Metallurgy Flashcards
Abundance of Al
8.3% and third most in overall and 1st in metals
Ruby composition
Al2O3 with Cr as impurity
Sapphires composition
Al2O3 with Co has impurity
2nd most abundant metal
Iron
Al ore
Bauxite
Kaolinite
Fe ore
Haematite
Magnetite
Siderite
Iron pyrite
Cu ore
Copper pyrites
Malachite
Cuprite
Copper glance
Zn ore
Zinc blende or sphalerite
Calamine
Zincite
Undesirable material
Gangue
Benefaction
Concentration
Difference in specific gravity
Hydraulic washing
Sulphide ores
Froth floatation method
Collectors
Pine oil, fatty acid, xanthates
Enhances wetting of the minerals
Stabilizers
Cresols, aniline
Stabilizes the froth
Mineral gets wetted by and gangue by
Oils and water
Two sulphide ores can be separated by
Adding depressants like NaCN in case of ZnS and PbS
ZnS doesn’t come to the froth but PbS does
Bauxite impurities
SiO2 and iron oxides and titanium oxide
Leaching if aluminum
Addition of con NaOH at 473 to 523 k at 35-36 bar called digestion
Sodium aluminate is neutralized by adding
CO2
Addition hydrated Al2O3 to the solution
Seeding for precipitation
Leaching
Al, Ag and Au
Au and ag is leached with
Dilute NaCN and KCN
Calcination
Vaccum for carbonates and hydrides
Roasting
In the presence of air and for sulphide ores
Sulphide ores of cu are heated in
Reverberatory furnace
FeO + SiO2
FeSi03 ( slag)
Extraction of iron from its ore
What is mixed with the ore
Limestone and coke
Extraction of iron from its ore
Which provides the necessary heat for the reaction
Burning coke
Extraction of iron from its ore
At 500 to 800 K what conversions occur
Fe2O3 to Fe3O4
Fe3O4 to Fe and CO2
Fe2O3 to FeO and co2
All reactions in the presence of CO
Limestone decomposes to CaO and reacts with?
Silicon impurities to from slag CaSiO3 (900-1500K)
Above what temp is the reaction spontaneous
1073K
4% C contains iron
Pig iron
Cast iron
3% C
Wrought iron or cast iron
Prepared form cast iron in reverberatory furnace having haematite lining
Cu from cuprous oxide extraction
Cu2S +3O2 - Cu2O
Cu2O + C - cu + co
FeO + SiO2 - Fesio3
Cu2S + Cu2O - Cu + So 2 ( cu obtained is called blister copper due to release of so2
Copper matte
Cu2S and FeS
Zinc from zinc oxide
Zinc oxide with coke to give zinc and co
Rapid chilling
Hall Herodotus process
Al oxide is mixed with Na3 AlF6 or CaF2
Which lowers the melting point of the mixture
Carbon carbide and graphite abide
Cu from low grade ores
By hydro metallurgy
Leached using acid or bacteria
In gold and silver leaching with cn what is used as reducing agent
Zinc
Distillation
Low boiling metals
Zinc me mercury
Liquation
Low melting
Tin
Electrolytic refining
Impure metal as anode and pure metal as cathode
Copper - electrolyte is cuso4
zinc
Zone refining
High purity - gallium, germanium, silicon, boron,indium
Vapor phase refining
Monds recess
Van arkel method
Volatile metal
Easily decomposable
Nickel
Zirconium and titanium
Chromatographic method
Paper chromatography and column chromatography
Column is used for minute particles and not very different chemical properties
Bronze composition is
Copper and tin
Brass composition
Copper and zinc
Coinage alloys
Copper and nickel
German silver
Cu - 25-30%
Zn - 25-30%
Ni - 40-50%