Sea salt: Difference between revisions
Jump to navigation
Jump to search
JeffEvarts (talk | contribs) No edit summary |
JeffEvarts (talk | contribs) No edit summary |
||
Line 1: | Line 1: | ||
{| style='float:right;' class="wikitable sortable" | {| style='float:right;' class="wikitable sortable" | ||
|+Dissolved ions in seawater over | |+Dissolved ions in seawater over 50mg/L | ||
! | !Cation | ||
!Molarity | !Molarity | ||
! | !Anion | ||
|- | |- | ||
| ||0.535||[[Chlorine|Cl<sup>-</sup>]] | | ||0.535||[[Chlorine|Cl<sup>-</sup>]] | ||
Line 22: | Line 22: | ||
|} | |} | ||
__TOC__ | __TOC__ | ||
[[Salt water|Seawater]] contains just about every element in ''some'' small quantity. The materials over 50mg/L is a shorter list.{{br}} | |||
[[Salt water|Seawater]] contains just about every element in ''some'' small quantity. The materials over | |||
==Character== | ==Character== | ||
For seawater and many brines, the order of deposition is:<ref>{{cite pub | For seawater and many brines, the order of deposition is:<ref>{{cite pub |
Revision as of 20:46, 23 December 2019
Cation | Molarity | Anion |
---|---|---|
0.535 | Cl- | |
Na+ | 0.459 | |
0.009 | SO4 | |
Mg2+ | 0.051 | |
Ca2+ | 0.009 | |
K+ | 0.009 | |
0.002 | HCO3- | |
0.00082 | Br- |
Seawater contains just about every element in some small quantity. The materials over 50mg/L is a shorter list.
Character
For seawater and many brines, the order of deposition is:[1]
- calcium carbonate
- calcium sulfate
- sodium chloride
- magnesium sulfate
- potassium magnesium chloride hexahydrate (KCl•MgCl2•6H2O)
- magnesium chloride
Purification
Removal of sulfate and bicarbonate
To remove the 0.011 mol of these, add a small amount soluble calcium. (0.5g/L calcium oxide or 0.75g/L of calcium hydroxide) This will cause calcium carbonate and calcium sulfate to precipitate.
- CaO + NaHCO3 → CaCO3 + NaOH
- Ca(OH)2 + NaHCO3 → CaCO3 + NaOH + H2O
- CaO + Na2SO4 + H2O → CaSO4 + 2 NaOH
- Ca(OH)2 + Na2SO4 → CaSO4 + 2 NaOH
Removal of calcium and magnesium
With Calcium and Magnesium combined for 0.06 mol/L, adding 0.06mol of soluble ash (7-8g/L) should precipitate most of the alkali earth metal content.
- (Ca/Mg)Cl2(aq) + (Na/K)2CO3(aq) → (Ca/Mg)CO3(s) + 2 (Na/K)Cl(aq)
This leaves sodium/potassium chloride/sulfate/carbonate in solution, which can be more easily separated by crystallization
See Also
References
- ↑ Hills, John M.; Wood, Frank Osborne (2019) "Salt: Salt Manufacture"
Encyclopedia Britannica
link courtesy Encyclopedia Britannica.