123 - 30-12-2006 at 02:03
I have an aqueous solution (200 gpm) with the following composition (mg/L):
- Ca2+ 8700
- Na+ 160
- Mg2+ 1800
- Cl- 15000
- SO4- 3500
Can I do anything useful or sell the mixture of salts we obtain by evaporation-crystallization?
Thanks.
guy - 30-12-2006 at 02:31
Seriously?
Dr. Beaker - 30-12-2006 at 11:26
lol
I have unlimited amounts of a mixture of gases with the following composition:
Nitrogen 78%
Oxygen 21 %
Argon 1%
Carbon Dioxide CO2 traces
I'm going to sell it on ebay
UnintentionalChaos - 30-12-2006 at 12:47
That mixture sounds quite like de-icing salts (except for the sulfate). Use it on your driveway or sidewalk in winter (if you get icy conditions).
"I have unlimited amounts of a mixture of gases with the following composition:
Nitrogen 78%
Oxygen 21 %
Argon 1%
Carbon Dioxide CO2 traces"
WOW What a coincidence, I have the exact same mixture!!!
UnintentionalChaos - 30-12-2006 at 13:25
Ok...well as pointless as this post seemed to be, I felt like I should be able to answer this question, so I did some quick research. I assume all of
the sulfate has precipitated out at calcium sulfate (it has extremely low solubility), so by removing that, you are left with a mixture of 3
chlorides, all of which make good road de-icers. Alternately, you could heat the mix until it is anhydrous and use it as a dessicant, since it would
be a large proportion of CaCl2. If you for some reason wanted to get rid of the sodium chloride, you could use alcohol or acetone to dissolve the
MgCl2 and CaCl2. This could then be dried and redisoolved in water. A stoichiometric amount of sodium sulfate (glauber's salt, easily made by reacting
epsom salts with NaOH drain cleaner, draining off, and dehydrating the liquid) could be added to precipitate calcium sulfate (gypsum or plaster of
paris) and leave MgCl2 and more NaCl in solution. Again, drying and alcohol dissolution could recover fairly pure magnesium chloride, though I am not
sure what you'd need that for unless you plan on doing molten salt electrolysis in a vacuum for Mg metal and Cl2 or using it as a coagulant to make
tofu (Nigari is mainly MgCl2). of course, this is all completely economically infeasible and a serious waste of time, unless you would just enjoy the
process (I enjoy this kind of challenge).
12AX7 - 30-12-2006 at 18:40
The CaSO4 would come out first, but it most likely is in solution. It's very slightly soluble. Remember those are ppm values. It also tends to
crystallize slowly so may indeed be supersaturated with it but not crystallizing just yet.
Tim
123 - 31-12-2006 at 00:57
Thanks. I'm doing a project about a ZLD system of a FGD wastewater stream. I've decided to use evaporation-crystallization. I've found out that in
some cases we take the cake (mixture of salts) for disposal but sometimes we can separate the mixture ( CaSO4 + chlorides would be an option, thaks
UnintentionalChaos) in order to improve the economic matter. Maybe it's a chemical engineering subject but if you have any information please tell me.
Thanks.