Salt production via hydrohalite decomposition

Patent metadata

Field	Value
Publication number	US-11932551-B2
Application number	US-202017039481-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Oct 24, 2019
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

Salt production can include preparing hydrohalite particles by crystallization from saturated brine, adding the hydrohalite particles to a salt brine, thereby forming a hydrohalite-salt brine mixture, agitating the hydrohalite-salt brine mixture until the hydrohalite particles have decomposed into NaCl crystals, and filtering out the NaCl crystals from the salt brine. In some instances, an initial temperature of the salt brine prior to adding the hydrohalite particles is at least 0° C. In some instances, a ratio of salt brine to hydrohalite particles, by weight, is from 0.4 to 29.

First claim

What is claimed is:

1. A method for producing salt, the method comprising:
preparing hydrohalite particles by crystallization from saturated brine;
adding the hydrohalite particles to a salt brine, thereby forming a hydrohalite-salt brine mixture,
wherein an initial temperature of the salt brine prior to adding the hydrohalite particles is sufficient to decompose the hydrohalite particles without external heating;
wherein the initial temperature of the salt brine prior to adding the hydrohalite particles is between 0° C. and 40° C.; and
wherein a ratio of salt brine to hydrohalite particles, by weight, is from 0.4 to 29;

agitating the hydrohalite-salt brine mixture until the hydrohalite particles have decomposed into NaCl crystals; and
filtering out the NaCl crystals from the salt brine.

2. The method according to claim 1 , wherein after agitating the hydrohalite-salt brine mixture, the salt brine has a lower temperature than the initial temperature, and further comprising:
transferring the salt brine at the lower temperature to a crystallizer to generate additional hydrohalite particles.

3. The method according to claim 1 , wherein the initial temperature of the salt brine is no greater than 37° C.

4. The method according to claim 1 , wherein preparing the hydrohalite particles by crystallization occurs at a temperature of no less than −20° C. and no more than −8° C.

5. The method according to claim 1 , wherein the hydrohalite particles decompose during agitation in less than 10 minutes.

6. The method according to claim 1 , wherein a time between starting agitating the hydrohalite-salt brine mixture and starting filtering out the NaCl crystals is less than 24 hours.

7. The method according to claim 1 , wherein filtering out the NaCl crystals includes using vacuum filtration.

8. The method according to claim 1 , wherein a mean particle size of the NaCl crystals is less than 150 μm.

9. The method according to claim 8 , wherein a purity of the NaCl crystals is at least 99.8%.

10. A method for producing salt, the method comprising:
preparing hydrohalite particles by crystallization from saturated brine;
adding the hydrohalite particles to a salt brine, thereby forming a hydrohalite-salt brine mixture,
wherein an initial temperature of the salt brine prior to adding the hydrohalite particles is between 0° C. and 40° C.; and
when the initial temperature of the salt brine is between 5° C. and 10° C., a ratio of salt brine to hydrohalite particles, by weight, is from 4.5 to 29;
when the initial temperature of the salt brine is between 10° C. and 15° C., the ratio of salt brine to hydrohalite particles, by weight, is from 2.5 to 4.8;
when the initial temperature of the salt brine is between 15° C. and 20° C., the ratio of salt brine to hydrohalite particles, by weight, is from 1.7 to 2.7;
when the initial temperature of the salt brine is between 20° C. and 25° C., the ratio of salt brine to hydrohalite particles, by weight, is from 1.3 to 1.8;
when the initial temperature of the salt brine is between 25° C. and 30° C., the ratio of salt brine to hydrohalite particles, by weight, is from 1.0 to 1.4; and
when the initial temperature of the salt brine is between 30° C. and 40° C., the ratio of salt brine to hydrohalite particles, by weight, is from 0.4 to 1.2;

agitating the hydrohalite-salt brine mixture until the hydrohalite particles have decomposed into NaCl crystals; and
filtering out the NaCl crystals from the salt brine.

Assignees

• Univ Michigan Tech

Inventors

• Eisele Tim

Classifications

• C01D3/06 Primary

  Preparation by working up brines; seawater or spent lyes · CPC title

• C01B6/34

  Purification; Stabilisation · CPC title

• C01B9/02

  Chlorides · CPC title

• C01D3/14

  Purification · CPC title

• C01P2004/60

  Particles characterised by their size · CPC title