Lithosphere Flashcards
What are mineral deposits
Reas of high concentration that are exploitable
Industrial uses of minerals (aluminium and titanium)
planes
Geological processes (igneous)
- Hydrothermal deposition
- igneous intrusion (superheated water dissolving rock minerals)
- fractional crystallisation further from the batholith (different melting points of minerals)
Geological processes (metamorphic)
- tectonic movement altering existing igneous rock (high temp and pressure)
- limestone becomes marble
- mudstone becomes slate
Geological processes (sedimentary)
intervals settle and build up in deposited layers (concentrated lines of mineral):
- Proterozoic marine sediments
- evaporates
- Alluvial deposits
- Secondary enrichment
- biological sediments
What happens when land (overburden and ores) are removed from the ground
- lack of surface compaction
- soil instability (erosion)
- subsidence
What are protozoic marine sediments
haemite and magnite from dissolved iron compounds oxidising insoluble iron deposits
What are evapourates
Ancient sea bays evaporate leaving crystallised sodium chloride (salts)
What are Alluvial deposits
Matter carried by water e.g. gold, diamonds, sand and clay (dependant on water velocity and density of the minerals)
What is secondary enrichment
Metals becoming soluble if they are oxidised (otherwise they remain insoluble) this usually happens in water where oxygen is present
What are biological sediments
Living organisms being deposited to form sedimentary rock
- shells form limestone
- vegetation forms coal
- marine organisms form rude oil and natural gas
What is the lasky principle
As the purity of a mineral decreases the amount of internal present increases exponentialy
What is the resource
the amount of mineral present that could be mined (the tech is available) but is currently not economically viable due to ring to low grade or the tech not being efficient enough
What is the reserve
The amount of the mineral that can be mined and is economically viable with the current techand grade
What is the COOG
The cut off ore grade (minimum percentage of the mineral present in rock to be economically viable to mine)
Why are more lower grade ores being explited
Economic viability:
- the demand is growing
- the tech is advancing and becoming more efficient
What happens to reserves as tech advances
They increases
What happens when the COOG dereases
Lower grade ores become economically viable
What is stock
The total quantity of the mineral on earth that is currently not all accessible due to tech not being advanced enough (also not economically viable)
Types of reserves
- inferred
- probable
- proven
What are inferred reserves
The prediction of a mineral deposit based on geological structures, not about the size or economic viability
What are probable reserves
Knowledge about the deposit and the amount of mineral present there with an estimate of grade, further exploration is justified
What is a proven reserve
Explorations with trial drills that accurately prove the quantity and grade of the mineral, ready to mine
What are the factors of exploitation viablity
- quality/ advancement of technology needed
- financial cost
- environmental impacts
Explorative surveys methods (for mining)
- IR spectometry
- gravimetry
- magnetometry
- seismic surveys
- resistivity
- trial drilling
- chemical analysis
What is IR spectometry
Minerals emitting IR at afferent wavelengths (used to identify the type of mineral)
What is magnetometry
Ores and magnites are more magnetic than normal rock (used to detect location and grade)
What are seismic surveys
Sound waves from small l explosions echo Ito the ground that then is returned (into about the density and shape of the rock strata)
What is resistivity
measuring how difficultly electricity passes through the material (sedimentary are less resistive than igneous as thehave higher water contents)
What is trial drilling
(the most expensive method) produces samples of the rock from underground to be analysed for quality and quantity
What is chemical analysis
Lab tests that confirm the chemical composition and purity of the minerals in the rock samples from trial drilling
What s gravimetry
Variation in gravitational pull up to the density and mass of minerals (igneous is more dense than sedimentary)
Environmental impacts of mining
- land use conflicts
- habitat loss
- eye sores to the landscape (loss of amnety)
- dust air (can be reduced with water sprays that sinks them)
- noise pollution
- water turbidity
- solid (waste rock) spoil disposal issues
Exploritary techniques
- remote sensing (image resolution)
- deep mining is safe (roof supports)
- open cast is cheaper (tech advances)
Low grade mineral extraction techniques
- bioleeching
- phytomining
- iron displacement
- leachate collection
- polymer adsorption
What is bioleeching
Bacteria extracts copper, zinc, lead and gold in low grade through producing oxides and acid that dissolves the metals
What is phytomining
Plants absorb metal ions from the ground and concentrate them in their leaves (burnt to have the high concentration)
What is iron displacement
Iron is ore reactive tha copper which displaces copper ions from a solution (turning he copper into a solid that can be colected)
What is leachate collection
Percolating rain water dissolves soluble metal ions, absorbs them into a higher concentration so it can be extracted through electrolysis
What is polymer adsorption
Metal ions dissolved in sea water adsorbs on the surface of polymers that can be collected. (Polymers can be synthetic or natural eg lignin or shrimp shells)
What resource can be exploited that was previously inaccessible
Pollymetalic nodules (5 to 10 cm diameter 4,000 to 5,000 letters below the sea) 30% manganese and other minorities eg iron, copper, nickel or titanium
Recycling minerals issues
- transport osts
- labour costs
- separation time
- identification time
- energy costs
- public cooperation
- waste losses
What is the cradle to cradle design
Designing products so that the materials can be reused till the end of their useful lives (easy separation of opponents and identification of materials) for a circular economy
