Brine purification process
AssigneeBlue Cube IP LLC
InventorsJianqing Zhou, Kurt Garbade, Sergio Sabater-Prieto, Martin Offermann
Life of this patent
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Abstract
The present invention provides a method for reducing the concentration of aluminum and nickel cations in a brine comprising aluminum and nickel cations. The treated brine can be used as a feedstock to membrane cell chlor-alkali process.
Claims24
A method for reducing the concentration of aluminum and nickel cations in a brine comprising aluminum and nickel cations, the steps of the method comprising:
- a) Determining the pH of the brine and, when the pH of the brine is in excess of 6 or below 2, adjusting the pH of the brine to a pH from 2 through 6;
- and
- b) Contacting the brine of a) with a mixture of at least two cationic exchange resins, wherein the first cationic exchange resin comprises an aminophosphonic acid functional group and the second cationic exchange resin comprises an iminodiacetic acid functional group at a linear liquid velocity from 10 through 100 m/hr, and at a temperature of from 10 through 90° C., to produce a treated brine which contains less aluminum and nickel cations than prior to contacting the brine of a) with the mixture of at least two cationic exchange resins;
- wherein the brine does not contain a chelating or complexing agent, and
- wherein prior to the contact with the mixture of the at least two cationic exchange resins the brine has a concentration of from about 300 ppb to about 5 ppm aluminum and from about 3 ppb to about 100 ppb nickel, and wherein the concentration of aluminum and nickel is reduced to less than about 50 ppb aluminum and to less than about 1 ppb nickel after contact with the mixture of the at least two cationic exchange resins.
A method for reducing the concentration of aluminum and nickel cations in a brine comprising aluminum and nickel cations to provide a brine feedstock used in a membrane cell chlor-alkali process, the steps of the method comprising:
- a) Determining the pH of the brine and, when the pH of the brine is in excess of 6 or below 2, adjusting the pH of the brine to a pH from 2 through 6;
- b) Contacting the brine of a) with a mixture of at least two cationic exchange resins, wherein the first cationic exchange resin comprises an aminophosphonic acid functional group and the second cationic exchange resin comprises an iminodiacetic acid functional group at a liquid velocity from 10 through 100 m/hr, and at a temperature of from 10 through 90° C., to produce a treated brine which contains less aluminum and nickel cations than prior to contacting the brine of a) with the mixture of at least two cationic exchange resins;
- and
- c) Using the brine of b) as a feedstock in a membrane cell chlor-alkali process;
- wherein the brine does not contain a chelating or complexing agent, and
- wherein prior to the contact with the mixture of the at least two cationic exchange resins the brine has a concentration of from about 300 ppb to about 5 ppm aluminum and from about 3 ppb to about 100 ppb nickel, and wherein the concentration of aluminum and nickel is reduced to less than about 50 ppb aluminum and to less than about 1 ppb nickel after contact with the mixture of the at least two cationic exchange resins.
Dependencies are inferred from the claim text.