Stable aqueous composition of neutral collectors and their use in mineral beneficiation processes

A process for manufacturing a stable aqueous emulsion comprising the steps of mixing a thionocarbamate (component a), selected from the group consisting of dialkyl thionocarbamates, alkyl alkoxycarbonyl thionocarbamates and alkyl allyl thionocarbamates, with a surface active agent (component b) of the general formula

• wherein
• R1 is a saturated or unsaturated, branched or linear C3 to C30 aliphatic or aromatic hydrocarbon group,
• R2 and R3 are independently from each other hydrogen or a C1 to C4 alkyl group,
• R4 is hydrogen or —CH2—COOX, where X is hydrogen or sodium salt or potassium salt or ammonium salt, and
• n and m are independently from each other 0 to 50, and a mixture of at least one alcohol and at least one ether and/or ester (component c) and optionally a water soluble, anionic collector (component d) to yield a homogeneous mixture, and adding the homogenous mixture to water under high mechanical shear generated by a rotor-stator homogenizer to form the stable aqueous emulsion, wherein the at least one ether corresponds to the formula
• R5—O—R6
• wherein
• R5 is a linear or branched alkyl or alkenyl group having 2 to 30 carbon atoms and
• R6 is a linear or branched alkyl or alkenyl group having 1 to 30 carbon atoms.

A process for beneficiation of a metal sulfide mineral or ore, the process comprising the steps of bringing the mineral or ore in contact with an aqueous collector composition comprising a stable aqueous emulsion, wherein the stable aqueous emulsion comprises

• a) 1-50 wt.-% of at least one water insoluble thionocarbamate collector selected from the group consisting of dialkyl thionocarbamates, alkyl alkoxycarbonyl thionocarbamates and alkyl allyl thionocarbamates,
• b) 1 -50 wt.-% of one or a mixture of surface active agents of the general formula
• wherein
• R1 is a saturated or unsaturated, branched or linear C3 to C30 aliphatic or aromatic hydrocarbon group,
• R2 and R3 are independently from each other hydrogen or a C1 to C4 alkyl group,
• R4 is hydrogen or —CH2—COOX, where X is hydrogen or sodium salt or potassium salt or ammonium salt, and
• n and m are independently from each other 0 to 50,
• c) 0.1-20 wt.-% of a mixture of at least one alcohol and at least one ether and/or ester, and
• e) 1-90 wt.-% of water, to form a mineral pulp,
• and subsequently frothing the mineral pulp, wherein the at least one ether corresponds to the formula
• R5—O—R6
• wherein
• R5 is a linear or branched alkyl or alkenyl group having 2 to 30 carbon atoms and
• R6 is a linear or branched alkyl or alkenyl group having 1 to 30 carbon atoms.