This process is used to produce Aluminium from Alumina. It also is what GregTech 6 uses. The theory behind it is that AlF3 and Cryolite both significantly lower melting points in a molten solution, so electrolysis becomes significantly easier to perform.
Products
Main Product: Alumina
Side Product(s): None
Steps
3 Fluorite (s) + 1 Sulfuric Acid (aq) -> 6 Calcium Sulfate (s) + 2 Hydrofluoric Acid (aq)
CaF2 (s) + H2SO4 (aq) -> CaSO4 (s) + 2HF (aq)
This should be done in the chemical bath.
3 Silicon Dioxide (s) + 6 Hydrofluoric Acid (aq) -> 1 Hexafluorosilicic Acid (aq) + 2 Water (l)
SiO2 (s) + 6HF (aq) -> H2SiF6 (aq) + 2H2O (l)
5 Alumina (s) + 1 Hexafluorosilicic Acid (aq) -> 8 Aluminium Fluoride (s) + 3 Silicon Dioxide (s) + Water (l)
Al2O3 (s) + H2SiF6 (aq) -> 2AlF3 (s) + SiO2 (s) + H2O (l)
This reaction occurs at 973K.
1 Aluminium Fluoride (s) -> 144L Aluminium Fluoride (l) at 1560K.
5 Alumina (s) + 18 Sodium Hydroxide (s) + 12 Hydrofluoric Acid (aq) -> 20 Cryolite Dust (s) + 6 Water (l) + 3 Oxygen (g).
Al2O3 (s) + 6NaOH (s) + 12HF (aq) -> 2Na3AlF6 (s) + 6H2O (l) + 3O (g)
The oxygen can be lost in this step.
1 Cryolite (s) -> 144L Cryolite (l) at 1285K.
10 Alumina (s) + 3 Carbon (s) + 4L Aluminium Fluoride (l) + 2L Cryolite (l) -> 4 Aluminium Dust (s) + 3 Carbon Dioxide (g) + 29L Fluorine (g)
2Al2O3 (s) + 3C (s) -> 4Al (s) + 3CO2 (g)
This step is done in an electrolyzer. The amounts of Aluminium Fluoride and Cryolite are the values used by mass IRL.
Yield
5 Alumina -> 2 Aluminium
Note that 1 batch of Aluminium Fluoride is good for 288 electrolyzer steps, and a batch of Cryolite is good for 1440 steps.
Details
This process is used to produce Aluminium from Alumina. It also is what GregTech 6 uses. The theory behind it is that AlF3 and Cryolite both significantly lower melting points in a molten solution, so electrolysis becomes significantly easier to perform.
Products
Main Product: Alumina Side Product(s): None
Steps
3 Fluorite (s) + 1 Sulfuric Acid (aq) -> 6 Calcium Sulfate (s) + 2 Hydrofluoric Acid (aq)
CaF2 (s) + H2SO4 (aq) -> CaSO4 (s) + 2HF (aq)This should be done in the chemical bath.3 Silicon Dioxide (s) + 6 Hydrofluoric Acid (aq) -> 1 Hexafluorosilicic Acid (aq) + 2 Water (l)
SiO2 (s) + 6HF (aq) -> H2SiF6 (aq) + 2H2O (l)5 Alumina (s) + 1 Hexafluorosilicic Acid (aq) -> 8 Aluminium Fluoride (s) + 3 Silicon Dioxide (s) + Water (l)
Al2O3 (s) + H2SiF6 (aq) -> 2AlF3 (s) + SiO2 (s) + H2O (l)This reaction occurs at 973K.1 Aluminium Fluoride (s) -> 144L Aluminium Fluoride (l) at 1560K.
5 Alumina (s) + 18 Sodium Hydroxide (s) + 12 Hydrofluoric Acid (aq) -> 20 Cryolite Dust (s) + 6 Water (l) + 3 Oxygen (g).
Al2O3 (s) + 6NaOH (s) + 12HF (aq) -> 2Na3AlF6 (s) + 6H2O (l) + 3O (g)The oxygen can be lost in this step.1 Cryolite (s) -> 144L Cryolite (l) at 1285K.
10 Alumina (s) + 3 Carbon (s) + 4L Aluminium Fluoride (l) + 2L Cryolite (l) -> 4 Aluminium Dust (s) + 3 Carbon Dioxide (g) + 29L Fluorine (g)
2Al2O3 (s) + 3C (s) -> 4Al (s) + 3CO2 (g)This step is done in an electrolyzer. The amounts of Aluminium Fluoride and Cryolite are the values used by mass IRL.Yield
5 Alumina -> 2 Aluminium Note that 1 batch of Aluminium Fluoride is good for 288 electrolyzer steps, and a batch of Cryolite is good for 1440 steps.
Sources
GregTech 6 https://en.wikipedia.org/wiki/Hall%E2%80%93H%C3%A9roult_process https://en.wikipedia.org/wiki/Aluminium_fluoride https://en.wikipedia.org/wiki/Hexafluorosilicic_acid https://en.wikipedia.org/wiki/Cryolite