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EN
The present study investigates the effects and mechanisms of aluminum (Al(III)) and iron (Fe(III)) ions on the flotation efficiency of potassium feldspar (K-feldspar) within oleate collector systems. The study employs micro-flotation experiments, solution chemistry calculations, zeta potential measurements, and FT-IR and XPS analyses to demonstrate that Al(III) and Fe(III) ions can significantly improve the flotation recovery of K-feldspar by altering its surface charge, bonding properties, and adsorption modes. The study also develops adsorption models for the flotation of K-feldspar activated by Al(III) and Fe(III), revealing the synergistic impacts of metal ion hydrolysis products and sodium oleate in the formation of hydrophobic complexes.
EN
The nature and mechanism of interaction between carboxymethyl cellulose (CMC) with cassiterite (and chlorite surfaces) and their effects on the flotation separation process of cassiterite (from chlorite) were investigated by micro-flotation tests, surface adsorption experiments, zeta potential measurements, solution chemical calculation, infrared spectroscopy, and X-ray photo-electron spectroscopy (XPS). The results from single mineral tests revealed that CMC exhibited good selective inhibition effects with cassiterites and chlorites. When the dosage was 12.5 mg/L at pH 8, cassiterite and chlorite recovery was 92.2% and 6.3%, respectively. The artificial mixed ore test revealed that the flotation separation effect was the best when the dosage of CMC was 6.5 mg/L. Cassiterite used during the studies was 75.1% pure. The recovery was 82.8%. The interaction between CMC and the cassiterite surface led to a shift in the zeta potential toward the negative direction. CMC was weakly adsorbed on the cassiterite surface. There was no significant impact on the subsequent collection of sodium oleate. The concentration of C atom increased post interaction, and the potential shifted toward the negative direction. Characteristic CMC peaks were observed at this point. Hydrogen bonds and weak chemisorption interactions between CMC and chlorite affected the interaction between sodium oleate and the chlorite surface. It also affected the flotation results. The cassiterite and chlorite were separated effectively.
EN
The effective flotation separation of sulfides and sliming silicate minerals is always a difficult problem. In this paper, the selective flotation of arsenopyrite from muscovite was studied by using sodium phytate (SP) as dispersant, and the mechanism was investigated through SEM/EDS, zeta potential, FTIR and XPS measurements. Single mineral flotation results showed that with the increasing isoamyl xanthate (IAX) dosage the recovery of arsenopyrite increased, until 8×10−5 mol/L IAX (79.40% recovery, pH=7), after that it decreased slightly. While muscovite floated poorly at any IAX concentration. For the mixed minerals, arsenopyrite recovery was only 54.63% while that of muscovite was 42.70%, which was attributed to the coverage of muscovite on arsenopyrite surface. When 6×10−5 mol/L SP was added into the mixed minerals system, the recovery of arsenopyrite recovered to 68.26% while that of muscovite was 8.48% (approximate the value of the single mineral). SEM/EDS results showed that SP could disperse muscovite and prevented its coverage on arsenopyrite surface. Zeta potential results showed that the electrokinetic potential of muscovite and arsenopyrite decrease from -26.60mV to -39.01 mV and from -26.90 mV to -27.84 mV at pH=7, respectively. It was obvious that the negatively charged phytate ions selectively adsorbed on the surface of muscovite. FTIR and XPS resulted co-proved the chemisorption of SP with active sites on muscovite while arsenopyrite spectrum did not change significantly, which was consistent with flotation and zeta potential results. The selective adsorption of SP on muscovite compared to arsenopyrite was responsible for the effective separation of them.
EN
In this paper, sodium oleate, polyacrylamide, soluble starch and sodium carboxymethyl cellulose were used as flocculants to study the flocculation and sedimentation behavior of microfine ilmenite. Sedimentation test shows that sodium oleate and polyacrylamide have good flocculation effect on ultrafine ilmenite. The flocculation rate of ilmenite can be further improved by the combination of sodium oleate and polyacrylamide. It was found that both flocculants could generate chemical adsorption with ilmenite surface, and they all react with Fe3+ on ilmenite surface. However, sodium oleate reacts with Fe3+ to form a water-insoluble iron oleate precipitate which coats the surface of the ilmenite and hinders the action of polyacrylamide and the remaining Fe3+. This problem can be avoided by adding polyacrylamide followed by sodium oleate, and the flotation recovery can be increased significantly.
