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
design
• 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
worth
– Called the Ultimate Pit
– Ore removed is then assessed for grade and quantity
to produce a grade and tonnage relationship
Continuing
• 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
stage
• An optimization routine picks a dynamically changing
Cut-off grade for each stage
• Equipment and tonnages are then fixed throughout life of
mine
• Costs are determined and economics evaluated.
Starting Your Work
• Researching Metal
Prices
– USGS has site that
gives inflation adjusted
prices by metal
Continuing Work
Select Copper and Excel Format
Price Data to 2004
More Recent Data
(1.5+1.8)/2=1.65
Adding Data
Add the Recent Price Data
Need to Get All Values to Common
Basis
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
6.000
5.000
3.000
Copper/lb $2006
2.000
1.000
Year
2000
1990
1980
1970
1960
1950
1940
1930
1920
1910
0.000
1900
$/lb
4.000
Putting in SPSS
The Data