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 get2006 data

Get on a Common Basis

Copper Price

Copper/lb $2006

0.000

1.000

2.000

3.000

4.000

5.000

6.000

1900

1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

Year

$/lb Copper/lb $2006

Putting in SPSS

The Data