EN
In this paper, on the basis of a modified Washburn equation, the squared incremental pressure due to liquid rising vs. time were measured instead of wicking distances before reaching equilibrium, and the relative wetting contact angles (RWCA) were applied to characterize the surface wettability of quartz particles conditioned at different concentrations of flotation reagents. Combined with the flotation experiments on quartz particles at corresponding conditions, the relationship between flotation recoveries and RWCA was analysed, which proves that RWCA can characterize the surface wettability of quartz particles accurately. The results also showed that the best reagent conditions for floating quartz are pH 12.0, a Ca2+ concentration of 1×10-3 mol/dm3 and a sodium oleate concentration of 0.75×10-3 mol/dm3, where the recovery of quartz is 86%. The surface tension of the filtrate of the pulp was determined by a fully-automatic tensiometer as well. Based on the measured values of RWCA and surface tension, the free energy changes (ΔG) before and after the adhesion of bubbles and particles per unit area at corresponding situations were calculated, respectively. The trends of ΔG varying with the concentrations of reagents were in close accordance with those of RWCA and the flotation recoveries, proving that it is more likely for particles having bigger contact angles to adhere to bubbles, resulting in a higher flotation recovery. These results give a more feasible and accurate approach to analysing the surface wettability and floatability of fine particles.
EN
Witherite has been widely used as an industrial and environmental source of barium, with calcite being the primary associated carbonate mineral. However, few studies have been conducted to effectively concentrate witherite from barium ores. In this work, with the treatment of potassium chromate (K2CrO4) and sodium oleate (NaOL), witherite was selectively separated from calcite through selective flotation at different pH conditions. In addition, contact angle, Zeta potential, adsorption and X-ray photoelectron spectroscopy measurements were performed to characterize the separation mechanisms. The results demonstrated that NaOL had a strong collecting ability for both witherite and calcite; nevertheless, witherite could be effectively selected from calcite with the highest recovery at pH 9 in the presence of K2CrO4. From the XPS measurements, NaOL and K2CrO4 were found to be primarily attached to the surfaces of witherite and calcite through chemisorption. The presence of K2CrO4 on the surface of calcite adversely influenced the NaOL adsorption, which could make the flotation separation efficient and successful.
EN
In this study, the surface properties and flotation behavior of quartz with NaOl as a collector in the presence of Ca2+ ions were investigated using density functional theory (DFT) calculations in conjunction with flotation tests, adsorption experiments, zeta potential measurements, and solution chemistry calculations. The results of the flotation and adsorption tests proved that Ca2+ promoted the flotation recovery and the adsorption density of sodium oleate on quartz at pH > 8. Zeta potential analyses and solution chemistry calculations demonstrated that Ca(OH)+ was the functional species which activated quartz. DFT calculations indicated that O atoms dominated the quartz (101) surface, and great electrostatic repulsion and space resistance existed between the surface and oleate anion.The spontaneous adsorption of H2O and OH- on the (101) surface made quartz surfaces hydrated and hydroxylated, and resulted in the hydrophilicity of quartz. The adsorption of Ca(OH)+ on quartz (101) surface was more favorable and able to repulse the water film, which decreased the electrostatic repulsion and space resistance, and further facilitated the adsorption of oleate anion. During the activating and collecting adsorption processes, electron transition occurred along the O1—Ca—O2 path, implying Ca(OH)+ acted as an intermediary and electron donator in the activation process.
EN
The performance of the mixed anionic (sodium oleate) / nonionic (sorbitan monooleate) collectors on fergusonite flotation and separation from silicate gangue minerals was investigated using the flotation tests. The surface characterization of fergusonite before and after the treatment with the mixed collectors was determined using the zeta-potential measurements and FT-IR analyses. The results obtained from this study showed that the flotation recovery of fergusonite using sodium oleate enhanced in the presence of sorbitan monooleate, and the optimum floatability was achieved at pH 5 using 1 Kg/Mg blended collectors of sodium oleate and sorbitan monooleate as by a ratio 1:1 and methyl isobutyl carbinol (MIBC) as a frother. It was also found that the addition of sodium metasilicate to citric acid as a depressant showed a high affinity for silicate gangue minerals and weak affinity for fergusonite. The zeta-potential and FT-IR measurements of fergusonite after the treatment with the mixed collectors indicated a strong adsorption of these molecules on the particle surface due to chemisorptions. Additionally, The SEM analysis of high grade froth and its corresponding tailing product showed that the fergusonite mineral mostly concentrated in the froth, while the gangue silicate minerals relatively concentrated in the tailing. Finally, synergistic interaction between the anionic and nonionic surfactants was observed during adsorption on fergusonite and was succeeded for separation from its gangue silicate minerals.
