Chem (Extraction of metals) Flashcards
Adavntages of using scrap metal as opposed to metal extraction?
- lower energy costs
- Doen’t use up valuable ores
- Recyled metal-still retain properties indefinitely
- waste going to landfill is reduced- less damage to environment
- carbon emission reduced/pollution
Advantages of using metal extraction instead of reduction by carbon monoxide?
Blast Furnace-high enrgy costs
Aqeuous solution- lower temperature
Blast Furnace- emissions of C02/air and water pollution
Metal extraction using aqueous soltion use..?
low-grade ores
Extraction of aluminium- main ore is..?
high % of ..?
bauxite
Al203
Why is olten cryloite added in with the Al203 during electrolysis?
because it reduces the melting point from 2000 degrees to 900 degrees
easier to melt
reduces energy costs
What is reduced in extraction of aluminium?
Al3+ + 3e- > Al
What is oxidisied in the extraction of aluminium?
202- > 02 + 4e-
oxygen is always oxidised
What are high enrgy costs due to and ho doy uo reduce them?
Electricity process
Red Mud Waste>landfills
Extraction of Titanium- main ore
Ti02
Why can’t you displace it with carbon? and what do you do with it instead?
because it priduces a useless brittle metal, TiC
heat it with chlorine gas, Cl2 to make TiCl4
What do you react titanium chloride with to make the titanium metal?
TiCl4 + 2Mg > Ti + MgCl
TiCl4 + 2Na > Ti + NaCl
Why do yuo use an inert atmosphere of argon gas for ttinaium extraction?
So the metals don’t react with 02 in the air
Why is titianum production expensive?
Kroll process is expensive to operate
Cl2 is expensive to produce
Ti is more expensive to produce than stainloess steel
Old processes of extracting cooper means.?@
S02 emissions- acid rain
Sulfuric acid can eb manufatured by :
S02 + H20 > H2S03
H2S03 + 1/2 02 > H2S04 (suluric Vl acid-common one)
