Iron Sulphide Minerals

The influence of potential on the floatability of pyrite with butyl xanthate as a collector has been determined and the result is given in Fig. 4.23. It follows that flotation begins at 0.1 V for an initial KBX concentration of 10 mol/L. The flotation potential ranges from 0.10 V to +0.31 V. 

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 

The anodic scan section of cyclic voltammetry for pyrrhotite electrode, respectively, in pH=7, 8.8, 11, 12.1, 12.7 buffer solution with dithiocarbamate are presented in Fig. 4.28. The cyclic voltammograms curve at pH = 8.8 is also presented in Fig. 4.28. It can be seen that the anodic ciurent peak emerges at about O.IV. As pH increases, the peak moves to the left. This peak may correspond to the formation of disulphide. When the concentration of dithiocarbamate is 10 mol/L, the oxidation of dithiocarbamate forming disulphide is h = 0.22 V, which agrees with the results in Fig. 4.26. When the hydrophobic entity disulphide was formed, the flotation of pyrrhotite could be possible. 

It can be also seen from Fig. 4.28 that the place of anodic peaks moves towards the left with the increase of pH. When pH= 12.7, the anodic peak disappears, and the anodic current increases rapidly. It indicates that only the oxidation of pyrrhotite takes place on the surface of pyrrhotite. In addition, no disulphide was formed at pH = 12.7. So the flotation of pyrrhotite could not be carried out. 

Arsenopyrite exhibits similar xanthate induced floatability to pyrite. The result obtained by Feng (1989) is presented in Fig. 4.29. It follows that flotation occurs at potential where dixanthogen is formed, confirming the mechanism of formation of dixanthogen from Allison et al. (1972). 

---

Abstract In the beginning, the mixed potential model, which is generally used to explain the adsorption of collectors on the sulphide minerals, is illustrated. And the collector flotation of several kinds of minerals such as copper sulphide minerals, lead sulphide minerals, zinc sulphide minerals and iron sulphide minerals is discussed in the aspect of pulp potential and the nature of hydrophobic entity is concluded from the dependence of flotation on pulp potential. In the following section, the electrochemical phase diagrams for butyl xanthate/water system and chalcocite/oxygen/xanthate system are all demonstrated from which some useful information about the hydrophobic species are obtained. And some instrumental methods including UV analysis, FTIR analysis and XPS analysis can also be used to investigated sulphide mineral-thio-collector sytem. And some examples about that are listed in the last part of this chapter. 

Figure 5.31 Zeta potential of zinc-iron sulphide minerals as a function of pH...

Electrochemical Mechanism of Copper Activating Zinc-Iron Sulphide Minerals... 

Table 6.1 Eh-pH area of flotation of Zinc-Iron sulphide minerals in the presence of 10 mol/L Cu with 10 mol/L butyl xanthate as a collector...

Activation of Copper Ion on Flotation of Zinc-Iron Sulphide Minerals in the Presence of Depressants... 

The influence of copper ion on the flotation of zinc-iron sulphide minerals in the presence of depressant with butyl xanthate l.Ox 10 mol/L as a collector is presented in Fig. 6.11 to Fig. 6.14. It can be seen from Fig. 6.11 and Fig. 6.12 that in the presence of 120 mg/L 2-hydroxyl ethyl dithio carbonic sodium (GXl) and 2,3 dihydroxyl propyl dithio carbonic sodium (GX2), marmatite is activated by copper ion and exhibits very good flotation with a recovery above 90% in the pH range of 4-8. The flotation of arsenopyrite and pyrrhotite is poor with a... 

Figure 6.11 Flotation response of zinc-iron sulphide minerals as a function of pH in the presence of 120 mg/L GXl and 1.0 x 10 mol/L CUSO4 with butyl xanthate as a collector...

Figure 6.13 and Fig. 6.14 demonstrate the flotation results of zinc-iron sulphide minerals with l.Ox lO mel/L butyl xanthate as a collector in the presence of (1-carbonic sodium-2-hydroxyl) sodium propronate dithio carbonic sodium (TX3) or (1-carbonic sodium-2-sodium acetate) sodium propronate dithio carbonic... 

Besides, the polarization resistance of sphalerite electrode is the highest among lead-zinc-iron sulphide minerals, illustrating its poor conductivity of ZnS. 

Lead-Zinc-Iron-Sulphide Minerals and Ores... 

The CLEAR process is designed to completely leach the copper values from a copper concentrate consisting of any combination of copper sulphide or copper iron sulphide mineralization. The most abundant copper mineral is chalcopyrite whose composition is... 

Semiconductors are considered to be catalytic particles that contributed to the development of primitive metabolism. According to Wahtershauser life could have developed on the surface of iron sulphide minerals (eg mackinawite or pyrrhotite [FeS] or pyrite [FeS2]) [8], The chemoautotrophy theory is based on the reaction between iron sulphide and hydrogen sulphide, which acts as a reducing agent, whereas iron sulphide provides adsorption sites for substrates and acts as a catalyst (equation 10.1) ... 

Vaughan D. J. and Lennie A. R. (1991) The iron sulphide minerals their chemistry and role in nature. Sci. Progr. Edinburgh 75, 371-388. 

For stable sulphur isotopes, the standard is an iron sulphide mineral (troilite) from the Canyon Diablo meteorite. It is known as CDT (Canyon Diablo troilite) and equation 1 becomes ... 

A special case of corrosive action was reported by Oberholster [71]. The components of Carbotriferous shale aggregate were the iron sulphide minerals, such as pyrrhotite, pyrite, chalcopyrite. The first was oxidized pyrrhotite ... 

---