Method and system for extraction of minerals based on divalent cations from brine
A system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.
1. A system for production of minerals from divalent ion-containing brine, comprising:
a first nanofiltration seawater reverse osmosis (NF-SWRO) membrane unit configured to receive a divalent-ion rich reject stream and to reject sulfate while allowing divalent ions to pass into a first permeate stream;
a first concentration unit configured to receive the first permeate stream and produce solid calcium sulfate dihydrate and a magnesium-rich brine stream;
a second concentration unit configured to receive and concentrate the magnesium-rich brine stream to a saturation point of sodium chloride;
a first crystallizing unit configured to receive the concentrated magnesium-rich brine stream and produce solid sodium chloride and a supernatant product stream;
a third concentration unit configured to receive the supernatant product stream and produce a concentrated magnesium-rich bittern stream; and
at least one of
a second crystallizing unit configured to dry the concentrated magnesium-rich bittern stream and produce hydrated magnesium chloride, and
a dry air process unit configured to prill the concentrated magnesium-rich bittern stream under a hydrogen chloride atmosphere to produce anhydrous magnesium chloride.
2. The system for production of minerals from divalent ion-containing brine of claim 1 , further comprising:
a polishing unit configured to receive the first permeate stream and reduce a molar ratio of sodium to magnesium in the permeate stream to one or below.
3. The system for production of minerals from divalent ion-containing brine of claim 2 , wherein the polishing unit is a second NF-SWRO unit.
4. The system for production of minerals from divalent ion-containing brine of claim 1 , further comprising:
a clarifying unit configured to reduce sulfate in the magnesium-rich brine stream prior to entry of the magnesium-rich brine stream into the second concentration unit.
5. The system for production of minerals from divalent ion-containing brine of claim 3 , further comprising:
a clarifying unit configured to reduce sulfate in the magnesium-rich brine stream prior to entry of the magnesium-rich brine stream into the second concentration unit.
6. The system for production of minerals from divalent ion-containing brine of claim 4 , wherein
the clarifying unit is configured to reduce sulfate by precipitating a sulfate salt using a soluble salt of an alkaline earth metal.
7. The system for production of minerals from divalent ion-containing brine of claim 5 , wherein
the clarifying unit is configured to reduce sulfate by use of a soluble salt of an alkaline earth metal to precipitate sulfate salt.
8. The system for production of minerals from divalent ion-containing brine of claim 1 , wherein
the first concentration unit is a combination membrane crystallizer/brine concentrator.
9. The system for production of minerals from divalent ion-containing brine of claim 1 , wherein
the first concentration unit is a membrane crystallizer.
10. The system for production of minerals from divalent ion-containing brine of claim 1 , wherein
the second concentration unit is a first solar concentration pond, a first thermal process, or a first membrane process.
11. The system for production of minerals from divalent ion-containing brine of claim 1 , wherein
the third concentration unit is a second solar concentration pond, a second thermal process, or a second membrane process.
12. The system for production of minerals from divalent ion-containing brine of claim 1 , wherein
the second crystallizing unit is a third thermal process or a third membrane process.
13. A method of producing minerals from divalent ion-containing brine, comprising the steps of:
rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit;
producing solid calcium sulfate dihydrate and a magnesium-rich brine stream from the first permeate stream using a first concentration unit;
concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit;
producing solid sodium chloride and a supernatant product stream from the concentrated magnesium-rich brine stream in a first crystallizing unit;
produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit; and
at least one of
producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit, and
producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bittern stream under a hydrogen chloride atmosphere using a dry air process unit.
14. The method of producing minerals from divalent ion-containing brine of claim 13 , further comprising the step of:
reducing a molar ratio of sodium to magnesium in the permeate stream to one or below in a polishing unit.
15. The method of producing minerals from divalent ion-containing brine of claim 14 , wherein the polishing unit is a second NF-SWRO unit.
16. The method of producing minerals from divalent ion-containing brine of claim 13 , further comprising the step of:
reducing sulfate in the magnesium-rich brine stream in a clarifying unit prior to entry of the magnesium-rich brine stream into the second concentration unit.
17. The method of producing minerals from divalent ion-containing brine of claim 15 , further comprising the step of:
reducing sulfate in the magnesium-rich brine stream in a clarifying unit prior to entry of the magnesium-rich brine stream into the second concentration unit.
18. The method of producing minerals from divalent ion-containing brine of claim 16 , wherein the step of reducing sulfate in the magnesium-rich brine stream in a clarifying unit includes precipitating a sulfate salt using a soluble salt of an alkaline earth metal.
19. The method of producing minerals from divalent ion-containing brine of claim 17 , wherein the step of reducing sulfate in the magnesium-rich brine stream in a clarifying unit includes precipitating a sulfate salt using a soluble salt of an alkaline earth metal.