Societe Nationale Elf Aquitaine (Production)

Guy Levesque

Pierre Tozzolino

Jean-Louis Detienne

The froth flotation of a metal sulfide mineral is carried out using a thioamide as the collector in which the thioamide is of the formula ##STR1## R designating C.sub.5 to C.sub.17 alkyls, R' being H or (CH.sub.2).sub.n OR' and n an integer of 1 to 6, while Z is --OR' or ##STR2## where R' means H, CH.sub.3 or C.sub.2 H.sub.5.

Thioamides, their preparation and uses

Mono- and dithioic esters, the alcohol residue of which carries a group including one or more oxygen atoms, are prepared by the action of an oxygen-containing organic compound, carrying an active atom, upon a mixed magnesium salt of a mono- or dithioic acid, ##STR1## where Y is O or S, R is a hydrocarbon group and X is a halogen. The product obtained is treated with an aqueous acid. The new products so synthesized are of the type ##STR2## notably those where R' is a chain, --(CH.sub.2).sub.n --, with n=1 to 12, Z being --OH or --COOH and are used as a collector in the flotation of minerals.

Mono- and dithioic esters, their preparation and uses

Process for the preparation of an organic dithio-acid by reaction of the corresponding dithio-ester and an alkali metal or alkaline earth metal hydrosulphide in a solvent in the presence of an excess of H.sub.2 S and treatment with a mineral acid. The dithioic acids so obtained can be utilized as collectors for the flotation of minerals.

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Ballon, France

Guy Levesque