Making mineral salts from various sources
Hydrometallurgical systems, methods, and compositions are described in which organic amine-based lixiviants are utilized in the selective recovery of alkaline earth elements. The lixiviant can be regenerated and recycled for use in subsequent iterations of the process. Multiple alkaline earth elements can be recovered from a sample in parallel or in serial applications of the disclosed methods.
1. A mixture utilized in lixiviant extraction of a metal hydroxide forming species from a raw material comprising:
a raw material comprising an insoluble metal salt, wherein the insoluble metal salt comprises the metal hydroxide forming species; and
a lixiviant solution comprising an organic amine cation and a counterion,
wherein the lixiviant solution is formulated to transfer the counterion to the insoluble metal salt to form an uncharged organic amine, and wherein the uncharged organic amine is formulated to react with an acid to regenerate the organic amine cation, and
wherein the organic amine cation is present in a substoichiometric amount relative to the insoluble metal salt.
2. The mixture of claim 1 , wherein the organic amine has a vapor pressure less than about 1% that of ammonia.
3. The mixture of claim 1 , wherein the organic amine has a vapor pressure less than about 0.1% that of ammonia.
4. The lixiviant mixture of claim 1 , wherein the organic amine has a pKa between 8 and 14.
5. The mixture of claim 1 , wherein the organic amine cation is obtained from a biological source.
6. The mixture of claim 1 , wherein the counterion has a pKa between 1 and 6.
7. The mixture of claim 1 , wherein the counterion is selected from the group consisting of halides, anions derived from mineral acids, anions derived from organic acids, anions derived from organic molecules, anions derived from biomolecules, zwitterions, and basic synthetic polymers.
8. The mixture of claim 1 , wherein the organic amine cation is selected from the group consisting of nitrogen containing organic compounds, low molecular weight biological molecules, biomolecule polymers, dendritic polyamines, and polycationic polymeric or oligomeric materials.
9. The mixture of claim 1 , comprising a zwitterionic species that can act as both an organic amine cation and a counterion.
10. The mixture of claim 1 , wherein the insoluble metal salt is present in a molar ratio of greater than 2 relative to the organic amine cation.
11. The mixture of claim 1 , wherein the insoluble metal salt is present in a molar ratio of greater than 5 relative to the organic amine cation.
12. The mixture of claim 1 , wherein the insoluble metal salt is present in a molar ratio of greater than 10 relative to the organic amine cation.