EN
Micro-flotation and batch flotation tests were carried out on fine (-20 µm) hematite to investigate the influences of non-polar oil when sodium oleate, octyl hydroxamic acid, or oleoyl hydroxamic acid was used as a collector. Both micro-flotation and batch flotation tests were performed using single hematite mineral and/or artificial mixed minerals (hematite:quartz = 1:1), and kerosene was utilized as the neutral oil. The experimental results showed that the addition of a kerosene emulsion benefited hematite recovery in the micro-flotation tests where a froth layer did not exist. In the batch flotation where a froth layer existed, kerosene behaved differently when used in conjunction with the three collectors. Kerosene helped improve the batch flotation when sodium oleate or oleoyl hydroxamic acid was used as a collector. However, it reduced concentrate weight yield, grade and recovery to a noticeable extent when octyl hydroxamic acid was used as a collector, especially at low dosages. In addition, single hematite batch flotation kinetics tests coupled with water recovery measurement were carried out to study the role of kerosene at different collector dosages. It was observed that water drainage and the resulting froth destabilization by kerosene was dominant at low collector dosages, especially in the flotation using octyl hydroxamic acid. At higher collector dosages, the water drainage and froth destabilization effect by kerosene was possibly counter-balanced by the higher hematite surface hydrophobicity and bubble surface tension gradient, which led to more stable froth layer.
EN
The emulsified sodium vegetable oleate (ESVO) was prepared with low-cost vegetable oleate. Using ESVO as a collector, the flotation performance of fluorite had been investigated comparing with sodium oleate at a temperature of 20 ± 2 °C. The results of flotation showed that ESVO had better collecting performance than the sodium oleate. The interaction mechanism of these two collectors with fluorite was studied by the zeta potential, FTIR spectra and laser grain-size tests. Both ESVO and sodium oleate changed fluorite zeta potential by electrostatic attraction and chemical adsorption, and generated calcium carboxylate on the fluorite surface. Moreover, it was concluded that higher fluorite recovery was a consequence of ESVO smaller surface tension comparing to sodium oleate.
EN
Properties of anosovite in titanium slag, anosovite flotation response in a collector solution of sodium oleate, and adsorption behaviour of sodium oleate on the mineral surface were studied in the present work using XRD, Raman spectra, flotation tests, zeta potential analysis, FTIR and XPS. The results show that the anosovite crystal contains magnesium, and its chemical composition is Mg0.09Ti2.91O5. The chemical bonds on the anosovite surface mainly comprise Ti-O bonds. Micro-flotation tests indicate that anosovite has better floatability at a wide pH range and the recovery reaches 88% at pH=6, when the dosage of sodium oleate is only 4·10−6 mol/dm3. The point of zero charge of anosovite was determined near pH 3.2 by the zeta potential measurement. In the flotation process, chemical adsorption occurs between the carboxyl of sodium oleate and the titanium sites on the anosovite surface.
EN
Quartz Crystal Microbalance with Dissipation (QCM-D) was firstly applied to investigate the adsorption mechanism of sodium oleate on TiO2 coated sensor surface. The effects of pH value, sodium oleate concentration, and temperature on TiO2 coated sensor surface were evaluated systematically using the QCM-D technique. Zeta potential, surface tension, adsorption isotherms, and adsorption thermodynamics were employed to characterize the adsorption process. The results showed the advantages of QCM-D on the investigation of the adsorption process. Additionally, the electrostatic equilibrium adsorption data was well matched to the Langmuir isotherm. Based on the thermodynamic analysis, adsorption was a spontaneous and endothermic physisorption process.
EN
Several studies revealed that flotation of wolframite changes with different Fe/Mn ratios, but they did not reach a consensus. This relationship in the presence of benzohydroxamic acid (BHA) and sodium oleate (NaOl) as collectors was studied in this paper through comparison of probability distribution curve of wolframite with different Fe/Mn ratios between the raw ore and the flotation concentrate, the pure mineral flotation and solution chemistry of flotation. The results showed that wolframite with high Fe/Mn ratio showed higher flotation with BHA as a collector while the flotation behavior of wolframite was completely opposite with NaOl as a collector. Besides, the calculations of chemical equilibrium in the solution were plotted as ΔG°-pH graphs. The results revealed that the flotation of wolframite may be determined by the interaction between BHA and ferric(II) ion or between NaOl and manganous ion. From the perspective of collector mixture, the results also explain the high collecting capability of the BHA/NaOl collector mixture, which can be defined as “functional complementation”.
