Estimation vs. Simulation

Question 1

Name three (3) shortcomings of the Conventional models (Estimation)

Answer 1

1. DO NOT account for uncertainty. Estimation methods try to approximate some average grade value… not the actual one
2. DO. NOT account for local grade variability
3. Smoothing/misrepresentation from estimatino on G-T curves has adverse effects on mine plan,design, production forecasts, financial evals, prod. expectations, investments…

Question 2

Explain this photo

Answer 2

:)

Question 2

Explain this photo

Answer 2

:)

Question 3

Discuss this graph

Answer 3

Estimated models (Red) Overestimates low-grades AND Underestimated high-grades, comparatively to simulated models.

Question 4

Why is Uncertainty ‘not a bad thing’ ?

Answer 4

You can take advantage of uncertainty. Your strategic investments will be sheltered from its adverse effects while remaining exposed to its upside potential. Uncertainty will create opportunities and value. 

Question 5

Develop on this graph

Answer 5

Question 6

Name four (4) results of Stochastic mine planning

Answer 6

1. Lower risk in meeting forecasts
2. Higher value for less risk
3. Larger ultimate pit limits
4. More metal

Question 7

Case Study: Fimiston Open Pit Mine, Western Australia Orre Boundaries

What are the conclusions?

Answer 7

• Stochastic has higher tonnages for 90% and 10% compared to deterministic
• and

Question 8

Discuss the general non-linearity of mining ‘transfer functions’

Answer 8

An average type of block model may not provide an average map of the space of response uncertainty; and Nature Does not Know about Distributions Deposit Attributes DO NOT Follow any Given Distribution Model 

Question 9

Discuss the depicted graph

Answer 9

:)

Question 10

Name two (2) characteristics of Estimation Method (Chap 10)

Answer 10

1. An unbiased estimate of a point 𝑍 (𝐱) or volume 𝑍𝑉( 𝐱 ), centred at location 𝐱 ∈ 𝒟, where 𝒟 is the geological domain.  
2. Estimates smooth-out the low- and high- grades; as a result, they are unable to reproduce the grade distribution and variogram of the input data.  

Question 11

Name two (2) characteristics of Simulation Method (Chap 10)

Answer 11

1. Generate a set of possibilities, conditioned to existing data (drillholes, blastholes, etc.) that, as a group, quantify the uncertainty in the deposit.  
2. More importantly, we wish to reproduce the statistics of the input data (mean, variance, etc.), along with all spatial relationships between points. 

Question 12

Remember this shtuff

Answer 12

Question 13

Remember this shtuff

Answer 13