mineral resources Flashcards
in what 3 ways does the lithosphere provide resources and services
physical resource (mined metals ores, non-metal minerals and fossil fuels) biogeochemical cycles (recycle essential biological elements eg carbon nitrogen and phosphorus) soil (growth medium for plants, habitat for many organisms, location for part of all biogeochemical cycles)
why are mineral resources extracted from the lithosphere non-renewable
they reform too slowly to be replaced within timescales of human use
how can you extend the use of non-renewable resources
understanding of scientific methods to increase supply, extend use and find alternatives
name a fossil fuel and its important uses and properties
coal - fuel, especially for electricity generation - high energy content / crude oil - fuels, especially liquid fuels for vehicles - high energy content / natural gas - fuel, especially heating and electrical generation - high energy content
name a metal and it’s important uses and properties
iron - construction - malleable, strong but high density, rusts, forms alloys eg stainless steel / aluminium - packaging, vehicles, construction - malleable, strong but low density, good heat and electricity conductor, corrosion resistant / copper - electric cables, water pipes - malleable, good electrical conductor, corrosion resistant
name a non metal mineral and it’s important uses and properties
sand - builders mortar, glass - fine-grained inert filler, transparent in thin sheets / gravel - concrete - coarse-grained filler / limestone - building blocks, cement, crushed for road surface chippings - hard, easily cut and crushed, quite resistant to wear, baked lime
how is basalt formed
by lava that cools quite quickly
what forms slower, magma or lava and why
magma since it’s insulated underground
why is basalt black and granite multicoloured with crystals
basalt rock was formed by lava cooling quickly so it’s black whereas granite cooled slower
where does earth’s internal heat come from
decay of radioactive materials in the mantle and crust / heat left over from the collisions of millions of rocks that formed earth billions of years ago
why are fissures in batholiths important
they allow the formation of economically-important mineral deposits through a process called hydrothermal deposition
how are individual mineral deposits from batholiths formed
the heat surrounding the groundwater from the batholith creates hot mineral solutions that flow away from the batholith along fissures / they cool as they move away from the batholith and fractional distillation occurs, so different minerals precipitate out of the solution
where do sedimentary processes occur
at the surface of the lithosphere
name a simple type of sedimentary process
when a rock that already exists is broken down by weathering into rock particles and dissolved minerals in a solution, which are carried away and redeposited elsewhere as rocks with different compositions and properties
what are the four main types of physical sediments
alluvial deposits / evaporite deposits / secondary enrichment / chemical precipitation of poly metallic nodules
how are alluvial deposits formed
when minerals are weathered and eroded from surrounding rock, transported by flowing water and deposited when the water slows down
what effect do alluvial deposits have on rivers
rivers widen and flow less steeply as they get to the sea, reducing velocity of over flow and waters kinetic energy
how are evaporite deposits formed
when water evaporates from mineral rich solutions
what is secondary enrichment
when minerals are carried down into the ground and end up redeposited when oxygen levels drop (due to minerals being insoluble when oxygen is removed)
why is the concentration of metal much higher in secondary enrichment
because the redeposition occurs quite suddenly
what is chemical precipitation of polymetallic nodules
metal rich nodules found on the seabed, may have been formed by chemical precipitation of metals around a small solid object
how are biological sediments produced
from dead animals and plants being subjected to intense heat and pressure having been buried deep beneath the earth’s surface
what was the original material of limestone and chalk
shells of marine organisms
what was the original material of coal
terrestrial vegetation
what was the original material of crude oil and natural gas
marine organisms
give 3 examples of metamorphic changes
limestone -> marble / mudstone -> slate / granite -> gneiss
name the two types of exploratory techniques for discovering deposits
remote sensing and survey techniques
what is remote sensing
involves technique that gives information about the lithosphere without taking direct samples. can collect data on a range of scales: satellite surveys, aircraft surveys and ground based surveys
what is the disadvantage but advantage to larger scale surveys compared to remote sensing
they’re more expensive but they’re more cost effective, provide a lot of information at a relatively low cost per unit area surveyed
name 6 survey techniques
infrared spectroscopy / gravimetry / magnetometry / seismic surveys / resistivity / trial drilling and chemical analysis
what is infrared spectroscopy
identifies different wavelengths of IR emitted by differentiations minerals
what is gravimetry
detect variations in gravity caused by variations in density and total mass below the instrument. more dense = higher mass = stronger gravitational pull
what is magnetometry
detects more magnetic rocks underground
what are seismic surveys
involve sound waves produced by controlled explosions or a seismic vibrator on the surface. echos give information about depth, density and shape of rock strata
what is resistivity
the measurement of difficulty with which electricity passes through a material to read resistivity and work out the rock type (low water content = high resistivity as electricity can’t pass through the rock)
what is trill drilling and chemical analysis
produces samples of the rocks underground, lab test confirm chemical composition and purity of the minerals in the rock samples (most expensive)
