Single Mineral Flotation Tests Research Articles

Study on the Effect of Fe3+ on Zircon Flotation Separation from Cassiterite Using Sodium Oleate as Collector

The effect of ferric ions (Fe3+) on the flotation of zircon and cassiterite using sodium oleate (NaOL) was investigated by single mineral flotation tests, adsorption density tests, zeta potential measurements, solution chemistry analyses, and FTIR analyses. It is difficult for zircon to be separated from cassiterite by using NaOL alone. Nevertheless, the flotation of zircon was activated while that of cassiterite was depressed in the presence of Fe3+. Adsorption density tests indicated that the addition of Fe3+ enhanced the adsorption of NaOL on zircon surfaces, whereas it receded on cassiterite surfaces. Zeta potential measurements and solution chemistry analyses found that H(OL) 2 − was the predominant species to determine the flotation behaviors of zircon and cassiterite. Furthermore, the addition of Fe3+ at pH < 8 reduced the negative charges on the zircon and cassiterite surfaces. It was confirmed that the positive charges of zircon were caused by the positively charged species of Fe3+, including Fe3+, Fe(OH)2+, and Fe(OH) 2 + . Meanwhile, these results revealed that the hydroxy complex and the precipitate of Fe(OH)3(s) adsorbed onto the cassiterite surfaces caused the flotation of cassiterite to be inhibited. It can be concluded from FTIR analyses that the peaks of zircon at 894.14 cm−1 and 611.65 cm−1 were strengthened and the adsorption on zircon surfaces was found to be chemisorption due to the addition of Fe3+, whereas both chemical and physical adsorptions of NaOL on cassiterite surfaces were weakened, resulting in the different flotation behaviors of zircon and cassiterite in the presence of Fe3+.

Removal of fine quartz from coal-series kaolin by flotation

Coal-series kaolin (CSK) in Xuzhou, Jiangsu Province of Eastern China was characterized by chemical analyses, X-ray diffraction (XRD) and zeta potential measurement as well as by scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS). The authigenic ultrafine quartz grains (d90=15.8μm) closely associated with this CSK sample was the major impurity mineral, which cannot be separated from kaolin by screening and size classification process. This work investigated the separation of fine quartz from kaolin by flotation. Single mineral flotation tests indicated that effective separation of quartz from kaolin was possible with acidic pH value (pH=3), depressant of starch and collector of dodecyl amine (DDA). Rougher flotation tests of coal-series kaolin revealed that the SiO2/Al2O3 weight ratio of the concentrate was qualified for industrial applications in the presence of 160g/t starch and 100g/t DDA, at acidic pH pulp. A specially designed two-stage cleaner flotation flowsheet increased the concentrate recovery from 37.26% to 46.55% compared to a rougher flotation process.

Application and Mechanism of Anionic Collector Sodium Dodecyl Sulfate (SDS) in Phosphate Beneficiation

Phosphate ore is a valuable strategic resource. Most phosphate ore in China is collophane. Utilization of mid-low grade collophane is necessary to maintain social sustainable development. The gravity-flotation combination separation process can be utilized to separate mid-low grade collophane, but the process consumes a large quantity of acid in the reverse stage. Sodium dodecyl sulfate (SDS) was used as a dolomite collector in this study to reduce the acid consumption of collophane flotation. SDS effectively removed dolomite from the gravity concentrate when no other reagents were present. Flotation test results showed that, compared to the conventional gravity-flotation process, the proposed SDS-based process reduced phosphoric acid dosage from 6.1 kg/t to 3.9 kg/t with similar separation results. The SDS action mechanisms on dolomite were further investigated by zeta potential analysis, single mineral flotation tests, infrared spectrum detection, and theoretical analysis. The results indicate that the SDS adsorption on dolomite is mainly physical adsorption, and that favorable separation effects between collophane and dolomite may be attributed to physical adsorption and entrainment. In addition, it also indicates that the physical adsorption can be utilized to remove dolomite from phosphate on account of zeta potential differences when the separate feed is coarse.

