Patent ID: 8496115

Claim:
A method for separating off insoluble components from sylvinite comprising the steps of suspending the sylvinite in saturated salt lye, adding a flocculant to the suspension, and subsequently adding a frother to the resultant suspension composition, wherein the frother comprises at least one polypropylene glycol and at least one ether or ester, wherein a) the at least one ether corresponds to formula 1 R—O—R′ (1) wherein R is linear or branched alkyl or alkenyl groups having 2 to 30 carbon atoms and R′ is linear or branched alkyl or alkenyl groups having 1 to 30 carbon atoms, b) the at least one ester is derived from monobasic or polybasic carboxylic acids having 2 to 30 carbon atoms and monohydric or polyhydric alcohols having 1 to 30 carbon atoms, or c) the at least one ether or ester are cyclic, wherein the ring size is from 6 to 30 carbon atoms.