Water swellable clay composition and method to maintain stability in salt contaminated water
US4634538A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1985 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Jun 28, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/206
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Disclosed is a composition including a water swellable clay, and particularly a montmorillonite clay, such as bentonite; xanthan gum; and one or more additional water-soluble gums, for example, guar dextran, acacia or locust bean. The xanthan gum together with one or more additional water-soluble gums prevents montmorillonite clay composition from substantial coagulation or flocculation upon contact with salt contaminated water even in high concentrations of, for example, 15-40% by weight salt. It has been found that xanthan gum in an amount of 0.1-20% based on the weight of the water-swellable clay, i.e. bentonite, in the composition together with one other water soluble gum, for example guar gum, dextran gum, acacia gum and/or locust bean gum in an amount of 1.0-10% based on the weight of bentonite in the composition will provide a clay composition capable of excellent stability without component separation in salt contaminated water. The composition is particularly useful as an additive to compositions used as stable drilling fluids in rotary drilling, and as lagoon and landfill sealants.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.