Electrochemical behavior of galena and jamesonite flotation in high alkaline pulp

In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were investigated. Single mineral flotation test was organized to research the effect of pulp pH value on the flotation behavior of galena and jamesonite. Electrochemistry property of the interaction of these two minerals with DDTC was investigated by cyclic voltammetry and Tafel tests. Flotation test shows that the recovery of jamesonite in high alkaline pulp is strongly depressed by lime (Ca(OH)2). The cyclic voltammetry and Tafel tests results show that the interaction between galena and DDTC is an electrochemical process. High pH value has little influence on the interaction between galena and DDTC, while it has great effect on jamesonite due to self-oxidation and specific adsorption of OH− and CaOH+ on jamesonite surface. Non-electroactive hydroxyl compound and low-electroconductive calcium compounds cover the surface of jamesonite, which impedes electron transfer and DDTC adsorption, thus leads to very low floatability of jamesonite.

Flotation separation of chalcopyrite from galena by sodium humate and ammonium persulfate

The flotabilities of chalcopyrite and galena with sodium humate (HA) and ammonium persulfate (APS) as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single mineral flotation test shows that the slurry oxidation environment and the proper oxidation of galena surface are prerequisites for the depression of galena by sodium humate. The closed-circuit flotation test of copper/lead bulk concentrate shows that the grade and recovery of Cu reach 30.47% and 89.16% respectively and those of Pb reach 2.06% and1.58% respectively in copper concentrate, and the grade and recovery of Pb reach 50.34% and 98.42% and those of Cu reach 1.45% and 10.84% respectively in lead concentrate with HA and APS. The selective depression effect of HA and APS is more obvious than that of potassium dichromate. The results of FTIR analysis and adsorption measurements indicate that the adsorption of sodium humate on the fresh surface of galena is negligible, while after oxidation, sodium humate can be chemically adsorbed on the surface of galena. According to the theory of solubility product, the sodium humate can display the oxidation product PbSO4, after then, adsorb on the surface of lead chemically to produce inhibitory effect. Thus, it can be seen that the combination of HA and APS is an efficient non-toxic reagent to achieve cleaning separation copper/lead bulk concentrate by flotation. The combination of HA and APS is an efficient non-toxic reagent to achieve cleaning for copper/lead bulk concentrate by flotation.

Influence of depressant foenum-graecum on the flotation of a sulfide ore which contains hydrophobic gangue

In this paper, the influence of the depressant foenum-graecum (FGM) on the flotation of a nickel sulfide ore which contains hydrophobic talc and chlorite was systematically investigated through single mineral flotation, bench-scale and industrial-scale flotation tests. The flotation results indicated that FGM had excellent depression selectivity for talc and chlorite minerals and little depression effect on copper–nickel minerals. Compared with the conventional depressant carboxymethyl cellulose, the FGM scheme increased the recovery of copper in Cu–Ni concentrates over 25% and nickel in Cu–Ni concentrates over 16% as well as simplified the structure of flotation process. In addition, the adsorption mechanisms of FGM on talc and copper–nickel minerals were studied by adsorption, zeta-potential and FTIR measurements, which further demonstrated that the adsorption of FGM on talc was much stronger than that on pentlandite, FGM could selectively adsorb on talc surfaces through chemical adsorption while a weak hydrogen bond or electrostatic attraction occurred between FGM and copper–nickel minerals.

Influence of bromine modification on collecting property of lauric acid

Bromine atom with strong electronegativity was introduced to α-carbon position of lauric acid (LA) by solvent-free method (Hell–Volhard–Zelinski reaction) at ambient pressure in laboratory, and the synthesized product α-Bromolauric acid (CH3(CH2)9CHBrCOOH, α-BLA) was used as a new type collector for the flotation of quartz mineral. The flotation properties of pure quartz using α-BLA as a collector were investigated by single mineral flotation tests. The adsorption mechanism of α-BLA collector on quartz surface was established by zeta potential measurements, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS), in conjunction with the results of quartz micro-flotation tests. Pure mineral flotation results showed that the collector α-BLA exhibited an excellent performance at alkaline conditions (pH⩾11.50), activator CaCl2 concentration 1.0×10−4mol/L, and collector concentration 1.5×10−4mol/L in a relatively lower temperature 15°C, where about 99.8% of the quartz could be floated out. Compared with collector LA, the new synthesized collector α-BLA is more tolerant to lower pulp temperature and fluctuations of the reagents dosages. The study revealed that the α-BLA collector had adsorbed on the surface of pure quartz in the forms of chemical interaction, electrostatic adsorption and hydrogen bonding adsorption based on the results of zeta potential measurements, FT-IR spectra, and XPS.

