Abstract: The invention relates to the use of at least one mixed mineral organoclay rheology additive, which comprises or consists of a quaternary alkyl-ammonium salt treated mineral clay mixture prepared by forming an aqueous hormite clay slurry (a), forming an aqueous smectite clay slurry (b), combining the aqueous hormite clay slurry (a) with the aqueous smectite clay slurry (b) to form a combined clay slurry (c), treating the combined clay slurry (c) with one or more quaternary alkyl-ammonium salts, separating the thus produced quaternary alkyl-ammonium salt treated mineral clay mixture from the aqueous medium, in which the aqueous hormite clay slurry (a) being formed by (i.1) dispersing a fraction of one or more hormite clays selected from the group of sepiolites and palygorskites in an aqueous medium to form a dispersion, and the aqueous smectite clay slurry (b) being formed by (ii.

Abstract: The invention relates to the use of at least one mixed mineral organoclay rheology additive, which comprises or consists of a quaternary alkyl-ammonium salt treated mineral clay mixture prepared by forming an aqueous hormite clay slurry (a), forming an aqueous smectite clay slurry (b), combining the aqueous hormite clay slurry (a) with the aqueous smectite clay slurry (b) to form a combined clay slurry (c), treating the combined clay slurry (c) with one or more quaternary alkyl-ammonium salts, in which the aqueous hormite clay slurry (a) being formed by dispersing a fraction of one or more hormite clays selected from the group of sepiolites and palygorskites in an aqueous medium to form a dispersion, and whereby the hormite clay fraction employed contains less than 3.0% by weight of Al2O3, less than 1.0% by weight of Fe2O3, and less than 3.