EN
Chromite recovery was studied using a magnetic carrier technology. Heavy media grade magnetite was used as the magnetic carrier. The effect of various reagents such as sodium oleate (NaOl) as a collector and carboxymethyl cellulose (CMC) as well as quebracho tannin as depressants on chromite removal was investigated. The effects of pH and reagent dosages were also determined. First, the zeta potential measurements were performed for different minerals in the absence and presence of NaOl, and then magnetic carrier tests were carried out under conditions based on zeta potential measurements. The magnetic carrier tests performed in the case of individual minerals (i.e. single minerals) showed that chromite (recovery of 95.1%) could be separated from serpentine (recovery of 3.2%) whereas it could not be separated from olivine. The best chromite concentrates containing 42.1% Cr2O3 were obtained with a 76% recovery from a synthetic mixtures of chromite and serpentine under optimum test conditions, that is at pH 10.5, 5.10–5 M NaOl, 20 g/Mg CMC, 0.5 g magnetite and 500 g/Mg kerosene (the feed contained 27% Cr2O3). Slime tailings of Turkish Maadin Company, Kavak Chrome Concentrating Plant in Eskisehir, which contain fine chromite, serpentine and olivine, were also investigated. It was found that chromite could not be satisfactorily recovered from the original slime sample in the presence and absence of NaOl by using the magnetic carrier technology. Additional FTIR studies performed with the investigated minerals showed that NaOl adsorption on chromite was greater than that on serpentine and magnetite minerals. It was also found that NaOl adsorption on serpentine is significantly reduced in the presence of magnetite while it increases only slightly on chromite.
15
Content available remote Micro-floatability of rutile and zircon with soap and amine type collectors
EN
Single-mineral floatability of pure, heavy sand rutile and zircon minerals using sodium oleate and hydrogenated tallow amine acetate as collectors was studied by a micro-flotation device over a wide pH range from 2 to 12, at three levels of the collectors and two levels of a polypropylene glycol type frother. Rutile yielded a peak foatability at pH 6 with sodium oleate, and floated reasonably well over a wide pH range from 2 to 8 with the amine collector. An abrupt deterioration of the floatability of rutile was observed at pH>8. The maximal floatability range for zircon was from pH 6 to 10, followed by a sharp decrease at pH>10, with both of the collectors. The floatability of zircon decreased sharply with decreasing pH in the acidic medium, below pH 6. The results were discussed in view of collector species distribution as a function of pH to suggest adsorption mechanisms for the collectors. The upper critical flotation pH values for the minerals seemed to be sufficiently distinct to suggest a potential for the differential flotation of the minerals in the alkaline medium with both of the collectors tested.
PL
Flotowalność czystych minerałów rutylu i cyrkonu badano przy pomocy testów mikroflotacyjnych. Kolektorami w procesie flotacji były oleinian sadu i octan talowej aminy. Badania flotacyjne prowadzono w zakresie pH od 2 do 12, stosując trzy różne stężenia kolektora i dwa stężenia odczynnika pianotwórczego (glikol polipropylenowy). Rutyl wykazywał maksimum flotowalności przy pH 6, przy użyciu jako kolektora oleinianu sodu. Stosując kolektor aminowy dobre wyniki flotacji rutylu uzyskano w zakresie pH od 2 do 8. Wyraźny spadek flotowalności obserwowano przy pH>8. Maksymalna flotowalność cyrkonu, przy użyciu obu kolektorów, była w zakresie pH 6-10. Flotowalność cyrkonu malała szybko przy pH>10. Równie, wyraźny spadek flotowalności cyrkonu obserwowano w środowisku kwaśnym pH poniżej 6. Otrzymane wyniki z flotacji zostaly przedyskutowane w oparciu o prawdopodobne mechanizmy adsorpcji badanych kolektorów do powierzchni minerałów. Różnice w flotacji minerałów w obszarze alkalicznym sugeruja możliwość separcji tych minerałów przy zastosowaniu badanych kolektorów flotacyjnych.
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