An investigation into the flotation of muscovite with an amine collector and calcium lignin sulfonate depressant

Muscovite mica is a naturally occurring phyllosilicate mineral with a wide range of industrial applications. This work investigated the separation of muscovite from unwanted gangue minerals in a mica ore. Electroacoustic zeta potential measurements and single mineral flotation tests were used to determine the effect of Custamine 8113 (collector) and Norlig-H (depressant) on muscovite. These results were then compared to those of gangue minerals (feldspar and quartz). Muscovite showed an isoelectric point (IEP) at pH 3.5. Feldspar and quartz did not have an IEP, having negative zeta potentials over the pH range investigated (pH 3–10). This suggests that effective separation using a cationic amine collector, which relies on electrostatic attraction as the basic mechanism of adsorption onto mineral surfaces, would not be possible without the use of a depressant. Zeta potential measurements and single mineral flotation tests in the presence of both Custamine 8113 and Norlig-H indicate that reagent adsorption is controlled by Custamine 8113 in the case of muscovite and by Norlig-H in the case of feldspar and quartz. This suggests that effective separation of muscovite from the gangue minerals present in the mica ore is possible. These results were used to determine optimal flotation conditions of the ore. Concentrates from the ore flotation were examined by QEMSCAN analysis, which showed that muscovite was effectively separated from gangue minerals.

Effect of nanoparticles on froth stability and bubble size distribution in flotation

In order to investigate the usability of nanomaterials as a froth stabiliser in mineral flotation, an experimental study was performed using a froth column and a modified flotation cell. Four different nanomaterials, namely SiO2, TiO2, Fe2O3 and Al2O3, were used in the experiments. The froth column tests were carried out to measure the Sauter-mean bubble size and dynamic froth stability under different operating conditions. Single mineral flotation tests with or without the nanomaterials were performed using a pure barite sample. Results of the froth column tests show that despite of the increasing froth height, the bubble coalescence in the froth or bursting on the surface can be decreased considerably by using the nanomaterials. The effect of the increase in froth height on the Sauter-mean bubble size and the bubble coalescence was found to be negligible by using the nanomaterials in all pH values used. These effects of the nanomaterials could not be attributed to both signs and magnitudes of their surface charges.It was determined that the nanomaterials used in this study did not contribute to the flotation efficiency at shallow froth. Contrary to this, the nanomaterials, in particular nano-sized Fe2O3 and Al2O3, provide a significant increase in barite recovery (7–11%) at deep froth, which means that selection of the type of the nanomaterials to be used in flotation is also important. As a result of the use of the nanomaterial, the decrease in the flotation performance at deep froths was found to be negligible.

The Experimental Study and Mechanism Analysis on Flotation Separation of Tetradymite and Pyrite

The experimental results of flotation of pure tetradymite and pyrite show that HL-1 is an efficient collector for tetradymite flotation. Comparing to the butyl xanthate, HL-1 has stronger collector ability and higher selectivity. It solves the common problem of the separation of tetradymite and pyrite. The difference of adsorption quantity is consistent with results of the single mineral flotation test. Through the measurements of adsorption, zeta-potential, and FTIR spectral analysis, the flotation mechanism of tetradymite with HL-1 has been discussed. It is concluded that the adsorption of HL-1 on tetradymite surface is chemical adsorption through the dithiocarbamate group of the collector chelating the Bi (III) of tetradymite to form metal complex.

Study on Flotation Separation of Muscovite and Kaolinite

The influence of dodecylamine acetate (DDA) and myristyl trimethyl ammonium chloride (1431) on the flotation behavior of muscovite and kaolinite were studied in this paper. The condition which can efficiently separate the muscovite and kaolinite was found out: 5×10-5mol·L-1~1×10-4mol·L-11431 as collector and pH=5.The feasibility of flotation separation in this condition was validated by artificial mixed minerals separation test. The results of zeta potential measurement, infrared spectrum analysis and adsorption quantity test show that 1431 was adsorbed on the surface on muscovite and kaolinite by static electricity adsorption. The difference of adsorption quantity was consistent with results of the single mineral flotation test.

