topic 10 continued Flashcards
why is extracting metals bad
as it uses a lot of energy
-produces large amounts of toxic waste
how is metal extracted
- the ore has to be dug out of the mine and transported for processing
- the metal has to be extracted from the ore and this can produce large amounts of toxic waste
how are plastic bags produced
using chemicals from crude oil
how are paper bags made
from wood from trees
why is crude oil bad
- it is non-renewable
- extracting crude oil can be harmful to habitats eg. if there is an oil leak
why are felling trees bad
as it is extremely destructive to habitats such as forests
what process do crude oil and wood need to go through
they need to be chemically processed
why is chemical processing bad
- requires a lot of energy
- releases waste products
what does making paper require
large amounts of water
how are paper bags bad- they require …
they require lots of energy to be transported as they are heavier
what is the disadvantage of plastic
it is non-biodegradable - it is not broken down by microorganisms so this creates lots of litter
how are most metals found
in the earth’s crust already reacted with other elements
give an example of a popular metal
copper
what does a metal ore contain
enough metal to make it economical to extract the metal
what is the problem with copper ores
they are running out
as copper ores are starting to run out what are we going to have to do next
extract copper from low-grade ores
what do low-grade ores contain
a very small amount of copper
what is the drawback from extracting copper from low-grade ores
it is very hard to extract the copper economically from the ores`
what is phytomining- (plants)
plants are grown on land containing the metal compound that we want
what do phytomining plants do (2)
- absorb the metal compound and they concentrate it in their tissue
- the plants are then harvested and burned
what does the ash (burned and harvested phytomined plants) contain
a high concentration of the metal compound
what does bioleaching use
bacteria
what happens in bioleaching
bacteria are mixed with low-grade ore
what does the bacteria do in bioleaching
the bacteria carry out chemical reactions and they produce a solution called a leachate
what does the leachate contain
a metal compound that we need
what do phytominign and bioleaching both allow us to do
economically extract metals from low-grade ores
how do we recycle metals
by melting them and then recasting them into different products
what is the problem of recycling metals
different metals need to be separated before recycling- this depends on the properties of the final product
what can some scrap steel be added to
iron from a blast furnace- this reduces the amount of iron we need to extract from the iron ore
how can glass bottles help sustainability `
by reducing the amount of energy needed to make new glass products, and also the amount of waste created when used glass is thrown away`
by what 2 ways is glass separated by
colour and chemical decomposition
what has been developed to reduce the amount of energy required for industrial processes
catalysts
what is the problem with life cycle assessments (2)
- they can be bias
- doesn’t fully show the effects of the products
