Chalcopyrite Flotation Research Articles

Adsorption and desorption of butyl xanthate on chalcopyrite

Reagent removal is an indispensable step to further separation of the copper sulfide ore flotation mixed concentrate, and xanthate is one of the most commercially used collectors for chalcopyrite flotation. In this work, the adsorption/desorption quantity of butyl xanthate was measured by the spectrophotometric method. Three adsorption models of Langmuir, Freundlich, and Temkin were used to fit the xanthate adsorption quantity dates. The results show that the adsorptions of sodium butyl xanthate on chalcopyrite match the Langmuir model best in the experimental conditions. Sodium sulfide dosage, pH value, ultrasonic wave, and temperature all show effects on butyl xanthate desorption. Butyl xanthate desorption can promote by increasing the dosage of sodium sulfide, ultrasonic wave intensity, temperature, and acidity or alkalinity of pulp. The order of the effectiveness of four conditions is sodium sulfide dosage, temperature, pH, and ultrasonic.

The effect of sodium hydrosulfide on molybdenite flotation in seawater and diluted seawater

Seawater is used in copper-molybdenum flotation plants when fresh water resources are limited. To minimize the negative effect of process seawater on molybdenite flotation, diluting process seawater with fresh water is a common practice. This study was designed to identify whether the dilution of process seawater in copper-molybdenum flotation plants benefits molybdenite flotation where NaHS is added to depress chalcopyrite. Seawater was prepared based on the concentrations of salts in the process seawater used in a copper-molybdenum flotation plant, and diluted with different proportions of de-ionized water. The concentrations of NaHS chosen to test in molybdenite flotation were determined by conducting chalcopyrite flotation to depress chalcopyrite. It was found that the concentration of NaHS which maximumly depressed chalcopyrite also depressed molybdenite to some extent in both seawater and diluted seawater. Water chemical equilibrium calculation, Cryo-XPS analysis and SEM measurement indicated that the depression mechanisms of NaHS on molybdenite were different in seawater and diluted seawater. Significant dilution of seawater weakened the buffer effect of seawater on pH and raised the pH in flotation significantly after the addition of NaHS so that Mg(OH)2 and CaCO3 precipitates formed to depress molybdenite. Insignificant dilution of seawater had little effect on flotation pH after the addition of NaHS, but the adsorption of HS− and the formation of SO42− on micro-edges of basal plane surfaces of molybdenite at a high NaHS concentration decreased the hydrophobicity of the basal plane surfaces, leading to reduced molybdenite flotation recovery.

Amphiphilic cellulose and surfactant mixtures as green frothers in mineral flotation. 2. Flotation of chalcopyrite and Cu-containing tailings

Froth flotation represents one the most important technologies for the development of the modern era, as it has enabled a steady and affordable flow of mineral raw materials. Recent studies show an increasing demand for more environmentally friendly processes, resulting in stricter regulations and the need to gain social license to operate by mining operations. As the demand of raw materials keeps growing, and ore grades decline, there is an urgent need to improve the efficiency of flotation as well as reducing the environmental impact of enrichment processes.The work hereby presented explores a novel type of frother chemistry, where commercial frothers are partially substituted with a biodegradable molecule produced from sustainable sources (namely, hydroxypropyl methyl cellulose) to form polymer-surfactant (PS) mixtures. In the second part of this series, the unique froth stabilization of this PS-mixture is tested in a bench-scale flotation study on chalcopyrite model ore. The use of PS-mixtures results in a robust system capable of maintaining separation efficiencies (SE) at ca. 90 % even under conditions of low pH (i.e., 5.5) and low collector concentration (i.e., 5 g/ton). In comparison, benchmark commercial frothers had a significant decrease in SE under these conditions (ca. 78 %). The advantageous performance of the PS-mixture frother is further tested in a short case study made with Cu-bearing sulfidic tailings. The outcome of this study demonstrates for the first time various advantages of the PS-mixtures in froth flotation, including: i) the generation of a stable, yet selective froth phase with sustainable reagents; ii) a robust flotation performance, able to withstand changes in pH and collector concentration, and iii) the ability to selectively float minerals with low hydrophobicity, such as those found in tailings deposits.

