Mineral resources Flashcards
Define mineral
- a solid, naturally occurring inorganic substance with a definite chemical structure
Define resource
- a source of supply or support
What is a sedimentary rock
- a rock that has formed through the deposition and solidification of sediment, limestone and chalk
What is a metamorphic rock
- started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary or earlier metamorphic form
What is an igneous rock
- types of rocks that are formed when molten rock cools to a solid state
Proterozoic marine
- iron ions were present in oceans in solution
- iron ions react with O2 to form iron oxides
- iron oxides form deposits on ocean floors
Describe how alluvial deposits can separate and concentrate valuable metals and minerals
- rivers with high energy and velocity carry lots of sediment
- as energy and velocity decrease, sediments drop out of suspension and are deposited
Explain the process of secondary enrichment
- metal ores are exposed at the surface
- exposed to oxygen and water
- metal oxidises and goes into solution
- water perculates downwards until it reaches the water table
- metal reduces
- metal precipitates
- copper is concentrated just below the water table
Explain how evaporites form
- sea levels decrease
- temporary lakes may also form
- water contains salts
- water evaporates
- salt precipitates and deposits on land
Explain how biological deposits can form sedimentary rocks
- they are remains of living organisms
- over time, remains lithify
- e.g coal - formed from terrestrial vegetation
Explain how granite batholiths are formed
- large volume of magma that moves up through the earth’s crust, but doesn’t reach the surface
- cools and solidifies in the crust to form granite
- associated with tectonic plate movement
Explain how hydrothermal metal ores are deposited
- via hydrothermal deposition
- hot magma rises through lithosphere
- water in surrounding rocks become superheated
- metals and minerals go into solution
- how water moves away from magma along fractures
- water cools
- metals and minerals precipitate out of solution at different temperatures
Explain how slate is formed
- formed from shale
- undergoes heat and pressure
- becomes slate by changing
Explain how marble is formed
- formed from limestone
- undergoes heat and pressure
- becomes marble by changing
Define reserve
- the amount of the resource that is economically viable and can be exploited with today’s existing technology and prices
Define stock
- all of the material on the lithosphere that exists
How might a reserve increase
- develop new technology
- increase value
- cost of labour decrease
How might reserves decrease
- problems with equipment supple
- increase labour, equipment and energy cost
- decrease value
What is lasky’s principle
- as purity of a mineral decreases the amount of the mineral increases exponentially
Define cut off ore grade
- the grade of material that has been set by a mining company as the minimum grade that can be extracted to make a profit
Why might the cut off ore grade change over time or from place to place
- deeper deposits - harder to extract
- decrease value - increase cut off grade
- increase value - decrease cut off ore grade
Why do we need to survey before extraction of materials begins
- to see what is there and how much is present
What is IR spectroscopy
- measures what materials emits what amounts of IR and at what wavelengths
What is gravimetry
- measures of gravity
- high gravitational pull, then it’s very dense below the surface
What is magnetometry
- uses magnets to deflect rocks that may be magnetic
- positive magnetic reading = cobalt, nickel and iron
What are seismic surveys
- produce artificial seismic waves by having a loud noise at the surface
- 5W are reflected back to the surface
- used to locate depth of the deposit
What is resistivity
- two probes are put in the ground
- electric current is passed through
- low resistivity = high conductivity
What is trial drilling
- physically collect a sample of rock
- most expensive
What is chemical analysis
- send sample to a lab
- confirms presence or absence of valuable material
- determines purity
How does location in relation to existing infrastructure affect the viability or extraction of minerals
- if there are no roads, water supply etc = extra costs
- some existing buildings may need to be moved
How does location in the ground (depth) affect the viability or extraction of minerals
- higher up = easier to mime
- the deeper the material = the more costly the operation
How does purity affect the viability or extraction of minerals
- lasky’s principle - higher the purity the more viable the mining operation will be
- lower purity = higher quantity
How does the hydrology affect the viability or extraction of minerals
- if there’s a large aquifer underground, they will either go around it or stop mining
- they’ll have to pump water out which is costly
How does chemical form affect the viability or extraction of minerals
- valuable metals can form in different ores
How does the availability of technology affect the viability or extraction of minerals
- increase availability = easier but more expensive
- lower availability = harder and expensive
How does economic viability affect viability and extraction of minerals
- after considering all factors, they establish a cut-off ore grade
How does transport costs affect viability or extraction of minerals
- increase transport costs = lower mine viability
- e.g insurance, fuel, vehicles etc
How does market economics affect viability or extraction of minerals
- unstable value = lower mine viability
- stable value = high mine viability
What are some environmental impacts of mineral exploitation
- habitat loss
- air pollution
- noise pollution
- increased turbidity
- flooding
- subsidence
How can we extend the time period that existing reserves can be exploited
- place restrictions on the amount of material we extract
- improve technology
- recycle existing materials
2 examples of improved exploratory techniques
- improved remote sensing e.g satellites
- portable field equipment
What is bioleaching and what are some benefits
- extracting metals from a low-grade ore with the help of microorganisms
- bacteria is mixed with metal ore and carries out a chemical reaction
- doesn’t require drilling
What is phytomining and what are some benefits
- mining metal using plants, extracting them from low-grade ores in the soil
- plants concentrate metal in their tissues
- doesn’t require drilling
What is iron displacement and what are some benefits
- introduce a more reactive metal so it displaces the oxidised metal
What is leachate collection and what are some benefits
- liquid that is contaminated with something
- rainwater can perculate through the soil heaps and produces a leachate that has valuable metals in it
What is polymer adsorption and what are some benefits
- long strands of plastic (negative charge)
- uranium has a positive charge
- sticks onto polymer strands
- adsorb very dilute metals from seawater
What is a deep sea polymetallic nodule
- rich in metal
- it concentrates on the sea floor formed of concentric layers of iron and manganese hydroxide
How do polymetallic nodules form
- hydrogenous process in which concretions are formed by the slow precipitation of the metallic components from seawater
How can we extract polymetallic nodules
- a vacuum to systematically dredge large swaths of the sea floor
- any unwanted material that reaches the surface vessels is put back into the ocean
What are some environmental impacts of deep sea mining
- increase turbidity
- destruction of habitats
- disrupt aquatic life
What are the advantages of recycling
- protects ecosystems and wildlife
- saves energy
- creates jobs
- improve education
- reduces noise and air pollution
What are the disadvantages of recycling
- expensive
- can lead to pollution
- can still release CO2
- it can smell
What is meant by the cradle to cradle design and how does this benefit both the environment and industry
- all materials should be in a continuous cycle of use
- design and makes parts that are easy to identify and deconstruct
- very little waste material
