Using Resources Flashcards
(20 cards)
What is considered in LCAs
Extraction and processing of raw materials
Manufacturing/packaging
Use over its lifetime
Disposal
Transportation
How does iron rust
It reacts with oxygen+water
How does copper corrode
It reacts with oxygen
What are sacrificial metals
Cover materials that will corrode before the important metal underneath
What is covering another metal in zinc called
Galvanising
Bronze
Copper + tin
Brass
Copper + zinc
Why are alloys stronger
Different sized atoms disrupt the lattice, so layers cannot slide over each other as easily.
When is aluminium used in alloys
When a low density is needed
Soda-lime glass
Made heating sand, sodium carbonate and limestone
Borosilicate glass
Sand + boron trioxide
Pottery
Heating shaped clay in a furnace
Composites
Combination of two materials (not two metals though), usually resulting in strong and light materials (eg carbon fibre)
Matrix vs reinforcement
Matrix- binds the reinforcement together
Reinforcement- makes up the bulk of the composite
How to change the density of your poly ethene
Change the conditions when produced (LDPE uses higher temperatures, HDPE lower)
Thermosoftening vs thermosetting
Thermosoftening melt when heated, whereas thermosetting do not, due to the crosslinks between the polymers, which have strong covalent bonds and are therefore difficult to break
Haber process how to get reactants
Nitrogen- air
Hydrogen- electrolysis of water
Conditions for haber process
450 degrees at >200 atm
Higher pressure favours forward
Higher temperature increases rate but also favours reverse (so 450 is a compromise here)
What are NPK fertilisers made from
Nitrogen, phosphorus and potassium salts
How to obtain the compounds for NPK fertilisers
Nitrogen- air
Potassium- from chloride and sulphate obtained by mining
Phosphorus- phosphate rock is mined and treated with an acid
