Revision Snapshot: High-Speed Summary

Ore vs mineral: Ore = economically extractable; mineral = naturally occurring compound
Concentration: Sulphide → froth flotation; Oxide (dense) → hydraulic; Magnetic → magnetic separation; Au → NaCN leaching; Al2O3 → NaOH (Bayer's)
Calcination: Limited air + carbonate/hydrated ores → oxide + CO2/H2O
Roasting: Excess air + sulphide ores → oxide + SO2
Ellingham: Lower line = more stable oxide = better reducing agent; C→CO slopes down ( $\Delta S$ > 0)
Al extraction: Bayer's process (NaOH) → Hall-Heroult (electrolysis, cryolite lowers mp from 2072°C to 950°C)
Carbon anodes in Hall-Heroult are consumed (C + $O^{2-}$ → CO2)
Cu extraction: CuFeS2 → froth float → roast → matte (Cu2S + FeS) → Bessemer → blister Cu (98%) → electrolytic refining
Self-reduction: Cu2S + 2Cu2O → 6Cu + SO2 (no external reductant)
Blister copper: ~98% pure; blistered by escaping SO2
Anode mud: Au, Ag (less electropositive — do NOT dissolve at anode)
Zone refining: Si, Ge, Ga; impurities prefer melt (k < 1); movable heater
Mond process: Ni + 4CO → Ni(CO)4 at 330–350 K; decompose at 450–470 K
Van Arkel: Ti + 2I2 → TiI4 at ~870 K; decompose on W filament at ~1700 K
Blast furnace: Fe2O3 + 3CO → 2Fe + 3CO2 at 500–800 K; slag = CaSiO3 from CaO + SiO2

Process	Reaction
Gold leaching	$4Au + 8NaCN + 2H_2O + O_2 \rightarrow 4Na[Au(CN)_2] + 4NaOH$
ZnS depressant	$ZnS + 4NaCN \rightarrow Na_2[Zn(CN)_4] + Na_2S$
Roasting ZnS	$2ZnS + 3O_2 \rightarrow 2ZnO + 2SO_2$
Fe2O3 reduction	$Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2$
Slag formation	$CaO + SiO_2 \rightarrow CaSiO_3$
Cu self-reduction	$Cu_2S + 2Cu_2O \rightarrow 6Cu + SO_2$
Hall-Heroult cathode	$$$Al^{3+}$ + 3e^- \rightarrow Al$$
Hall-Heroult anode	$C + 2$O^{2-}$ \rightarrow CO_2 + 4e^-$
Mond (Ni)	$Ni + 4CO \rightleftharpoons Ni(CO)_4$
Van Arkel (Ti)	$Ti + 2I_2 \rightleftharpoons TiI_4$