Facile, low-energy routes for the production of hydrated calcium and magnesium salts from alkaline industrial wastes

Patent metadata

Field	Value
Publication number	US-11560318-B2
Application number	US-201816639503-A
Country	US
Kind code	B2
Filing date	Aug 17, 2018
Priority date	Aug 18, 2017
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

First claim

What is claimed is:

1. A method comprising:
extracting divalent ions from solids by leaching to form a divalent ion-containing solution;
subjecting the divalent ion-containing solution to concentration to form a concentrated divalent ion-containing solution; and
inducing precipitation of a divalent ion hydroxide salt from the concentrated divalent ion-containing solution, wherein subjecting the divalent ion-containing solution to concentration is performed using capacitive concentration.

2. The method of claim 1 , wherein the solids include at least one of (a) slags or (b) fly ashes.

3. The method of claim 1 , wherein extracting the divalent ions from the solids includes exposing the solids to a leaching solution.

4. The method of claim 3 , wherein the leaching solution includes a leaching agent.

5. The method of claim 3 , wherein the leaching solution includes an acid.

6. The method of claim 1 , wherein extracting the divalent ions from the solids includes pulverizing the solids, and exposing the pulverized solids to a leaching solution.

7. The method of claim 1 , wherein subjecting the divalent ion-containing solution to capacitive concentration includes disposing the divalent ion-containing solution between a pair of electrodes, and applying an electrical input to the electrodes.

8. The method of claim 1 , wherein subjecting the divalent ion-containing solution to capacitive concentration includes passing the divalent ion-containing solution through a series of n connected capacitive concentration cells, wherein n is 1 or greater.

9. The method of claim 1 , wherein inducing the precipitation of the divalent ion hydroxide salt includes heating the concentrated divalent ion-containing solution to a temperature at or below 100° C.

10. The method of claim 1 , wherein the divalent ions include calcium ions, and inducing the precipitation of the divalent ion hydroxide salt includes inducing precipitation of portlandite.

11. The method of claim 1 , wherein the divalent ions include magnesium ions, and inducing the precipitation of the divalent ion hydroxide salt includes inducing precipitation of brucite.

Assignees

• Univ California

Inventors

• Sant Gaurav N
• Pilon Laurent G
• La Plante Erika Blanca Callagon
• Wang Bu
• Wei Zongsu
• Castaño Sara Vallejo

Classifications

• C02F1/5236

  using inorganic agents · CPC title

• C01F5/22

  from magnesium compounds with alkali hydroxides or alkaline- earth oxides or hydroxides · CPC title

• Y02P40/18

  Carbon capture and storage [CCS] · CPC title

• C02F2103/06

  Contaminated groundwater or leachate · CPC title

• Y02C20/40

  of CO2 · CPC title