what are the 8 factors that must be assessed before you set out mining
ore purity / chemical form / overburden and hydrology / depth / economic viability / transport costs / market economics: supply and demand / environmental concerns
what happens if the ore grade is low
more rock will have to be mined to obtain a given amount of desired metal / more waste material will be produced / more energy will be needed for mining and processes / more pollution will be generated
why is chemical form a factor to be assessed when mining
because it affects the ease of chemical extraction
why is overburden and hydrology a factor to be assessed when mining
hard overburden may need to be blasted which increases cost / loose overburden could increase the risk of landslides, sides may have to be at more of a gradient -> increases overall area of the mine -> higher precipitation = higher drainage cost
why is depth a factor to assess in mining
depth increases = cost increases / as depth increases, amount of rock to be removed to reach the mineral rises rapidly / depth increases, more water flows into the mine from surface run off = pumping cost increases
why is economic viability a factor to assess in mining
mining must be economically profitable, balance between production cost and income / affected by market demand and sale
what changes the Cut off ore grade (COOG)
as technology improves / as market prices fluctuate
why are transport costs a factor to assess in mining
affected by distance to market, ease of bulk transport, presence of suitable existing transport and wether the bulk of material has been reduced by processing / lots of factors that can dramatically reduce or increase the cost
why are market economics a factor to assess in mining
supply and demand / market price is controlled by demand of the mineral. amount supplied changes relatively slowly but demand can change rapidly
why are environmental concerns a factor to assess in mining
mining may be banned to protect key wildlife species (eg Antartica treaty)
what is a resource
a theoretical maximum of what is available to be exploited
what is the reserve
what can actually be exploited under current conditions
why do we use a logarithmic scale in lasky’s principle graphs
it is easier to plot due to rapid increase in quantity of mineral
what is lasky’s principle
minerals are mostly found in low-purity ores, which presents a greater challenge for metal production. The ability to exploit low-grade deposits therefore results in a large increase in the reserves
what is the impact on the COOG if the market value increases
COOG decreases
what is the impact on the COOG if the market value decreases
COOG increases
what happens to the COOG with improved extraction technology
COOG decreases
what happens to the COOG with higher energy costs
COOG increases
what happens to the reserve as the COOG goes down
the reserve increases
in mining how does exploration have an environmental impact and how is it controlled
marine seismic surveys interfere with whale communications, could cause hearing loss in marine mammals, exploration on land could cause vegetation loss / ban seismic surveys if whale spotted, replant vegetation
in mining how does land take have an environmental impact and how is it controlled
extraction can cause conflict with existing land uses, minerals can only be exploited where they’re found, increases land use conflicts ass limited choice of location / deep-shaft mining because it has less impact over open-cast
in mining how are habitats affected and how is it controlled
habitat loss, loss of species, dredging sand from seabeds can disrupt aquatic habitats / capture and transplant animals to an unthreatened habitat, habitat restoration
what impact does mining have on the amenity of the land and how could it be controlled
loss of amenity, causes aesthetic problems / can be reduced by landscaping and tree planting
mining creates dust, how can this be controlled
water sprays - make dust particles heavier so they settle out
mining creates noise pollution, how can this be controlled
baffle mounds or fencing to absorb or reflect the sound / restricted times for blasting eg no blasting at night
what environmental impact does mining have on overburden rock
creates spoil = spoil heaps, spoil instability can cause landslides or erosion / landslides can reduce drainage, compaction and landscaping
what is the environmental impact causes from transport and how can we control it
produces noise, fumes, dust and causes traffic accidents / reduced by water sprays to suppress dust, careful route choices away from residential areas
what is the environmental impact that could come from mine shafts and tunnels and how can we control it
subsidence / leave support pillars in place underground
what is the environmental impact from drainage water from mining and how can we control it
drainage water becomes turbid and smothers aquatic plants and silt up rivers / turbidity can be reduced by sedimentation lagoons where water stands still enough for sedimentation to sink, so outflow has a low turbidity
how does mining cause toxic leachates and how is this controlled
rainwater percolates through spoil dissolving sulphates that produce acidic leachate solutions, toxic metals may have dissolved and become mobile / toxic metals are more soluble under acidic conditions, filter mine drainage water through a filter of limestone to precipitate out the metal and prevent it being carried into rivers
new technology needs to be developed to find and extract new deposits, what should the newly manufactured products be designed to do better
minimise the amount of material needed and extend the lifetime of material use
name the 2 types of exploitation of low grad ores
bioleaching and phytomining
what are the advantages of recycling in mining
conservation of mineral resources / reduced energy use / reduced mineral extraction / reduced waste disposal impacts
what are the difficulties with recycling schemes in mining
identification of materials / operation of mixed materials / reduction in quantity / increased transport costs / collection difficulties / lack of consumer cooperation
