ASSIGNMENT 1
1. What is the purpose of ore reserve and resource estimation? Why are resource and reserve estimates important to the mining industry?
2. What is meant by ore? What is meant by the term waste? How is the distinction between these determined?
3. Describe a typical Magnetic survey? What parameters does the technique measure? What are the steps in using this method? What types of instruments are used? Typically at what stage of an exploration program would this technique be used?
4. One of the key aspects within the JORC code is transparency, what does this mean? What are the other key principles within the JORC code?
5. What geochemical prospecting methods are available?
6. Typically what sizes of core sample in terms of diameter are used in exploration drilling?
7. Define the following terms:
- Range
- Variance
- Standard deviation
- Kurtosis
- Skewness
8. In ore reserve estimation what does the term support mean?
9. What are the rules regarding the reporting of resources and reserves within the JORC code?
10. What is Krige's relationship? What can it be used for?
11. Describe three classical estimation techniques used in mining. Are these techniques accurate? When would it be appropriate to use such techniques?
12. Why are kriging techniques preferable to other estimation methods?
13. Explain what a "competent" person means in the JORC. What qualifications do competent persons require? Can competent person's undertake reserve estimates for more than one type of mineralisation?
14. Determine the mean, the variance and the standard deviation for the grade data set in the following table
|
Iron content % at coordinate values
|
|
|
|
Easting Coordinate (m)
|
|
|
|
0
|
100
|
200
|
300
|
400
|
500
|
600
|
700
|
800
|
900
|
|
Northing coordinate (m)
|
0
|
80
|
78
|
90
|
89
|
90
|
91
|
90
|
87
|
94
|
89
|
|
100
|
77
|
77
|
90
|
88
|
94
|
89
|
89
|
89
|
92
|
96
|
|
200
|
75
|
75
|
91
|
85
|
86
|
87
|
84
|
85
|
89
|
86
|
|
300
|
85
|
64
|
85
|
84
|
85
|
84
|
85
|
85
|
84
|
85
|
|
400
|
90
|
62
|
86
|
84
|
84
|
85
|
86
|
85
|
85
|
85
|
|
500
|
67
|
55
|
86
|
86
|
0
|
86
|
83
|
84
|
86
|
78
|
|
600
|
69
|
50
|
77
|
86
|
0
|
70
|
90
|
81
|
85
|
79
|
|
700
|
70
|
77
|
79
|
83
|
84
|
70
|
77
|
86
|
82
|
80
|
|
800
|
0
|
69
|
78
|
0
|
90
|
65
|
75
|
0
|
81
|
80
|
|
900
|
100
|
69
|
78
|
0
|
90
|
55
|
74
|
0
|
79
|
80
|
15. Define the following:
- The lag
- The geostatistical variance
- The semi-variance
- The semi-variogram
- The sill
- The Nugget effect
- The range
16. Using the method of polygons, determine the average seam thickness and tonnage represented by the following information if coal weighs 0.8 tonne/m3. Note surface is flat and top of coal seam for all boreholes is intersected at the same depth.
17. Determine the inverse of the following Matrix
10 17 10
13 16 12
13 4 7.5
18. Can JORC be applied to undersea mineral deposits?
19. Compare and contrast the JORC code with the US code
20. Why do you need a mathematical expression to represent the experimental variogram?
21. The following function represents an experimental variogram, draw this function and determine the covariance function.
Where C0 = 5, a = 25, C1= 50
22. What type of information concerning the deposit is provided by a variogram?
23. Use the method of polygons to determine the average ore grade and tonnage represented by the information Tables 3, 4 and 5 if the cut-off grade is 2.5% and the ore has a density of 2.8 tonnes/m3. (30 marks)
24. What would be the impact on the answer to question 25 if the cut=off grade is decreased to 2.0%?
ASSIGNMENT 2
1. The table attached shows the gold grade results from a core drilling program undertaken on a regular 100m x 100m grid.
Undertake classical statistics on this data set, calculating the mean, variance and standard deviation.
2. Using the data from question 1, determine experimental variograms in the west to east and north to south directions.
3. Use ordinary kriging to estimate the grade at the location 375m East, 350m North.
Attachment:- Ore Reserve Estimation.rar