Flotation separation of chalcopyrite from talc using a new depressant carrageenan

As a typical gangue mineral in many sulfide deposits, naturally hydrophobic talc needs to be depressed by adding depressants to achieve a good flotation separation. Conventional talc depressants lack selectivity, resulting in the depression of both talc and sulfide minerals. In this study, carrageenan was applied as a selective depressant for talc. The mechanism of carrageenan in the flotation separation of chalcopyrite from talc when using collector sodium butyl xanthate (SBX) was investigated. Micro-flotation results showed that carrageenan can efficiently and selectively depress talc and barely influenced the flotation of chalcopyrite. The artificial mixed minerals flotation results further confirmed that carrageenan was a selective depressant for talc. A concentrate with Cu grade of 32.42 % was obtained at 91.86 % recovery from their artificial mixtures of minerals. The flotation results indicated that carrageenan exhibited stronger depressing ability than the conventional talc depressants of CMC and guar gum, suggesting it could become a promising potential depressant in the selective flotation separation of chalcopyrite from talc. Adsorption mechanism of carrageenan on the surface of talc was investigated using zeta potential measurements, adsorption measurements, FTIR measurements, XPS measurements and Langmuir adsorption model. The zeta potential measurements and adsorption measurements indicated that carrageenan selectively adsorbed on talc surface and therefore changed the zeta potentials. The FTIR results and XPS tests illustrated that the adsorption of carrageenan on talc occurred through physical interactions rather than chemical complexation. Langmuir adsorption modeling confirmed the major role of hydrophobic interaction.

Effect of Grinding Media on Grinding-Flotation Behavior of Chalcopyrite and Pyrite

Grinding media have significant influence on the flotation of chalcopyrite and pyrite. This effect is mainly related to the change in the surface properties of chalcopyrite and pyrite. This paper investigates the influence of steel ball and nano-ceramic ball grinding on the floatability of chalcopyrite and pyrite. Flotation results, as well scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet spectrophotometer, and zeta potential measurement results indicate that nano-ceramic ball grinding is beneficial to the flotation of chalcopyrite. Flotation results also indicate that chalcopyrite has better floatability after nano-ceramic ball grinding compared with steel ball grinding. Results of adsorption experiments show that nano-ceramic media grinding contributes to the adsorption of chalcopyrite and isobutyl xanthate. XPS and SEM techniques demonstrated that steel ball grinding easily produces oxidation species at the surface of chalcopyrite, thereby reducing its floatability. Results from this study also confirmed that steel ball grinding is beneficial to the flotation of pyrite. Therefore, nano-ceramic media grinding produces better selective flotation in chalcopyrite than steel media grinding.

The critical degree of bornite surface oxidation in flotation

The net effects of the alterations of surface chemistry of copper sulphide minerals on their flotation upon oxidation are documented to be either beneficial or detrimental, depending on the extent of mineral surface oxidation. However, there were limited reports in literature that established a quantitative relationship between surface oxidation and flotation, which renders the exercise of flotation optimisation for oxidised ores difficult, until our recent work on chalcopyrite and chalcocite. The degree of surface oxidation was quantified as the ratio of hydrophilic to hydrophobic oxidation species, which were characterised by X-ray Photoelectron Spectroscopy (XPS), and correlated with flotation recovery. Herein we tailored the method, which was previously developed on chalcopyrite and chalcocite, to establish a quantitative relationship between the degree of surface oxidation and flotation of bornite, one of the most valuable sources of commercial copper. The critical oxidation degree, beyond which bornite flotation becomes impossible, was determined to be 5.66. This is half that of chalcopyrite flotation and slightly higher than the upper limit of the range within which the critical degree of surface oxidation in chalcocite flotation was estimated to lie. Such knowledge betters the holistic understanding of the quantitative relationship between surface oxidation and copper sulphide flotation and will aid in providing insights on how to better handle ores of various oxidation degrees and susceptibilities. A comprehensive comparative case between bornite, chalcopyrite and chalcocite is presented in the paper.

