  Source: Kirk Rodgers
 
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