Modified sodium bentonite clays for barrier layer applications

Patent metadata

Field	Value
Publication number	US-2019039950-A1
Application number	US-201515760217-A
Country	US
Kind code	A1
Filing date	Oct 16, 2015
Priority date	Oct 16, 2015
Publication date	Feb 7, 2019
Grant date	—

Abstract

The permeability of barrier layers formed from sodium bentonite clay may be significantly and unpredictably impacted upon contacting various ionic substances. Modifying agents may be admixed with sodium bentonite clay to lessen the impacts resulting from its contact with an ionic substance. Suitable modifying agents may comprise an anionic substance selected from the group consisting of a diutan, a polymer containing a 2-acrylamido-2-methylpropanesulfonic acid monomer, any salt thereof, and any combination thereof. Methods for forming a barrier layer may comprise: providing a barrier material comprising sodium bentonite clay and a modifying agent admixed with the sodium bentonite clay, the modifying agent comprising an anionic substance selected from the group consisting of a diutan, a polymer containing a 2-acrylamido-2-methylpropanesulfonic acid monomer, any salt thereof, and any combination thereof; and forming a barrier layer comprising the barrier material.

First claim

The invention claimed is:

1 . A barrier material comprising:
sodium bentonite clay; and a modifying agent admixed with the sodium bentonite clay, the modifying agent comprising an anionic substance selected from the group consisting of a diutan, a polymer containing a 2-acrylamido-2-methylpropanesulfonic acid monomer, any salt thereof, and any combination thereof.

2 . The barrier material of claim 1 , wherein the sodium bentonite clay has a d 90 between about 6 mesh and about 60 mesh.

3 . The barrier material of claim 1 , wherein the modifying agent comprises a copolymer of 2-acrylamido-2-methylpropanesulfonic acid and acrylamide.

4 . The barrier material of claim 1 , wherein the modifying agent comprises a copolymer of 2-acrylamido-2-methylpropanesulfonic acid, acrylamide and acrylic acid.

5 . The barrier material of claim 1 , wherein the modifying agent comprises a copolymer of 2-acrylamido-2-methylpropanesulfonic acid, acrylamide and 2-vinylpyrollidone.

6 . The barrier material of claim 1 , wherein the modifying agent further comprises an inorganic base.

7 . The barrier material of claim 6 , wherein the inorganic base comprises sodium carbonate.

8 . The barrier material of claim 1 , wherein the barrier material comprises about 0.1 wt. % to about 15 wt. % of the modifying agent.

9 . The barrier material of claim 1 , further comprising:
a first geosynthetic layer and a second geosynthetic layer, the sodium bentonite clay and the modifying agent being sandwiched between the first geosynthetic layer and the second geosynthetic layer.

10 . The barrier material of claim 9 , wherein the first geosynthetic layer and the second geosynthetic layer are independently selected from the group consisting of a fabric and a geomembrane.

11 . The barrier material of claim 9 , wherein the sodium bentonite clay and the modifying agent are adhesively or mechanically bonded to at least one of the first geosynthetic layer or the second geosynthetic layer.

12 . The barrier material of claim 9 , further comprising:
a geofilm intervening between the sodium bentonite clay and at least one of the first geosynthetic layer or the second geosynthetic layer.

13 . The barrier material of claim 1 , further comprising:
a geomembrane to which the sodium bentonite clay and the modifying agent are adhesively bonded.

14 . A method comprising:
providing a barrier material comprising sodium bentonite clay and a modifying agent admixed with the sodium bentonite clay, the modifying agent comprising an anionic substance selected from the group consisting of a diutan, a polymer containing a 2-acrylamido-2-methylpropanesulfonic acid monomer, any salt thereof, and any combination thereof; and forming a barrier layer comprising the barrier material.

15 . The method of claim 14 , further comprising:
mixing the sodium bentonite clay and the modifying agent together to form the barrier material.

16 . The method of claim 14 , wherein forming the barrier layer comprises compacting the barrier material upon soil, or forming a soil mixture comprising the barrier material and compacting the soil mixture.

17 . The method of claim 14 , wherein forming the barrier layer comprises applying a geosynthetic clay liner to a surface, the geosynthetic clay liner comprising a first geosynthetic layer and a second geosynthetic layer, the sodium bentonite clay and the modifying agent being sandwiched between the first geosynthetic layer and the second geosynthetic layer.

18 . The method of claim 17 , wherein the first geosynthetic layer and the second geosynthetic layer are independently selected from the group consisting of a fabric and a geomembrane.

19 . The method of claim 14 , wherein forming the barrier layer comprises applying a geosynthetic clay liner to a surface, the geosynthetic clay liner comprising a geomembrane to which the sodium bentonite clay and the modifying agent are adhesively bonded.

20 . The method of claim 14 , wherein the barrier layer comprises a portion of a pond, a reservoir, a landfill, a mining site, a fly ash repository site, or coal ash repository site.

21 . The method of claim 14 , further comprising:
contacting a leachate with the barrier layer, the leachate comprising an ionic substance.

22 . The method of claim 21 , wherein the leachate comprises at least one ionic substance selected from the group consisting of potassium ions, calcium ions, magnesium ions, iron ions, aluminum ions, zirconium ions, lead ions, cobalt ions, copper ions, tin ions, silver ions, fluoride ions, chloride ions, bromide ions, sulfate ions, and any combination thereof.

Assignees

• Halliburton Energy Services Inc

Inventors

• May Preston Andrew
• Collins Ryan Patrick

Classifications

• E02D31/004

  Sealing liners · CPC title

• C04B14/104 Primary

  Bentonite, e.g. montmorillonite · CPC title

• C04B22/10

  containing carbon in the anion, e.g. carbonates · CPC title

• C04B2111/00775

  the composition being used as waste barriers or the like, e.g. compositions used for waste disposal purposes only, but not containing the waste itself · CPC title

• C04B24/38

  Polysaccharides or derivatives thereof {(C04B24/243 takes precedence)} · CPC title