A Study of Temperature Effect on the Xanthate’s Performance during Chalcopyrite Flotation

A multi-scale investigation was conducted to study the surface properties of xanthate-absorbed chalcopyrite at elevated temperature to understand the temperature effect on the xanthate’s performance during chalcopyrite flotation. Firstly, a macro-scale study was initiated to investigate the temperature effect on the hydrophobicity of mineral surface by means of contact angle measurement, Hallimond tube microflotation and lab flotation tests; secondly, a micro–scale study was conducted to clarify the temperature effect on the adsorption of chemicals on mineral surface employing an atomic force microscope (AFM) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR). In the experiments, pure chalcopyrite samples were used for contact angle measurement, Hallimond tube microflotation, AFM and FTIR; and copper ore samples (1.51% Cu, 5.88% Fe 0.029% Mo, 5.23% S in weight percentage) were used for lab flotation tests. FTIR spectra and AFM images showed that, when potassium amyl xanthate (PAX) was used as the collector in this study, oily dixanthogen was the main hydrophobic species on the chalcopyrite surface. The morphological change of dixanthogen patches at elevated temperatures has a more significant impact than changes in the amount of adsorption species. Increasing temperature within a certain range is beneficial for the collector’s performance by increasing flotation recovery.

Effects of Sodium Alginate on the Flotation Separation of Molybdenite From Chalcopyrite Using Kerosene as Collector.

In this paper, the effect of sodium alginate (SA) on the flotation separation of molybdenite (MoS2) from chalcopyrite using kerosene as collector was systematically investigated. The results of single-mineral micro-flotation tests indicated that SA exhibited strong depression on chalcopyrite flotation while it imposed no impact on the floatability of molybdenite. However, in the chalcopyrite–molybdenite mixed-mineral flotation system, the presence of chalcopyrite significantly increased the depressing effect of SA on molybdenite flotation, leading to a considerable reduction in the flotation selectivity. The negative impact of chalcopyrite on the performance of SA in molybdenite flotation was eliminated by adding a certain dosage of kerosene prior to SA. A concentrate containing 53.43% of molybdenum (Mo) was obtained at 76.90% of recovery using 19 mg/L kerosene and 40 mg/L SA at pH 5.4. Zeta potential measurements indicated that the adsorption of SA on chalcopyrite surfaces was stronger than that on molybdenite surfaces, which agreed with the single-mineral flotation test results. The adsorption of SA on chalcopyrite was further confirmed to be chemisorption by Fourier-transform infrared spectroscopy (FTIR) spectra analyses. When Cu2+ appeared in solution, the flotation of molybdenite was strongly depressed by SA. Mechanism analyses indicated that more active sites were generated on molybdenite surfaces after the addition of Cu2+, thus promoting the adsorption of SA.

Selective depression of talc in chalcopyrite flotation by xanthan gum: Flotation response and adsorption mechanism

Being a common gangue mineral in many sulfide deposits, naturally hydrophobic talc needs to be depressed by adding depressants. In this paper, xanthan gum was introduced as a selective depressant for talc. The effect of xanthan gum on the flotation separation of chalcopyrite from talc has been studied, and the interaction mechanism between xanthan gum and talc has been investigated. Micro-flotation results show that xanthan gum severely depresses talc flotation but barely affects chalcopyrite flotation at pH 8. In artificially mixed minerals flotation, a concentrate containing 31.87% Cu can be obtained at 90.03% Cu recovery from a feed of 16.94% Cu, indicating xanthan gum as a selective depressant. The effect of xanthan gum was also verified by the real ore flotation tests. The zeta potential measurements and adsorption measurements indicate that xanthan gum selectively adsorbs on talc surface. The results of XPS measurements and adsorption measurements illustrate that the adsorption of xanthan gum on talc surface occurs through physical interaction and hydrophobic interaction is considered as the main driving force. AFM images show that xanthan gum adsorbs on talc surface in a network structure with a layer thickness of 5.4 nm and coverage of 53.57%.

Flotation separation of molybdenite from chalcopyrite using ferrate(VI) as selective depressant in the absence of a collector

The effect of ferrate on the flotation of chalcopyrite and molybdenite in the absence of a collector was studied in this work. Flotation tests on single minerals revealed that chalcopyrite was strongly depressed by the ferrate for pH ranging from 4 to 9, whereas molybdenite was only slightly affected. The flotation tests on mineral mixtures and real ore confirmed that ferrate could selectively depress chalcopyrite flotation without significantly affecting molybdenite floatation. Under the optimum conditions, a value of >60% was obtained for the difference between the recovery of chalcopyrite and molybdenite. X-ray photoelectron spectroscopy results revealed that the oxide and hydroxide content and iron content of the chalcopyrite surface increased from 55.42% to 74.80% and 2.56% to 5.15%, respectively. This confirmed that the ferrate-treated chalcopyrite surface was more hydrophilic than the untreated surface. Therefore, ferrate can be used as a selective depressant of chalcopyrite in copper-molybdenum separation within a wide pH range.

