is there a role for lerchs-grossman optimization in industrialminerals and aggregates mine planning?
DESCRIPTION
Presentation given by Dr. Kwame Awuah-Offei at the 2014 SME Annual Meeting in Salt Lake, UT.TRANSCRIPT
![Page 1: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/1.jpg)
Is There a Role for Lerchs-Grossman Optimization in Industrial
Minerals and Aggregates Mine Planning?
Kwame Awuah-OffeiAssociate Professor
Missouri University of Sc. & Tech
![Page 2: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/2.jpg)
Pit Optimization
• Optimization problem that selects the blocks to be mined to maximize pit value while respecting all constraints
• Two most popular methods:– Floating cone
– Lerchs-Grossman (LG)
2
![Page 3: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/3.jpg)
Objective
1. To discuss the challenges and benefits of implementing LG optimization in industrial minerals and aggregates (IM&A)
2. Make recommendations for when it is useful
3
![Page 4: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/4.jpg)
Challenges in IM&A
• Lack of resources to engage in detailed strategic mine planning
• Long mine lives make it difficult to estimate costs and prices
• Difficulty estimating value as a function of grade
• Multiple products with complicated value relationships
4
![Page 5: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/5.jpg)
Benefits in Mine Planning
• Establish economic boundaries of pit (including surface/underground boundary)
• Determine optimal mining phases
• Evaluate effect of pricing policy on reserves
• To determine optimal location of facilities (waste dumps, plant etc.)
5
![Page 6: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/6.jpg)
Sand & Gravel Case Study
6
![Page 7: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/7.jpg)
Objectives of the Optimization
• To define economic horizons of the ultimate pit
• To determine pricing strategy
7
![Page 8: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/8.jpg)
Input Data
8
Parameter Value
Average Sales Price $11.97/ton
Ore Cost $5.94/ton
Stripping Cost $1.70/yd3
Density of Material 0.06 tons/ft3
Slope 1.5:1
Grade 1-wash loss
Discount Values (%) -10, 0, 10, & 20
![Page 9: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/9.jpg)
Default Price – 0% Discount
9
![Page 10: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/10.jpg)
Price Discount = 10%
10
![Page 11: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/11.jpg)
Price Discount = 20%
11
![Page 12: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/12.jpg)
Price Discount = -10%
12
![Page 13: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/13.jpg)
Price-Reserve CurvePrive vs. Reserve Curve
0
10
20
30
40
50
60
70
$9.00 $9.50 $10.00 $10.50 $11.00 $11.50 $12.00 $12.50 $13.00 $13.50
Average Sales Price ($/ton)
Rese
rv
e (
mil
lio
n t
on
s)
13
![Page 14: Is There a Role for Lerchs-Grossman Optimization in IndustrialMinerals and Aggregates Mine Planning?](https://reader036.vdocument.in/reader036/viewer/2022082223/5594dd181a28ab94328b45ca/html5/thumbnails/14.jpg)
Summary & Recommendations
• In industrial minerals & aggregates pit optimization might still be useful in strategic mine planning
• Using qualified consultants for training or strategic mine planning can address lack of resources
• Clearly define what you intend to get out of this step
• IM&A experience is crucial to properly define value (iterations may be necessary)
14