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.

The invention relates to a low-permeability geotechnical barrier material including a blend of approximately equal parts of: aggregate particles, sand-size particles and manufactured composite particles that include a hydratable sealant material composed of naturally-occurring clay minerals and/or polymer-enhanced clay minerals, such that the actual percentage of clay mineral component is less than 10% by weight in the blended material. In a particular embodiment, the construction of a low-permeability geotechnical barrier using predominantly coarse grain materials by conventional compaction efforts is rarely attempted due to the difficulty of maintaining a uniform mix of well-graded sand and aggregate blends necessary to achieve low permeability. The regularly achievable permeability offered by this material blend when installed with specific proscribed techniques using conventional equipment can be 5×10.sup.−8 cm/sec or lower.

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.

The invention relates to a low-permeability geotechnical barrier material including a blend of approximately equal parts of: aggregate particles, sand-size particles and manufactured composite particles that include a hydratable sealant material composed of naturally-occurring clay minerals and/or polymer-enhanced clay minerals, such that the actual percentage of clay mineral component is less than 10% by weight in the blended material. In a particular embodiment, the construction of a low-permeability geotechnical barrier using predominantly coarse grain materials by conventional compaction efforts is rarely attempted due to the difficulty of maintaining a uniform mix of well-graded sand and aggregate blends necessary to achieve low permeability. The regularly achievable permeability offered by this material blend when installed with specific proscribed techniques using conventional equipment can be 510.sup.8 cm/sec or lower.