EIS measurements of dithiocarbonate and trithiocarbonate interactions with pyrite and copper

Venter, J.A.; Vermaak, M.K.G.

doi:10.1016/j.mineng.2007.11.003

Cited by 16 publications

(14 citation statements)

References 5 publications

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“…(5)) on the pyrite surface at potentials more positive than the reversible potential of X À /X 2 couple. This is in good agreement with previous work conducted by Venter and Vermaak [22]. The reversible potential for xanthate oxidation to dixanthogen can be computed from the Nernst…”

Section: Characterization Of Pyrite Oxidation and Xanthate Adsorptionsupporting

confidence: 91%

“…2 is proposed for the electrochemical system to fit the experimental data by a nonlinear method using the ZView software. This equivalent circuit consists of a resistor R s (solution resistance) in series with a parallel circuit containing a capacitor C dl (capacitance of the electrical double layer) and a resistor R ct known as charge transfer (or polarization) resistance [22,23]. The simple equivalent circuit in Fig.…”

Section: Characterization Of Pyrite Oxidation and Xanthate Adsorptionmentioning

confidence: 99%

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Electrochemistry aspects of pyrite in the presence of potassium amyl xanthate and a lignosulfonate-based biopolymer depressant

Peng

Lauten³

2015

Electrochimica Acta

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Section: Characterization Of Pyrite Oxidation and Xanthate Adsorptionsupporting

confidence: 91%

Section: Characterization Of Pyrite Oxidation and Xanthate Adsorptionmentioning

confidence: 99%

Electrochemistry aspects of pyrite in the presence of potassium amyl xanthate and a lignosulfonate-based biopolymer depressant

Peng

Lauten³

2015

Electrochimica Acta

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“…This is in good agreement with a microflotation openUP (March 2008) study performed by Venter and Vermaak (2007a) indicating that decomposed TTC looses its effectiveness but still has a higher initial rate compared to xanthate. This is probably due to the hydrolysis of TTC, forming a mercaptan ([Du Plessis, 2003] and [Venter and Vermaak, 2007a]). The mercaptan/SIBX reference sample generally showed a distinct reduction in grade recovery and kinetics.…”

Section: Effect Of Diluted and Aged C12 Ttc On Auriferous Pyrite Flotsupporting

confidence: 89%

“…The xanthate adsorbs via a charge transfer process and as a result will only adsorb in the presence of an anodic current. More recent investigations ( [Venter and Vermaak, 2007a], [Venter and Vermaak, 2007b] and [Venter and Vermaak, 2007c]) indicated the adsorption of TTC onto the substrate in reducing conditions -it appears that TTC decomposes on the surface and the decompositional products render the surface hydrophobic. In case of potentials more positive than equilibrium potential of the TTC monomer-dimer couple some oxidation of the TTC occurs ([Du Plessis, 2003], [Venter and Vermaak, 2007a] and [Venter and Vermaak, 2007b]).…”

Section: Introductionmentioning

confidence: 99%

The flotation of auriferous pyrite with a mixture of collectors

Makanza¹,

Vermaak²,

Davidtz³

2008

International Journal of Mineral Processing

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Dithiocarbonates (xanthates) have been the most widely used collectors in sulphide mineral flotation. More recently, research has resulted in the use of trithiocarbonate (TTC) collectors. The present study focuses on the effect of mixtures of C 12 trithiocarbonate (C 12 TTC) and sodium iso-butyl xanthate (SIBX) in the flotation of auriferous pyrite and the associated gold and uranium from cyanidation tailings.Improved gold and uranium flotation responses were observed with collector mixtures than with SIBX alone. Sulphur recoveries were not affected. Mineralogical analysis of flotation concentrates showed that gold and uranium were also hosted by kerogen. It was therefore proposed that the improved recoveries could have been mostly due to higher kerogen recovery rather than synergism in pyrite flotation. This mechanism opens possibilities into maximising uranium recoveries in auriferous flotation circuits where low recoveries are common.

