Talk:FFC Cambridge process

message: Even though I wrote the section on calcium solubility in the melt as opposed to sodium or magnesium, I'm not quite so sure now - does anybody have data? It may be that both sodium and magnesium are quite soluble in their own chloride melts, except they are not strong enough reducers of oxides such as titanium of magnesium to do anything useful. Sillybilly 16:51, 20 June 2006 (UTC)

message: The article says:
"...the electrolysis can be carried out on an insulator oxide, such as zirconia and silica..."
Does this mean oxide materials that are electrically insulating (of which most, if not all, are, including titanium dioxide), or does it mean electrical insulator components used as commercial insulator products?
--Mikiemike (talk) 12:15, 23 February 2008 (UTC)
thread_title: Disambig of "insulator oxide"

message: "There are other difficulties following the “calciothermic reduction” hypothesis. One example is that according to thermodynamic data, Ca cannot reduce Y2O3. However, Y metal was produced by electrolysis of Y2O3 in molten CaCl2 (Wang et al, Angew. Chem. Int. Edit., 45 (2006) 2384-2388.)"
Though I don't have lab measurements or literature references of thermodynamic data, I remember reading that Lanthanum oxide cannot be reduced by metallic calcium, but lanthanum chloride can. If the Y2O3 is slightly dissolved in the chloride into Y ions (whether Y3+, or YO+, or whatever Y2O22+, or whatever highly complex solvated ion forms), the original solid oxide crystalline lattice binding energy will no longer be present. 
Still, one issue in general with this method is the oxygen accumulation in the melt, because at the anode chlorine gas evolves. Fluoride melts, as used for aluminum production, do not build up oxygen. One needs to find a way to drop out oxides, such as cooling the molten calcium chloride to a certain temperature and collecting the oxide precipitate, if it forms. Another method might be carbochlorinating a portion of the melt in a separate container, whereby CaO+CaCl2+C+Cl2 --> CaCl2+Cl2(gas)+CO2(gas). The CO2 can then be separated from the Cl2 and the Cl2 recycled. Note that this method uses stoichiometric amount of C for each oxygen, and renders the process into a carbochlorination one, and one might as well carbochlorinate the initial metal oxide, without dissolving it into a molten salt. This is so unless the carbochlorination reaction rate of the original oxide is extremely slow, and justify using a molten salt, which can attack and react with the oxide at a lower temperature. If dropping out calcium oxide from the melt works, then it can simply be cooled, treated with HCl and dried back to the electrolyte material, CaO+CaCl2+HCl--> CaCl2+H2O. Sillybilly (talk) 00:17, 4 October 2009 (UTC)
replies: text:  Actually, the simplest thing to do is to cool a portion of the melt fully to room temperature (without trying to separate out solid CaO at high temperatures), react it HCl, then dry/reheat the whole thing to reintroduce into the melt.Sillybilly (talk) 18:42, 4 October 2009 (UTC)
thread_title:  Calcium cannot reduce Yttrium 

message: Moved from the article. Comments? Materialscientist (talk) 12:32, 27 March 2011 (UTC)
thread_title: Was the process known decades ago?

message: This process has proposed for metal production from regolith on Moon and Mars.  Some estimates of the energy requirements, and any consumables like electrodes would be interesting. - Rod57 (talk) 13:49, 12 November 2020 (UTC)
thread_title:  Proposed for use on Moon and Mars