Electrochemical mechanism and flotation of chalcopyrite and galena in the presence of sodium silicate and sodium sulfite

The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate, respectively, as a single depressant and their mixture as a combined depressant. Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant (>80%) within the studied dosage range. Galena flotation was severely depressed with descending depressing order as follows: combined depressant > sodium silicate > sodium sulfite. Electrochemical analysis confirmed the high affinity of depressants on the galena surface, resulting in the formation of hydrophilic species, such as lead sulfite, lead sulfate, and lead orthosilicate. The oxidation of chalcopyrite sutrface and depressants did not exhibit any signals; conversely, the self-oxidation of chalcopyrite was depressed. The results of cyclic voltammograms well agreed with flotation results, demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.

3-Mercaptopropionic/3-Mercaptoisobutyric Acids Used as Novel Selective Depressants for Improved Flotation of Chalcopyrite from Galena

The selective separation of chalcopyrite from galena (lead sulfide) through the flotation method is still a challenging task in the field of mineral engineering. Mercaptoacetic acid, though a common depressant of many gangue (commercially worthless) minerals, has shown to be less selective in the flotation separation of chalcopyrite and galena. This resent study therefore systematically investigated the selectivity of different mercapto acids (especially three types: 3-mercaptopropionic acid, 3-mercaptoisobutyric acid and mercaptoacetic acid) on the separation of chalcopyrite and galena by making the use of flotation experiments and first principle calculations. The calculation results demonstrated that the sulfhydryl and carboxyl groups existing on the molecular structure of three mercapto acids are the reactive and chelating centers to metal ions on sulfide mineral surfaces. Mercapto acids have higher binding energies to Cu2+ by 300–400 kJ/mol compared to Pb2+, indicating a higher affinity towards chalcopyrite. The order of reactivity and chelating ability noted was as follows: 3-mercaptopropionic acid > 3-mercaptoisobutyric acid > mercaptoacetic acid. Flotation results further showed that the selectivity of 3-mercaptopropionic acid or 3-mercaptoisobutyric acid was better than mercaptoacetic acid. The good agreement between the first principle calculations and the flotation results demonstrated that the former reagent could be served as a most selective depressant in the improved flotation separation of chalcopyrite and galena.

A novel copper depressant for selective flotation of chalcopyrite and molybdenite

In this work, the effect of Na2S2O3 and the mixture of Na2S2O3 and Cu2+ on the selective flotation performances of chalcopyrite and molybdenite were investigated through single and mixed mineral flotation tests. The depression mechanisms were studied in detail through Zeta potential, contact angle, XPS and Raman measurement. The results indicated that Na2S2O3 had more powerful depression effect on chalcopyrite than that on molybdenite. The depression could be greatly enhanced with the addition of Cu2+ without losing selectivity. XPS and Raman measurement revealed that Na2S2O3 and Cu2+ chemically adsorbed on chalcopyrite surface, formation of CuS which was responsible for the depression. On the other hand, the surface of molybdenite was slightly affected after the treatment in the mixed solution of Na2S2O3 and Cu2+. This new depressant had the advantage of low cost and environment friendly over conventional depressant, which could be utilized as an alternative depressant for the selective flotation separation of chalcopyrite and molybdenite.

Inhibited mechanism of carboxymethyl cellulose as a galena depressant in chalcopyrite and galena separation flotation

Carboxymethyl cellulose (CMC) is a highly efficient, nontoxic, and biodegradable depressant in Cu-Pb separation. However, poor understanding of the interaction mechanism has hindered the application of CMC in this separation process. Herein, galena was entirely inhibited by 250 mg·L−1 CMC at pH above 10, with minor effects on chalcopyrite flotation. As confirmed in zeta potential tests, CMC adsorbed much more easily to galena than chalcopyrite. The adsorption kinetics of CMC on galena was best described using a pseudo-second-order model dominated by chemisorption. In the presence of CMC, 74.4% of the electrochemical reaction sites on galena were inhibited and the resistance of the galena electrode surface film dramatically increased from 3838.7 to 17547.5 Ω·cm2. The likely mechanism of CMC adsorption on galena is competitive adsorption between CMC and sulfate to Pb2+.

