Compositions for use in geosynthetic liners

Patent metadata

Field	Value
Publication number	US-2020039881-A1
Application number	US-201716470017-A
Country	US
Kind code	A1
Filing date	Dec 18, 2017
Priority date	Dec 16, 2016
Publication date	Feb 6, 2020
Grant date	—

Abstract

Described herein is a composition for use in a geosynthetic clay liner, the composition comprising particles, at least some of which are discrete particles and each comprise: a compacted swelling clay, the clay having been compacted such that it at least partially surrounds a fluid-loss preventing polymer. Also described herein is a clay liner formed from the composition, a method for producing particles for use in a geosynthetic clay liner, and a method of forming a clay liner.

First claim

1 . A method for producing particles for use in a geosynthetic clay liner, the method comprising:
dry mixing first particles comprising a swelling clay and second particles comprising a fluid-loss preventing polymer, compacting the dry mixed first and second particles to form one or more compacted bodies, crushing the one or more compacted bodies to form discrete particles for use in a geosynthetic liner, at least some of the discrete particles comprising the swelling clay and the fluid-loss preventing polymer, wherein at least some of the fluid-loss preventing polymer is at least partially surrounded by the swelling clay.

2 . A method as claimed in claim 1 , wherein the swelling clay comprises a material selected from a smectite clay and a vermiculite clay.

3 . A method as claimed in claim 2 , wherein the smectite clay comprises a material selected from montmorillonite, beidellite, nontronite, hectorite, saponite, sauconite and laponite.

4 . A method as claimed in claim 2 , wherein the smectite clay comprises a bentonite.

5 . A method as claimed in any one of the preceding claims, wherein the fluid-loss preventing polymer is selected from an anionic polymer, a non-ionic polymer and a cationic polymer.

6 . A method as claimed in any one of the preceding claims, wherein the fluid-loss preventing polymer comprises an anionic polymer.

7 . A method as claimed in any one of the preceding claims, wherein the fluid-loss preventing polymer comprises a polyanionic cellulose.

8 . A method as claimed in any one of the preceding claims, wherein at least 90 wt % of the first particles, before they are dry mixed with the second particles, pass through a sieve having openings of 1.5 mm or less.

9 . A method as claimed in any one of the preceding claims, wherein at least 90 wt % of the first particles, before they are dry mixed with the second particles, pass through a sieve having openings of 1.0 mm or less.

10 . A method as claimed in any one of the preceding claims, wherein at least 90 wt % of the first particles, before they are dry mixed with the second particles, pass through a sieve having openings of 0.8 mm or less.

11 . A method as claimed in any one of the preceding claims, wherein the first particles have a moisture content of at least 5 wt %.

12 . A method as claimed in any one of the preceding claims, wherein the fluid-loss preventing polymer constitutes from 0.5 wt % to 10 wt % of the mixture of first and second particles.

13 . A method as claimed in any one of the preceding claims, wherein compacting the dry mixed first and second particles to form one or more compacted bodies involves passing the first and second particles through a compactor that applies a pressure of at least 3.45×10 6 Pa (500 psi) to the particles.

14 . A method as claimed in any one of the preceding claims, wherein compacting the dry mixed first and second particles to form one or more compacted bodies involves passing the first and second particles through a compactor that applies a pressure of at least 6.89×10 6 Pa (1000 psi) to the particles.

15 . A method as claimed in any one of the preceding claims, wherein compacting the dry mixed first and second particles to form one or more compacted bodies involves passing the first and second particles through a compactor that applies a pressure of from 9.65×10 6 Pa (1400 psi) to 1.17×10 7 Pa (1700 psi) to the particles.

16 . A method as claimed in any one of the preceding claims, wherein the compactor processes at least 0.5 mt of the first and second particles per hour (at least 1.5 mt, at least 1.7 Mt).

17 . A method as claimed in any one of the preceding claims, wherein the crushing the one or more compacted bodies to form discrete particles results in the discrete particles, at least some of which have a particle size of from 0.2 mm to 3 mm.

18 . A method as claimed in any one of the preceding claims, wherein the crushing the one or more compacted bodies to form discrete particles results in the discrete particles, at least some of which have a particle size of from 0.5 mm to 2 mm.

19 . A method as claimed in any one of the preceding claims, wherein the crushing forms discrete particles, which are then sieved such that at least 90 wt % of the discrete particles pass through a sieve with openings of 3 mm.

20 . A method as claimed in any one of the preceding claims, wherein the crushing forms discrete particles, which are then sieved such that at least 90 wt % of the discrete particles are retained on a sieve with openings of 0.2 mm.

21 . A method as claimed in any one of the preceding claims, wherein the crushing forms discrete particles, which are then sieved such that at least 90 wt % of the discrete particles pass through a sieve with openings of 2 mm.

22 . A method as claimed in any one of the preceding claims, wherein, the crushing forms discrete particles, which are then sieved such that at least 90 wt % of the discrete particles are retained on a sieve with openings of 0.5 mm.

23 . A method as claimed in any one of the preceding claims, wherein, after the crushing, the discrete particles are separated into at least two samples having different size distributions: a first sample and a second sample, and, if the second sample contains larger particles than the first sample, particles from the second sample are re-processed to reduce their size or if the second sample contains smaller particles than the first sample, particles of the second sample are re-compacted to form one or more further compacted bodies, which are then re-crushed to form discrete particles with larger particles than the second sample.

24 . A composition for use in a geosynthetic clay liner, the composition comprising particles, at least some of which are discrete particles and each comprise:
a compacted swelling clay, the clay having been compacted such that it at least partially surrounds a fluid-loss preventing polymer.

25 . A composition according to claim 24 , wherein at least some of the discrete particles have a particle size of from 0.2 mm to 3 mm.

26 . A composition according to claim 24 , wherein at least some of the discrete particles have a particle size of from 0.5 mm to 2 mm.

27 . A composition according to any one of claims 24 to 26 , wherein at least 90 wt % of the discrete particles pass through a sieve with openings of 3 mm.

28 . A composition according to any one of claims 24 to 27 , wherein at least 90 wt % of the discrete particles are retained on a sieve with openings of 0.2 mm.

29 . A composition according to any one of claims 24 to 28 , wherein at least 90 wt % of the discrete particles pass through a sieve with openings of 2 mm.

30 . A composition according to any one of claims 24 to 29 , wherein at least 90 wt % of the discrete particles are retained on a sieve with openings of 0.5 mm.

31 . A composition according to any one of claims 24 to 30 , wherein the swelling clay comprises a material selected from a smectite clay and a vermiculite clay.

32 . A composition according to claim 31 , wherein the smectite clay comprises a material selected from montmorillonite, beidellite, nontronite, hectorite, saponite, sauconite and laponite.

33 . A composition according to claim 31 , wherein the smectite clay compr

Assignees

• Imertech Sas

Inventors

• Dedeloudis Christos
• Zervaki Monika
• Belev Anton
• Kapralou Christina

Classifications

• C04B24/383

  Cellulose or derivatives thereof · 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

• E02D31/006 Primary

  Sealing of existing landfills, e.g. using mining techniques · CPC title

• C04B14/18

  Perlite · CPC title

• C04B2111/00612

  as one or more layers of a layered structure · CPC title