A study on the interaction of feldspar and quartz with mixed anionic/cationic collector

Interaction studies of feldspar and quartz with a mixed cationic/anionic collector namely N-tallow 1,3–propylenediamine-dioleate (duomeen TDO) were carried-out. The interaction between collector and minerals has potential to change the surface properties from hydrophilic to hydrophobic. In this study the adsorption behaviour of duomeen TDO on feldspar and quartz was assessed through zeta potential (ζ) and contact angle (Ө) measurement as well as with Fourier transformed infra-red (FTIR) spectroscopy. The sample was collected from Apex Granite, Muar, Johor and thus sample characterization were also carried out such as X-ray diffraction (XRD) was used for qualitative analysis and field emission scanning electron microscopy (FESEM) in order to yield useful microscopic information. Zeta-potential results between pH 2 and pH 10 for feldspar and quartz were measured. When the zero negative value of quartz reached pH 2 the separation process of feldspar from quartz was more significant. By gradually adding duomeen TDO, the contact angle of feldspar and quartz were increased leading to enhance hydrophobicity, but decreasing its free energy and components (Lifshitz-van der Waals γsLW, Lewis electron-donor γs-, and Lewis electron-acceptor γs+). FTIR results showed that at various dosages of duomeen TDO, this collector adsorbed on feldspar and quartz surfaces in the bands characteristic of alkyl chains, vas (CH3), vas (CH2) and vs (CH2) groups between region of 3000-2800 cm-1. Moreover the intensity of the alkyl chain bands increased slightly higher for feldspar compared to quartz with increasing initial duomeen TDO concentration. Finally single mineral flotation tests using Hallimond tube were performed and it has been found that feldspar floatability increased with increasing concentration of duomeen TDO.

Study on Flotation Mechanism of Separation of Potassium Feldspar from Quartz with Anion and Cation Mixed Collector

Potassium feldspar and quartz are all silicate minerals with frame structure,and have the similar crystal structure and physicochemical properties. Therefore, flotation has become the main method to separate potassium feldspar from quartz. The separation of potassium feldspar from quartz with anion and cation mixed collector was studied in the paper. The sodium oleate and sodium dodecyl benzene sulfonate were respectively used as collector agents in potassium feldspar and quartz single mineral flotation tests. The analysis of the variation of the surface properties of potash feldspar and quartz after using the collectors was conducted with infrared spectra and electrokinetic potential, followed by the mechanism of separation of potassium feldspar from quartz with anion and cation mixed collector.

Adsorption Mechanism of Mixed Cationic/Anionic Collectors in Quartz–Hematite Flotation System

The adsorption mechanism of mixed cationic C12 amine and anionic sulfate / oleate reagent schemes was examined through Hallimond flotation studies using pure quartz and hematite minerals. The flotation response of both quartz and hematite with cationic and anionic collectors in isolation and with mixed cationic / anionic collector systems was evaluated as well. The flotation response as a function of pH and collector concentration was analyzed, wherein quartz was not responsive to floatation in single mineral flotation tests in the presence of anionic collectors but C12 amine flotation of quartz was observed to be pH and concentration dependent. Maximum hematite floatation recovery was observed at acidic pH with sulfate, neutral pH with oleate, and at basic pH about 9.5 with C12 amine. Accelerated adsorption of cationic collector in the presence of anionic collector apart from its own co-adsorption was observed in flotation results with quartz and hematite. Assimilation of oleate in between the C12 amine molecules retards the electrostatic head–head repulsion, thereby intensifying the adsorption of C12 amine due to attractive tail–tail hydrophobic bonds, besides forming a compact adsorbed layer with elevated hydrophobicity. Incremental oleate concentration beyond C12 amine concentration leads to the formation of soluble amine–oleate complex/precipitate and the adsorption of these species decrements the flotation since the alkyl chains are in chaotical orientation with conceivable number of head groups propelling toward the solution phase.

