Patent ID: 7022838

Claim:
A method of recovering xanthan gum from an aqueous fluid, comprising: providing an aqueous fluid comprising water and at least about 1 wt % and 10 wt % xanthan gum, wherein the xanthan gum is substantially dissolved in the aqueous fluid, mixing the aqueous fluid and an organic non-solvent stream comprising water and an organic non-solvent of xanthan gum, thereby producing a first mixture, wherein the first mixture comprises a sub-precipitant concentration of the organic non-solvent; concentrating the first mixture, thereby increasing the xanthan gum concentration, wherein after concentrating the organic non-solvent concentration in the first mixture is below the minimum concentration at which the xanthan gum begins to precipitate; heating the first mixture to a temperature of between about 90° C. and about 125° C. for at least about five minutes; and mixing an additional amount of organic non-solvent with the first mixture, thereby producing a second mixture, wherein the second mixture comprises (A) a liquid component comprising organic non-solvent and water, wherein the organic non-solvent concentration in the second mixture is sufficient to precipitate a majority of the xanthan gum present in the second mixture, and (B) precipitated xanthan gum.