The 2007 Class Project

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Transcript The 2007 Class Project

The 2007 Class Project
©2007 Dr. B. C. Paul
The 2007 Project
• A copper/moly porphyry deposit located near
Eureka Utah
– Ie (hard rock deposit)
• Deposit is close enough to surface to be surface
mined – open pit
– Will be first year for using powerful mine planning
software [Minesight]
• During any week we will have lectures on
multiple subjects – need to be learning several
things at once
How Weeks are Set Up
• One set lectures on Software
• One set of lectures on procedures for
• One set of lectures on reporting or
estimating or economic analysis
• Each week will have one or more tasks –
often in several of the areas that will be
spot checked the following week.
– (no the work load for this course is not fair)
How Do You Design a Hardrock
Open Pit Metal Mine?
• Need basic feed data
– Geologic exploration data for developing a
reserves model
– Price data to enable one to bracket likely
selling price ranges for product (Cu is usually
between 60 cents and $4/lb)
– Need to have basic cost data for mining,
processing ore and refining product
– A lot of our first efforts will deal with compiling
this fundamental feed data
The Hocus Pocus Dilemma
• Mine costs depend on equipment size, type, and
mining rate
• Bench Heights depend on equipment size
• Exploration composite intervals depend on
bench heights
• Block sizes depend on composite intervals
• Reserves depend on costs and block models
• Proper Equipment size and mine rate depends
on reserves
Breaking Out of the Loop
• Basic feed data allows one to make initial
guesses of parameters that will usually be
pretty good once things get going.
Overview Continuation
• Drill Hole Data is fed into interpolation and
geologic models to project ore and rock type and
grade onto a 3 dimension grid of blocks called a
block model
• Cost Estimates are used to covert each blocks
ore grade and rock type into an economic value.
• Computer algorithms scan the block model for
the set of blocks that yields the greatest total
– Called the Ultimate Pit
– Ore removed is then assessed for grade and quantity
to produce a grade and tonnage relationship
• Ore Reserves are used to estimate mine life, production
rate, check equipment type
• Manipulation of prices or costs are then used to get
routine to pit smaller richer pits
– These pits then used to form stages starting with richest ore and
then moving to limits
• Grade Tonnage Curves are then produced for each
• An optimization routine picks a dynamically changing
Cut-off grade for each stage
• Equipment and tonnages are then fixed throughout life of
• Costs are determined and economics evaluated.
Starting Your Work
• Researching Metal
– USGS has site that
gives inflation adjusted
prices by metal
Continuing Work
Select Copper and Excel Format
Price Data to 2004
More Recent Data
Adding Data
Add the Recent Price Data
Need to Get All Values to Common
1998 = 162.3
2006 = 200.6
Ratio is
200.6/162.3 = 1.236
Multiply all prices in
1998 by 1.236 to get
2006 data
Get on a Common Basis
Copper Price
Copper/lb $2006
Copper/lb $2006
Putting in SPSS
The Data