Xanthation-modified polyacrylamide and spectroscopic investigation of its adsorption onto mineral surfaces

A xanthation-modified polyacrylamide (PAM), named PAM-X, was synthesized. In single mineral flotation tests, PAM-X exhibited unique selectivity between galena and Cu-activated sphalerite. The adsorption mechanisms were investigated via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). It was observed that PAM-X had different absorption band shifts when adsorbed onto galena and Cu-activated sphalerite, indicating the formation of different adsorption bonds between PAM-X and the minerals. The analysis by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) revealed that PAM-X was a mixture composed of partially hydrolyzed PAM and a low molecular weight sulfur-bearing compound. The observed selectivity of PAM-X to galena and Cu-activated sphalerite was attributed to the adsorption of the PAM-X and the synergistic effect of its two components.

Using chitosan as a selective depressant in the differential flotation of Cu–Pb sulfides

Chitosan, a natural polymer extracted from crustacean shells, was found to selectively depress chalcopyrite while galena was floated by xanthate. At pH 4, the recovery of galena was up to 95% while that of chalcopyrite was 30% when flotation tests were carried out on mixtures of chalcopyrite and galena. However, in single mineral flotation and adsorption tests, it was found that both chalcopyrite and galena were depressed and chitosan adsorbed on both minerals. The observed selectivity seemed to have originated from competitive adsorption. ToF-SIMS measurements indicated that when chalcopyrite and galena were present together in the suspension, chitosan barely adsorbed on galena but adsorbed heavily on chalcopyrite. Chitosan-metal ions adsorption test, X-ray photoelectron spectroscopy (XPS) as well as ToF-SIMS were employed to study the interaction of chitosan with chalcopyrite and galena and to delineate the observed competitive adsorption. Chitosan could potentially be used in differential Cu–Pb sulfide separation to replace the hazardous inorganic depressants such as cyanide, dichromate and sulfur dioxide.

Effect of 2-aminothiophenol on the separation of jamesonite and marmatite

The minerals jamesonite and marmatite have similar surface properties. Separating them using a flotation method is inefficient. For separation of lead and zinc the lead mineral is generally floated preferentially to the zinc mineral, which appears in the sinks. In this study a new of collector, 2-aminothiophenol, is introduced that can float a zinc mineral, as a product entrapped in foam, preferentially. Single mineral flotation tests revealed that 2-aminothiophenol has good selectivity for flotation of marmatite. An artificial mixture of minerals used in a flotation test showed that 2-aminothiophenol can effectively separate marmatite from jamesonite. A product assaying at 45.06% Zn and 4.06% Pb was produced. FTIR spectra were employed to probe the adsorption mechanism of 2-aminothiophenol onto marmatite. The results indicate that adsorption of 2-aminothiophenol onto jamesonite and marmatite were, respectively, physical adsorption and chemical adsorption. This agrees with the flotation results.

Separation of feldspar from quartz: Mechanism of mixed cationic/anionic collector adsorption on minerals and flotation selectivity

Using pure albite and quartz minerals, the separation of albite from quartz using mixed cationic/anionic reagent schemes is assessed through Hallimond flotation, zeta potential and diffuse reflectance FTIR studies. The reagent schemes are tested in bench-scale flotation for the separation of albite from Greek Stefania feldspar ore. The single mineral flotation tests showed the feasibility of selective albite flotation from quartz at around pH 2 using a mixture of cationic diamine and anionic sulfonate collectors or a combined cationic-anionic collector of diamine-dioleate. In contrast to the selective flotation response of albite at pH 2, where albite is slightly negatively charged and quartz possess zero charge, the zeta potential and FTIR studies elucidate similar adsorption behavior of mixed collectors on both of the minerals. The infrared spectra not only showed the co-adsorption of anionic sulfonate or oleate with diamine on the surface but also showed that the diamine adsorption increases with the presence of anionic collector. The intrusion of anionic collector in between adjacent surface alkyl ammonium ions decreases electrostatic head-head repulsion, thereby increasing the diamine adsorption by increasing the hydrophobic tail-tail bonds. The discrepancy in the flotation and adsorption results at pH 2 is attributed to the coarse and fine size particles employed in these studies, respectively. The comparable adsorption on fine particles of albite and quartz at pH 2 is explained by the interaction of ammonium ions on silanol groups by hydrogen bonding besides electrostatic interactions. The bench-scale flotation results indeed showed that selective albite flotation takes place only after desliming the feed material. An albite concentrate exceeding 10%(by weight) Na 2 O is produced from a material containing about 6.5% (by weight) Na 2 O, where an albite product of more than 9% (by weight) Na 2 O is considered to be valuable.