Study On Activation Behavior Of α-nitroso-β-naphthol In Flotation Of Hemimorphite

As the primary source of zinc, natural sulfide ores are steadily getting depleted. Forfuture demand, there is an obvious recognition that the recovery and utilize of zinc fromoxidized zinc ore. Reseachers both at home and overseas have paid extreme attention to theflotation reagents and technology in the flotation of oxidized zinc ore. Until now, it is hard toachieve ideal flotation index for its complex structure, varied surface characteristics andcomponents.Oxidized zinc ore in Shizhu county of Chongqing mainly exists as hemimorphite, andalso contains a few smithsonite and willemite. The main parts of matrix are quartz, dolomiteand ferric of4%content. The intergrowth relationship between oxidized zinc ore and matrixis closed and complicated. When the mineral is broken up and milled, it is easy to cause largemount of slime resulting in processing diffucultly. So it is of certain representative to developand utilize.In this research, α-nitroso-β-naphthol as activtor, octadecylamine and benzohydroxanicacid as collectors were adopted in oxidized zinc ore flotation for satisfied results. The effect ofpH, the dosage of collector, activator and four kinds of dispersants on the flotation werediscussed basing on the single factor experiment. When octadecylamine was used as thecollector, the grade of zinc concentrate was up to38.26%with recovery of87.90%in thepresence of pH:9.5,2×10^-5mol/L α-nitroso-β-naphthol,1200g/t octadecylamine and1200g/tcalcium lignosulphonate. As mentioned to benzohydroxanic acid, the optimal conditions wereas follows: pH:9.0, dosage of sodium hexametaphosphate, α-nitroso-β-naphthol andbenzohydroxanic acid were1000g/t,2×10^-5mol/L and800g/t, repectively. The grade of zincconcentrate was up to40.36%with recovery of61.20%. Compared with other systems, theaddition of activtor was low and the dosage of reagents decreased obviously. This technologyprocess was much more effective with low consumption, furthermore, increased theselectivity. The dispersion performance of the three kinds of dispersant （sodiumhexametaphosphate, sodium silicate and calcium lignosulphonate） was also studied. Theresults demonstrated that sodium hexametaphosphate and calcium lignosulphonate were thesuitable dispersants.The measurement of adsorption amount of the reagents, the infrared spectrum and thegroup electronegrativity calculation have all been used in the research in order to study themechanism of the reaction between the flotation reagents and the surface of mineral. Theresults of adsorption measurement and the infrared spectrum showed thatα-nitroso-β-naphthol have chemical adsorption on oxidized zinc ore, and demonstrated thatthere was a five-ring chelate formed by the nitrogen and oxygen atoms in the molecular of the α-nitroso-β-naphthol with Zn2+on the mineral surface, which made the mineral surfacehydrophobic to some extent and consequently promoted adsorption of collectors on themineral surface. The data of the group electronegrativity calculation showed that the chanceof forming N, O type five-ring surface chelate was much more than the chance of forming theother chelate.