Describe the process of exploration project to mining

Question

NB: List and justify all your choices and assumptions.

1.    Describe the process of exploration project to mining operation with reference to the ore resource/reserve estimation process.

2.    What is meant by ore? What is meant by the term waste? What is proto ore?

3.    What is meant by core logging? Typically what parameters would typically be recorded when undertaking core logging? 

4.    What is meant by the popularly-used word transparency?

5.    Describe in detail an electrical exploration technique.

6.    What is reverse cycle drilling? How does it differ from normal drilling?

7.    What is meant by the following terms:

• Range
• Variance
• Standard deviation
• Kurtosis
• Skewness

8.    Illustrate and discuss the effect of support on grade-tonnage relationships used to assess selective mining units.

9.    What are the rules regarding the reporting of exploration results?

10. Give three likely examples of support that might be used in a mining estimation, and explain how you would change from one to another.

11. Describe a polygonal estimation technique.

12. Give an explanation of why kriging techniques are preferable to other estimation methods.

13. Explain what a "competent" person means in the JORC. What qualifications do competent persons require?

 

14. Determine the variance for the grade data set in the following table

Sample Number	Grade Au g/tonne
1	4.6
2	7
3	2
4	1
5	5.3
6	6.5
7	8
8	21
9	0.2
10	3

 

15. What is meant by:

• 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 0.9 tonne/m³. Note surface is flat and top of coal seam for all boreholes is intersected at the same depth.

Property Coordinates

East	North
1000	1000
7000	1000
1000	7000
7000	7000

 

Drill hole data

Drill hole	Seam thickness (m)	East Coordinate	North Coordinate
1	5	2000	1000
2	4.5	4000	1000
3	3.5	6000	1000
4	4	1000	3000
5	5	3000	3000
6	3.9	5000	3000
7	3.7	7000	3000
8	4.5	2000	5000
9	4.6	4000	5000
10	4.8	6000	5000
11	3.9	1000	7000
12	5.6	3000	7000
13	2.9	5000	7000
14	2.8	7000	7000

 

17.    What characteristics of an ore body, besides grade, could or should be treated using geostatistical methods?

18.    Give definitions for the following:

- Break-even cut-off grade 

-Geological cut-off grade 

- Incremental cut-off grade 

- Marginal cut-off grade 

- Optimal cut-off grade 

- Resource/reserve cut-off grade 

- Run of mine cut-off grade 

19.    Define the various categories of reserves and resources that can be employed under JORC.

20.    Detail any special requirements for reporting nuggetty gold deposits within the JORC Code?

21.    How does the JORC code deal with stockpiles, low grade mineralisation and tailings?

22.    Why do you need a mathematical expression to represent the experimental variogram?

23.    What is meant by covariance?

24.    What type of information concerning the deposit is provided by a variogram?

25.    Use the method of polygons to determine the average ore grade and tonnage represented by the information on the next page if the cut-off grade is 2.5% and the ore has a density of 2.5 tonnes/m³.

26.    What would be the impact on the answer to question 25 if the cut=off grade is increased to 3%?

 

Drill hole id number	Collar elevation (m)	Easting coordinate (m)	Northing coordinate (m)	Depth to mineralised zone (m)
1	1000	1000	1000	100
2	1050	1500	1000	150
3	1060	2000	1000	160
4	1010	2500	1000	110
5	1020	1000	1500	120
6	1070	1500	1500	170
7	1050	2000	1500	150
8	1000	2500	1500	100
9	1040	1000	2000	140
10	1020	1500	2000	120
11	1000	2000	2000	100
12	1070	2500	2000	170
13	1040	1000	2500	140
14	1010	1500	2500	110
15	1020	2000	2500	120
16	1000	2500	2500	100

 

		Incremental sequence of samples taken from the mineralised zone
	Hole id #	10m	15m	20m	10m	5m	10m	5m	20m
Sample Grades In %	1	3	2	2.5	3.5	3.8	3	1.7	1.6
	2	3.5	3	2.5	2	2.5	3	2	1.5
	3	4	4.2	4.4	4.5	4	3.5	2	1.6
	4	3.2	2.7	2.5	3.2	3	2.5	1.5	1.4
	5	4	3.5	2	2.2	2	1.7	1.6	1.5
	6	3.2	2.8	3	3	2.5	2	2.2	1.4
	7	4	3.5	2.2	2	2	1.6	1.5	1.2
	8	3.5	3	2.5	2	2.5	3	2	1.5
	9	4	3.6	3.2	3.4	3.1	2.6	1.6	1.2
	10	3.7	3.8	3.5	3.4	2.7	2.3	1.7	1.4
	11	3.2	3	2.8	2.6	2.4	2	1.9	1.5
	12	3.8	3.9	4.2	4.1	3.4	2.7	1.5	1.2
	13	3.8	3.2	3	3.4	2.4	1.7	1.5	1.5
	14	4.3	4	4.1	3.4	2.7	2.4	2	1.2
	15	4	3.8	2.7	3.2	2.6	1.6	1.4	1.1
	16	3.6	3	3.1	3.1	2.2	2	1.7	1.4

 

North Boundary of the property 2500mN

South Bindery of the property 1000mN

East Boundary of the property 2500mE

West Boundary of the property1000mE School of Engineering and Information Technology

27.

1.               The table below shows the Copper ore grade results from a core drilling program undertaken on a regular 100m x 100m grid.

			Copper ore % Cu at coordinate values
			Easting Coordinate (m)
		0	100	200	300	400	500	600	700	800	900
	0	0.50	0.55	0.60	0.70	0.73	0.83	0.74	0.52	0.5	0.5
	100	0.72	0.74	0.75	0.73	0.72	0.83	0.79	0.72	0.70	0.70
	200	0.72	0.82	0.83	0.82	0.81	0.83	0.75	0.71	0.71	0
	300	0.71	0.71	0.69	0.90	0.91	0.81	0.82	0.83	0.81	0.71
	400	0.82	0.84	0.81	0.83	0.83	0.82	0.82	0.81	0.81	0.71
	500	0.82	0.91	0.82	0.83	0.82	0.82	0.81	0.81	0.71	0.71
	600	0.54	0.64	0.65	0.72	0.69	0.63	0.71	0.72	0.75	0.80
	700	0.70	0.71	0.78	0.79	0.65	0.66	0.67	0.65	0.71	0.71
	800	0.71	0.72	0.68	0.85	0.84	0.80	0.81	0.80	0.81	0.80
	900	0.70	0.81	0.84	0.78	0.80	0.81	0.81	0.81	0.70	0.70

 

Undertake classical statistics on this data set, calculating the mean, variance and standard deviation.

2.               Using the data from question 21, determine experimental variograms in the west to east and north to south directions.

3.               Use ordinary kriging to estimate the grade at the location 475m East, 350m North.