Flotation recovery

Fig. XIII-9. The dependence of the flotation properties of goethite on surface charge. Upper curves are potential as a function of pH at different concentrations of sodium chloride lower curves are the flotation recovery in 10 M solutions of dodecylammo-nium chloride, sodium dodecyl sulfate, or sodium dodecyl sulfonate. (From Ref. 99.)...

Fig. 1. Effect of particle size on the flotation recovery of a sulfide mineral. Mineral chalcocite [2112-20-9J, CU2S reagent potassium ethyl xanthate,...

The 2eta potential and contact angle as well as flotation recovery correlate well in some flotation systems as shown in Figure 9 (20). 

Fig. 9. Correlation of contact angle, flotation recovery, surface coverage by collector, and 2eta potential. Solid, quart2, collector reagent, 4 x 10 Af dodecylammonium acetate. = recovery, % A = zeta potential, mV Q — contact angle, degrees and = surface coverage, % of one monolayer. Ref.

Flotation process kinetics determine the residence time, the average time a given particle stays in the flotation pulp from the instant it enters the ceU until it exits. One way to study flotation kinetics is to record flotation recoveries as a function of time under a given set of conditions such as pulp pH, coUector concentration, particle size, etc. The data allow the derivation of an expression that describes the rate of the process. 

Sulfide collectors ia geaeral show Htfle affinity for nonsulfide minerals, thus separation of one sulfide from another becomes the main issue. The nonsulfide collectors are in general less selective and this is accentuated by the large similarities in surface properties between the various nonsulfide minerals (42). Some examples of sulfide flotation are copper sulfides flotation from siUceous gangue sequential flotation of sulfides of copper, lead, and zinc from complex and massive sulfide ores and flotation recovery of extremely small (a few ppm) amounts of precious metals. Examples of nonsulfide flotation include separation of sylvite, KCl, from haUte, NaCl, which are two soluble minerals having similar properties selective flocculation—flotation separation of iron oxides from siUca separation of feldspar from siUca, siUcates, and oxides phosphate rock separation from siUca and carbonates and coal flotation. 

Most of the current commercial operations that treat PGM from sulphide-dominated deposits are located in South Africa (Morensky Reef), Stillwater mines (Montana, USA) and Lac des Hies (Ontario, Canada). From a processing point of view, most of these ore types contain hydrophobic gangue minerals, including talc, which has a negative effect on PGM recoveries. Other major factor that affects flotation recovery of PGM is the presence of a variety of sulphide minerals, including pyrrhotite, pentlandite, chalcopyrite, violarite and pyrite, where... 

Sodium alkyl sulphonate is also a collector for tantalite and columbite at a pH below 3.0 (Figure 23.2). At a pH above 3.0, flotation recovery of tantalite and columbite decreased rapidly. This collector was not selective towards gangue minerals, such as tourmaline and garnet. 

Figures 2.6, 2.7 and 2.8 provided the evidence that there exists the critical upper and lower limit of pulp potential for collectorless flotation at certain pH. Figure 2.9 further demonstrated the flotation recovery of jamesonite as a function of potential at different pH. It is obvious that jamesonite has very good collectorless floatability in different potential range, which much depended on different pH. The...

The collectorless flotation recovery of marmatite, pyrrhotite and jamesonite and the amount of extracted sulphur as a function of pH are shown in Figs. 2.28, 2.29 and 2.30. Figure 2.28 shows that the trend of recovery of marmatite is consistent with change of the amount of extracted sulphiu. They all decrease with the increase of pH. In acidic pH media, both collectorless flotation recovery of marmatite and the amount of extracted sulphur from its surface are the maximum. 

Figure 2.28 Collectorless flotation recovery of marmatite and the amount of extracted sulphur as a fimction of pH...

Figure 3.1 Flotation recovery of sulphide minerals as a function of Na2S concentration at pH = 11 (Wang and Hu, 1992 Wang and Long, 1991)...

Figure 3.2 Sodium sulphide-induced collectorless flotation recovery of pyrrhotite as a function of Na2S concentration...

Flotation recovery of jamesonite as a function of Na2S concentration is shown in Fig. 3.3. It follows that the recovery of jamesonite is decreased by the addition of low dosage of Na2S at various pH. In contrast to self-induced collectorless flotation, the collectorless flotation of jamesonite is depressed in the presence of sodium sulphide. In alkaline pH range, the self-induced collectorless flotation of jamesonite is sharply depressed by the addition of Na2S. In acidic pH range, the... 

Figure 3.5 Sulphur-induced collectorless flotation recovery of pynhotites, jamesonite and marmatite as a function of NaaS concentration at pH = 8.8...

Figure 3.9 Anodic current and contact angle as a function of potential for sulphidized pyrite compared with flotation recovery (Heyes and Trahar, 1984)...

Figure 4.2 Flotation recovery of chalcocite with ethyl xanthate as a function of potential curve 1-from Basiollio et al. (1985), solution pH = 11 (la),8(lb),5(lc) curve 2-from Heyes and Trahar (1979), solution pH= ll(2a) and 8(2b) curve 3-from Richardson et al. (1984), at pH = 9.2...

Figure 4.4 Flotation recovery of chalcopyrite as a function of pulp potential...

Figure 4.12 Flotation recovery of jamesonite as a function of pulp potential in the presence of collector (collector concentration 10" mol/L, pH = 8.8)...

Figure 4.20 Flotation recovery of marmatite as a function of pulp potential with ethyl xanthate as a collector at different pH (KEX 10" mol/L)...

The relationship between pyrrhotite flotation recovery and pulp potential is presented in Fig. 4.26. It can be shown that the flotation of pyrrhotite has different... 

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