The Auxiliary Effect of Copper Ions on the Depressant Effect of Sodium Thioglycolate in Chalcopyrite Flotation

Sodium thioglycolate is a chalcopyrite depressant, but its depressant effect is weak. The paper investigated the effect of CuSO4 on the depressant performance of sodium thioglycolate towards chalcopyrite through flotation tests, Zeta potential measurements, X-ray photoelectron spectroscopy (XPS) analyses and Fourier-transform infrared (FTIR) spectra measurements. It was found that copper ions could improve the depressant effect of sodium thioglycolate on chalcopyrite. The results showed that copper ions could adsorb on the surface of chalcopyrite and form mixed copper sulfide and cupric oxides/hydroxides adsorption layers. As a result, the mineral composition on the chalcopyrite surface was changed. With sodium thioglycolate treatment, the Zeta potential and the adsorption sites of chalcopyrite surface were both increased, and the hydrophobic substance Sn2−/S0 concentration was decreased. The electrostatic repulsion of chalcopyrite surface with sodium thioglycolate was also decreased, which made the sodium thioglycolate interact with chalcopyrite more easily. The more active sites could adsorb more sodium thioglycolate, which improved the hydrophilia of chalcopyrite. At the same time, the decrease of Sn2−/S0 concentration could further improve the hydrophilia of chalcopyrite. The results show that the copper ions could exhibit auxiliary effect with sodium thioglycolate and could further enhance the depressant effect of sodium thioglycolate on the chalcopyrite flotation. This paper provides new insights into the depression of chalcopyrite flotation by sodium thioglycolate.

The effect of sodium hydrosulfide on molybdenite flotation as a depressant of copper sulfides

Depressing copper sulfides using sodium hydrosulfide (NaHS) in the flotation of molybdenite is a common practice. However, the effect of NaHS on the flotation of molybdenite is not clear despite a number of studies. In this study, the effect of NaHS concentrations which depressed the flotation of chalcopyrite on the flotation of molybdenite of different particle sizes was investigated. It was found that molybdenite flotation was promoted at a low NaHS concentration. A high NaHS concentration only reduced the flotation kinetics slightly without affecting the final flotation recovery. The effect of NaHS on the flotation of smaller molybdenite particles was more significant. Cryo-XPS analysis was then carried out to understand the underpinning mechanism. It was evident that the flotation behavior of molybdenite in the presence of NaHS was determined by the reactions of NaHS on the edge plane surface of molybdenite. At a low NaHS concentration, NaHS adsorbed on the edge plane surface and formed hydrophobic species such as elemental sulfur and polysulfide. At a high NaHS concentration, the hydrophobic species disappeared with more HS− adsorbed. At both low and high NaHS concentrations, NaHS did not adsorb on the basal plane surface of molybdenite which remained its surface hydrophobicity.

Xanthate interaction and flotation separation of H2O2-treated chalcopyrite and pyrite

Abstract This study investigated the effects of H2O2 treatment on xanthate interaction and flotation separation of chalcopyrite and pyrite by making use of a series of laboratory flotation experiments and surface analysis techniques. Flotation test results showed that H2O2 treatment influenced the flotation behaviors of the two minerals; however, flotation of pyrite was depressed more significantly than that of the chalcopyrite. Under well-controlled H2O2 concentration, the selective separation of chalcopyrite from pyrite was realized at pH 9.0, at which the recovery of chalcopyrite was over 84% and that of pyrite was less than 24%. Zeta potential, UV−visible and IR spectrum measurements revealed that the collector interacted differently with the two minerals after H2O2 treatment, and the surface of chalcopyrite adsorbed much greater amount of xanthate than that of the pyrite. IR and XPS analyses showed that the H2O2 treatment significantly changed the surface properties of pyrite to very hydrophilic species that inhibited the adsorption of collector and thus depressed the floatability of pyrite. While, the surface of chalcopyrite remained mildly inert to H2O2, as a result, the adsorption of xanthate and its oxidation to dixanthogen were very effective, which enhanced the flotation of chalcopyrite.