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“…At −0.2 V, the C sl value in xanthate containing solution is lower than that in background solution. Significant decrease of C sl (almost one order of magnitude) as a result of xanthate addition is observed at 0 V and 0.2 V. The adsorption of xanthate leads to a decrease of capacitance due to its low dielectric constant 30, 31. Thus the decrease of C sl value in the present study indicates the formation of xanthate layer on pyrite surface.…”

Section: Resultssupporting

confidence: 47%

The Poisoning of Pyrite Surface upon Xanthate Adsorption by Cyanide in Mildly Acidic Media

Guo

2015

Electroanalysis

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[a] 1Introduction Thea dsorption of organic species ontom inerala tt he solid-liquid interface is of significance for the establishmento fh ydrophobics urface,r enderingm inerals flotation possible.I ti sn ow well established thatt he interaction of typicalc ollector xanthate withp yrite, the most abundant sulfide minerals is electrochemicali nn ature [ 1].T he pyrite-xanthatei nteraction is affected by manyf actors sucha spH, redox potential,a nd differents olution species, in addition to the history of the mineral. It was reported [2-4] thatt he maximum flotationr ecoveryo fp yritei so bserveda tm ildly acidicp H( 3.5-5.5),e specially withl ow xanthate concentration. Thed epression at lower pH has been attributed to the decomposition of xanthatei ons [ 4]. Thec hemisorption of xanthatep resumably involves the oxidation of xanthatet od ixanthogeno np yrite [4][5][6][7][8]. Spectroscopics tudies [ 8] showt hatt he amount of adsorbed xanthater eaches am aximuma tp H5 after treatmentw ith1 0 À4 xanthate solution andd ecreases steadily withf urtheri ncreasingp H. Theg reater extent of hydrophilic ferric hydroxidecoverage on pyritewith the increasingpHisunfavorable for the adsorptionofxanthate [4,7]. Thepoorfloatabilityinneutral media hasalsobeenattributedt ot he formation of hydrophilicf erric dihydroxyx anthate,F e(OH) 2 EX, over apHrange from5to 9 [2,3].It was also revealed that cyanide inhibited all surface electrochemical activities, rendering pyrite surface hydrophilic [9][10][11][12][13][14].C yanide speciation largelyd epends on pH of the solution. Thec yanide anion in aqueous solution forms hydrocyanic acid (HCN)a ccording to the dissociation reaction in Equation (1) [15].Thel ogarithmic exponent of the dissociation constant pKa of HCN at 25 8Cis9 .21 [16].ApH value higher than 9.21 increases CN À concentration while ap Hvalue lower than 9.21 promotes the presence of aqueous HCN in the solution.C yanide consistently exists as HCN whenp Hi s lower than 7 [ 16].T hough numerous studies of this system were carried out, the depression mechanism of cyanide has been controversial and was postulated to be associated with the formation of iron-cyanide compounds on pyrite surface [17,18] or the inhibitiono fx anthate oxidation at reducingp otential in the presenceo fc yanide [13,19].F urthermore,t hose studies involving cyanidepyrite interaction were conducted at neutralt oa lkaline pH. Thex anthate chemisorption in the presenceo fH CN in mildly acidic media is unknown, whichi s, however, of great importance whent he maximum recovery of pyrite is desired in flotation, particularly for auriferous pyritic ore.Due to the maximum xanthate chemisorptiono np yrite can be achieved at pH 5[ 8],t he impact of HCN on pyrite-xanthate interaction was investigated at pH 5b y means of electrochemical measurements. 2Experimental MethodsAh and-picked naturalm assive cubic pyrite specimen originated fromS pain was used as workinge lectrode.X -ray fluorescence (XRF) analysis shows that the pyrite specimen had as ulfurc ontento f6 ...

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EIS measurements of dithiocarbonate and trithiocarbonate interactions with pyrite and copper

Cited by 16 publications

References 5 publications

Electrochemistry aspects of pyrite in the presence of potassium amyl xanthate and a lignosulfonate-based biopolymer depressant

Electrochemistry aspects of pyrite in the presence of potassium amyl xanthate and a lignosulfonate-based biopolymer depressant

The flotation of auriferous pyrite with a mixture of collectors

The Poisoning of Pyrite Surface upon Xanthate Adsorption by Cyanide in Mildly Acidic Media

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