Butyl xanthate

Ethyl S-n-butyl xanthate. Use 32 g. of potassium ethyl xanthate, 37 g. (23 ml.) of n-butyl iodide (Section 111,40) and 50 ml. of absolute ethyl alcohol. Reflux on a water bath for 3 hours. Pour into 150 ml. of water, saturate with salt (in order to facilitate the separation of the upper layer), remove the upper xanthate layer, wash it once with 25 ml. of saturated salt solution, and dry with anhydrous calcium chloride or anhydrous calcium sulphate. Distil from a 50 ml. Claisen flask under reduced pressure. Collect the pale yellow ethyl S-n-butyl xanthate at 90-91°/4 mm. The yield is 34 g. 

Sulfur chemistry [29] has also been used to crosslink rubber/resin PSAs, although the use of elemental sulfur itself yields tapes that can stain substrates. Other patents exemplify the use of typical rubber vulcanizing chemistry such as Tetrone A , dipentamethylenethiuramtetrasulfide, and Tuads , tetramethylthiu-ram disulfide [30], or zinc butyl xanthate [31] for this purpose. Early art [32] also claimed electron beam curing of both natural rubber and other adhesives that were solvent coated on tape backings. Later references to electron beam curing... 

Flotation of pyrite using either ethyl xanthate or potassium butyl xanthate as collector. Glycol frother is also usually employed in this separation. 

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. 

The influence of pulp potential on the floatability of chalcopyrite is shown in Fig. 4.4 for an initial concentration of 2x 10 mol/L ethyl XMthate and butyl xanthate. The lower flotation potential is -O.IV for KBX and OV for KEX. The hydrophobic entity is usually assumed to be dixanthogen (Allison et al., 1972 Woods, 1991 Wang et al, 1992) by the reaction (1-3). The calculated potential in terms of reaction (1-3), are, however, 0.217 V and 0.177 V, respectively, for ethyl and butyl xanthate oxidation to dixanthogen for a concentration of 2 x lO" mol/L, which corresponds to the region of maximum recovery but not to the lower limiting potential for flotation, indicating that some other surface hydrophobicity to the mineral. Richardson and Walker (1985) considered that ethyl xanthate flotation of chalcopyrite may be induced by the reaction ... 

Only limited studies on the electrochemical behavior of sphalerite have been reported, perhaps due to its high electrical resistivity. The Relation between recovery of sphalerite and pulp potential is presented in Fig. 4.17 with an initial butyl xanthate concentration of 10 mol/L. It can be seen from Fig. 4.17 that flotation begins at 0 V, the upper limit potential is 0.31 V. 

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. 

Figure 4.29 Flotation recovery of arsenopyrite as a function of pulp potential (Arrow indicates the reversible potential of butyl xanthate/dixanthogen couple)...

Figure 4.30 Electrochemical phase diagram for the butyl xanthate/oxygen system and the observed lower and upper ( ) limiting flotation potential of galena and chalcopyrite at which flotation recovery is greater than 50% (EX 2 xlO mol/L)...

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...

The effect of DMPS on the flotation recovery of pyrrhotite and marmatite in the presence and absence of CUSO4 with butyl xanthate is shown in Fig. 5.16. It follows that the flotation of pyrrhotite and marmatite is greatly affected by DMPS addition. In the absence of cupric ion the recovery of pyrrhotite hardly exceeded 40%. At pH = 2, the recovery of marmatite is more than 90%, but the recovery sharply decreases to below 20% with pH increasing. These results show that pyrrhotite and marmatite can not be separated in the absence of cupric ion with DMPS as depressant and xanthate as a collector. In the presence of cupric ions, marmatite flotation improves under wide pH condition. The flotation of pyrrhotite is activated only aroimd pH = 2. The results demonstrate that flotation separation of copper-activated marmatite from pyrrhotite is possible in the presence of butyl xanthate and DMPS. 

Figure 5.20 FTIK spectra of maimatite in the absence of reagents and in the presence of CUSO4, butyl-xanthate, glycerin-xanthate (1 mannatite 2 marmatite+CuS04 + butyl-xanthate 3 marmatite + glycerin-xanthate + CUSO4 + butyl-xanthate)...

With butyl xanthate (1.0 x 10" mol/L) as a collector and 2,3-dihydroxyl propyl dithiocarbonic sodium (GX2) as a depressant, the flotation recovery of marmatite, arsenopyrite and pyrrhotite is given in Fig. 5.21 as a function of pH. 

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. 

The influence of pulp potential on the flotation of marmatite, arsenopyrite and pyrrhotite with 10 mol/L butyl xanthate as a collector in the presence of 150 mg/L 2,3-dihydroxyl propyl dithiocarbonic sodium (GX2) has been tested. Taking the flotation recovery to be 50% as a criterion, above which the mineral is considered to be floatable and otherwise not floatable, the upper and lower potential limits of the flotation of marmatite, arsenopyrite and pyrrhotite at different pH are presented in Fig. 5.25 and Table 5.1. It is evident that marmatite is floatable in some range of potential at various pH, whereas arsenopyrite and pyrrhotite are not floatable in the corresponding conditions. It suggests that the flotation separation of marmatite from arsenopyrite and pyrrhotite may be... 

Figure 5.25 The upper and lower potential limits of marmatite flotation with butyl xanthate as a collector in the presence of GX2...

Similarly, the influence of pulp potential on the flotation of marmatite, arsenopyrite and pyrrhotite with 10 mol/L butyl xanthate as a collector in the presence of 120mg/L (1-carbonic sodium-2-acetaic sodium) propanic sodium dithio carbonic sodium (TX4) has been tested. The results are given in Fig. 5.26 and Table 5.2. It can be seen from Fig. 5.26 that at pH=4.5 marmatite has wide floatable potential range from 0.3 V extended to above 0.7 V, at pH = 6.5 the floatable potential range is about 0.3-0.4 V, and at pH =9.2 marmatite is not floatable. Table 5.2 demonstrates that in these conditions, arsenopyrite and... 

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