Seaweed glue as a novel polymer depressant for the selective separation of chalcopyrite and galena

The use of seaweed glue (SEG) as a novel polymer depressant for the separation of chalcopyrite from galena with butyl xanthate (BX) as a collector was studied through microflotation experiments. Contact angle, adsorption, dynamic potential, and infrared spectral analyses were conducted to clarify the mechanism underlying the action of SEG on minerals. The results of microflotation experiments indicated that chalcopyrite could be selectively separated from galena by using a SEG depressant concentration of 15 mg·L−1, BX concentration of 10 mg·L−1, and methyl isobutyl carbinol concentration of 8.5 mg·L−1 at pH 8.0. A Cu concentrate with a grading of 23.68wt% was obtained at a recovery rate of 81.52% from mixed minerals with 8.29wt% Cu content. Contact angle analysis showed that the effect of SEG on the wettability of galena was stronger than that on the wettability of chalcopyrite. Adsorption, zeta potential, and FT-IR spectral analyses revealed that SEG and BX were coadsorbed on the surfaces of galena. SEG depressed galena by covering xanthate ions in the functional groups of -COO and mainly underwent weak physisorption on chalcopyrite. These mechanisms account for the ability of SEG to depress galena effectively while enabling chalcopyrite flotation.

Synthesis of thioxopropanamide surfactants for studying the flotation performance and adsorption mechanism on chalcopyrite

In this paper, three thioxopropanamide surfactants 3-ethylamino-N-methyl-3-thioxopropanamide (EAMTXPA), N,N-dimethyl-3-(phenylamino)-3-thioxopropanamide (PhATXPA) and 3-ethylamino-N-phenyl-3-thioxopropanamide (EAPhTXPA) were synthesized and introduced as collectors for chalcopyrite flotation for the first time. The chemical reactivity sites of thioxopropanamides was predicted by density functional theory. Micro-flotation tests show that EAPhTXPA possesses better flotation ability to chalcopyrite than EAMTXPA or PhATXPA. The contact angle tests showed that after treatment by the three thioxopropanamides, the contact angle of water drop on chalcopyrite increased. Furthermore, the hydrophobization intensity of EAPhTXPA toward chalcopyrite was stronger than that of EAMTXPA or PhATXPA. The adsorption mechanism of EAPhTXPA onto chalcopyrite was evaluated by adsorption tests and XPS analysis. Adsorption experiments indicate that the adsorption of EAPhTXPA is a spontaneous-endothermic chemisorption process. XPS spectra infer that the S, O and N atoms of EAPhTXPA may bond with the Cu atoms on chalcopyrite surfaces.

The differential depression of an oxidized starch on the flotation of chalcopyrite and graphite

It is difficult to achieve a clean separation during flotation when unwanted graphitic material exists in association with valuable copper sulphides such as chalcopyrite. Attempts to improve the separation has been driven by green and innocuous reagents such as starch or its derivatives to ensure environmental sustainability. In this study, the depressive action of an oxidized wheat starch in comparison to the normally used native counterpart during flotation of chalcopyrite and graphite was investigated. Starch oxidation, depending on the degree, yields an uncommon phenomenon of concurrent depolymerisation of the large supramolecular assembly of starch chains as well as generation of CO (carbonyl) and (COO) carboxyl moieties on the starch matrix. Adsorption and AFM imaging measurements were performed and correlated with flotation recovery to probe into the influence of the structural and functional changes due to starch oxidation. The base material (native wheat starch – NWS) exhibited a similar adsorption response on chalcopyrite and graphite with increasing polymer concentration, which corresponded to their similar depression during flotation. However, the oxidized starch (Ox 5/120) produced in the laboratory resulted in significant depression of graphite with a modest effect on chalcopyrite flotation. Ox 5/120 also showed marked differences in adsorption behaviour between graphite and chalcopyrite in consonance with the flotation results. It is clear that starch oxidation has an intriguing effect on the underlying binding mechanisms and conformations at mineral surface governing the separation efficiency.