mineral exploitation

Question 1

define Lasky’s principle

Answer 1

as the purity of a mineral decreases the amount of that mineral present increases exponentially

Question 2

outline Lasky’s principle

Answer 2

the idea that the major problem with mineral deposits is not the quantity that exists but the need to develop methods to exploit low grade deposits economically

Question 3

what is the difference between a reserve, resource and stock

Answer 3

1) defined as the amount of resource that can be exploited now with the existing economy and technology
2) the amount of mineral which can be exploited now and theoretically in the future depending on advancements in tech and economy
3) all the material which exists in the lithosphere now- including what we can exploit now, in the future and what we can never exploit

Question 4

list the different survey techniques for mineral exploration

Answer 4

1) IR spectroscopy
2) gravimetry
3) magnetometry
4) seismic surveys
5) resistivity
6) trial drilling

Question 5

outline IR spectroscopy and gravimetry

Answer 5

1) different minerals emit IR at different wavelengths and these can be used to identify them
2) gravimeters detect variations in gravity caused by variations in density and mass

Question 6

outline magnetometry and seismic surveys

Answer 6

1) manometers detect rocks that are more magnetic such as iron ore.
2) involve sound waves produced by controlled explosions or seismic vibrators on the surface- echoes give info about depth, density and shape of rock

Question 7

outline resistivity and trial drilling

Answer 7

1) the measurement of the ease electricity passes through a material to identify the type of deposit
2) drilling to produce samples of rock which can then be chemically analysed to conform chemical composition and purity of minerals

Question 8

list factors which affect mining viability

Answer 8

1) ore purity
2) chemical form
3) overburden
4) depth
5) cut off ore grade
6) transport cost
7) market demand

Question 9

outline how ore purity effects viability of mining

Answer 9

• how pure it is affects financial costs
• if it is low grade then more rock will need to be mined
• more waste material produced
• more energy needed for mining
• more pollution generated

Question 10

outline how chemical form influences viability

Answer 10

refers to the ease of chemical extraction of the metal

Question 11

outline how overburden effects viability

Answer 11

the rock which lies above a mineral deposit

• hard overburden may require energy intensive procedures to remove it
• loose overburden may increase risks of land slide
• some of the materials that make up overburden may be able to be sold to make profit

Question 12

outline how depth affects mining viability

Answer 12

• as depth increases so does cost of extraction
• the sides of the mine cant be vertical in case of collapse therefore more rock must be removed to reach deposits
• as depth increases the amount of water that flows into the mine from surface run off also rises increasing pumping cost

Question 13

what is the cut off ore grade and how does it affect viability

Answer 13

1) the lowest purity ore which can be mined economically using existing tech
2) the cut off ore grade increases or decreases depending on existing tech and economics

Question 14

how does market demand affect viability

Answer 14

• if demand is high the more can be mined and the lower purity can be economically mined
• if demand is low it is not viable to mine lower purity ores