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Modeling Blast Movement for Grade Control
Edward Isaaks Robert Barr Onie Handayani
Ore Control at Boddington
Post Blast Dig Lines?
Proposed Solution Simulate the blast movement of each sub-block conditional to blast movement data.
Available Data
The Ore Control Block Model
Blast Movement Monitoring (BMM) Data • 1,515 BMM observations • 35 variables per observation
Classification Analysis
1515
South Pit North Pit
An, Di An, Di, Do An, Di, Do Di, Do
Echelon Center Lift
Group Statistics
Group 3 - horizontal movement versus depth from top
Post Blast Surface Topography
Blast Initiation Sequence
Modeling Blast Movement
Ore Control Model (OCM) Voxels Pre Blast OCM cross section
Post Blast OCM cross section
Assign a Distribution of Horizontal Movements to each Pre-Blast Voxel
N(6,3)
N(16,4)
N(8,3)
Assign Movement Direction to each Pre-Blast Voxel and Post-Blast Grid Node
Add a random component to each pre-blast voxel direction at time of simulation
Simulate Blast Movement 1. Randomly select a pre-blast voxel. 2. Draw a random distance from the distribution of
voxel horizontal movements. 3. Add a random component to the voxel movement
direction. 4. Calculate the destination grid node in the post-
blast enevelope. 5. Move the pre-blast voxel to the post-blast grid
node if vacant. 6. Continue steps 1 – 5 until all post blast grid nodes
are occupied.
Simulate blast movement
Results
Post-Blast Tonnes = Pre-Blast Tonnes
Post Blast-Volume = 1.38 x Pre-Blast Volume
Post-Blast Grade = Pre-Blast Grade
Post-Blast Model Topo = Surveyed Post-Blast Topo
Histogram of 257,100 Simulated Horizontal Movement Vectors
Simulated Horizontal Movement Vectors Versus Depth-From-Top
Application to Grade Control
Pre-Blast Dig Lines Post-Blast Dig Lines
Tonnes
Grade
Ounces Au
Recoverable Ounces Au
Recoverable pre-blast oz Au = 14,241
Recoverable post-blast oz Au = 14,169
Loss = 72 oz Au
Future Work
• Validation of the model. • Add control parameters to the simulation algorithm. • Additional work on characterizing the random directional component. • Development of a software product.
Thank you
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