The Selection of Reagents for Ionic Flotation of Non-Ferrous Metals in the Series of N-Acyl-N'-Mezylhydrazines

A series of new ligands — N-acyl-N'-mesylhydrazines (MSH) — of the general formula RC(O)NHNHSO2CH3 has been obtained and considered as reagents for ionic flotation (IF) of non-ferrous metals (M(II). Reagents with a radical length of C6H13 and above form hardly soluble complexes with M(II) so it is possible to implement a kind of the ionic flotation techniques — “precipitate flotation”. The ranges of pH values of the most complete precipitation of cations from solutions have been determined. Precipitates of the metal complexes were isolated; their composition was confirmed by IR spectroscopy and elemental anal-ysis. The conditional values of the solubility product (SP) of the complexes [M(HL)2] were calculated. The dependence –lg SP = 11.8 + 0.61N is fulfilled for the MSH series and Cu(II) ions. The surface-active proper-ties of compounds with R > C6H13 were established. The reagents with optimal radical length for ionic flota-tion were selected. The ionic flotation of non-ferrous metals with N-nonanoyl-N'-mesylhydrazine was carried out. The up to 95–99 % recovery of metal ions, separation of copper and associated metal ions in diapason of pH 5–6.5 was shown to be possible.