Flotation recovery concentration

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.)...

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. 

The flotation results of three sulphide minerals in the presence of sodium sulphide are presented in Fig. 3.1 as recovery-concentration curves. In contrast to self-induced collectorless flotation, pyrite and arsenopyrite are strongly floatable while chalcopyrite and galena are weakly floatable in the presence of sodium sulphide. 

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...

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

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 5.3 Flotation recovery of galena and pyrite as a function of butyl xanthate concentration by using lime and sodium hydroxide at pH = 12...

Figure 5.15 Flotation recovery of chalcopyrite and galena as a function of concentration of hydrogen peroxide (Wang, 1992)...

At pH = 6, the flotation recovery of marmatite, arsenopyrite and pyrrhotite as a function of depressant dosage GX2 is given in Fig. 5.22. With the increase of GX2 dosage, the flotation recovery of these three minerals decreases. However, marmatite remains with reasonably high flotation recovery of above 70%, and arsenopyrite and pyrrhotite exhibit poor flotation with recovery of below 35% when the concentration of GX2 is above 120 mg/L. It indicates the possibility for flotation separation of marmatite from arsenopyrite and pyrrhotite by using 2,3-dihydroxyl propyl dithiocarbonic sodium as a depressant and butyl xanthate as a collector. 

Table 5.4 shows the formulae of four polycarboxylic xanthates. Figure 5.35 demonstrates the results of the polycarboxylic xanthates on the depression of arsenopyrite. It can be seen that the depression of the polycarboxylic xanthates on arsenopyrite increases with increase of depressant concentration and is in the order of TX4>TX3>TX2>TX1. At 100 mg/L, the flotation recovery can be below 20%.The more the carboxylic groups in the polycarboxylic xanthates, the stronger the depression on arsenopyrite. 

Figure 5.34 Flotation recovery of arsenopyrite as a function of polyhydroxyl xanthate concentration with butyl xanthate as a collector...

The i value and HLB value of polyhydroxyl and polycarboxylic xanfhates are calculated and shown in Table 5.5. It is obvious that the polyhydroxyl xanthate with more hydroxyl groups and polycarboxylic xanthate with more carboxylic groups have greater i or HLB value. Taking the i or HLB values as x-axis and the flotation recovery of arsenopyrite or pyrrhotite at depressant concentration... 

Figure 6.23 Flotation recovery of lime-depressed pyrite activated by organic acids vs. concentration of activators...

The comparison of flotation results using OPCF and traditional flowsheet is shown in Table 10.15. It can be seen that either PbS, ZnS flotation recovery or the grade of the concentration, is improved obviously in OPCF. The grade and recovery of lead concentration, respectively, increase from 73.77% to 79.19% and... 

Molybdenum is recovered primarily from its sulfide ore, molybdenite, M0S2. It also is produced, although to a much lesser extent, from the tungsten ore wulfenite, which yields lead molybdate, PbMo04. The first phase of the recovery process generally involves concentration of the ore, because ore coming from the mine is very lean and usually contains less than one percent molybdenum. Molybdenite at first is concentrated by flotation which concentrates the M0S2 over 90%. If wulfenite is used as a source material, concentration is usually done by hydrauhc methods. 

Figure 3- Flotation recovery R (in %) of fluorite as dependent on the concentration c (in mol/L) of Na-do-decylbenzenesulfonate.

The dependence of the values for surface concentrations of DBS in the presence > " in the absence ( dbS Cu(OH)2, on the initial DBS concentrations is depicted in Fig. 3. The figure actually shows the DBS separation in precipitate flotation in the presence of Cu(OH)2, as well as its recovery in the foam flotation. Surface concentrations of DBS obtained in the DAF system in the presence of Cu(0H)9 are about 10—30 times higher if compared to the DIS system. This is again the consequence of a smaller amount of air involved in the DAF system, which causes the total bubble surface to be lower. It is evident that the Tjjgg values in both systems are about 2—10 times lower from same time the recoveries of pure DBS are lower and... 

Fig. 2.20. Effect of chain length and concentration of amine acetates on the flotation recovery of quartz (Fuerstenau, 1964).

In flotation practice, less soluble frothers may also produce low frothing rate, finer bubbles and higher viscosity, and this can lead to higher flotation recovery. In contrast, soluble frothers exhibit fast frothing, coarser bubbles and brittle foam, and yield higher concentrate grade. 

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