Flotation Separation Of Fluorite Research Articles

The inhibition mechanism of esterified starch on flotation separation of fluorite and calcite

Herein, the flotation behavior of fluorite and calcite was examined before and after starch esterification through mineral flotation experiments. Moreover, the adsorption action mechanisms on minerals before and after starch esterification were investigated using methods such as solution surface tension measurement, infrared spectroscopy, and extended Derjaguin–Landau–Verwey–Overbeek theory. The results showed that after starch esterification (esterified starch), there was a greater difference in the mineral recovery rate compared to before starch esterification (ordinary starch), with a better inhibition effect on calcite. The interaction between mineral surfaces and ordinary starch was weaker than the interaction between minerals and esterified starch. In particular, after starch esterification, the surface tension increased, two minerals contact angle decreased, the surface potential became more negative, and the difference in the mineral recovery rate was greater than before starch esterification. After the interaction between minerals and esterified starch, calcite particles displayed good dispersibility, while the cohesion between calcite particles and sodium oleate particles decreased; notably, the effect on fluorite was opposite. Calcite and esterified starch exhibited chemical adsorption, impeding the adsorption of sodium oleate onto calcite and resulting in calcite inhibition. The interaction between fluorite surface and esterified starch involved electrostatic adsorption, with sodium oleate chemically adsorbed onto the fluorite surface. Chemical adsorption proved stronger than electrostatic adsorption, enabling sodium oleate to capture fluorite.

Microscopic perspective of the combined collector CTAB/SPA on the flotation separation of fluorite and calcite: Adsorption morphology and interaction force

It is difficult to separate fluorite and calcite due to their similar surface properties. This article applied combined collector cetyltrimethylammonium bromide (CTAB)/styrene phosphonic acid (SPA) to separate fluorite from calcite and explored the adsorption morphology and interaction force. Flotation results indicated that effective separation between fluorite and calcite with CTAB/SPA at a molar ratio of 1:1, at the concentration of 1×10−4 mol/L and pH 11.0. Surface tension measurements indicated a synergistic effect of CTAB/SPA in solution. The combined collector increased the hydrophobicity difference between fluorite and calcite surfaces. Zeta potential measurements illustrated that both CTAB and SPA adsorbed on fluorite and calcite surfaces, with CTAB as the main collector. Atomic force microscope (AFM) analysis further demonstrated that more CTAB/SPA adsorbed on fluorite surface than that on the calcite surface, resulting in a stronger hydrophobic force between fluorite particles. It was concluded that CTAB, as the main collector in the combined collector, adsorbed on the fluorite surface, while SPA interspersed between the CTAB molecules, with an adsorption model proposed. These macroscopic and microscopic points provide a possibility for the flotation separation between fluorite and calcite.

The exploration of tannin extract as a green depressant in the flotation separation of fluorite from calcite

In response to the flotation separation issue of fluorite and calcite, the utilization of tannin extract (TE) as a depressant for the feasibility of two minerals separation was studied in this study. Microflotation results revealed that the high floatability of fluorite and calcite was obtained using the sodium oleate (NaOl) as the collector, and the addition of TE could completely depress the calcite flotation while it had small effects on the fluorite flotation. The flotation of artificial mixed fluorite/calcite confirmed that TE had the efficient and selective depressing ability to achieve effective separation performance. The adsorption measurements showed that the adsorption amount of TE on the calcite surface was much higher than that on the fluorite surface. Zeta potential results indicated that NaOl could be adsorbed on the fluorite surface but not on the calcite surface in the presence of TE. X-ray photoelectron spectroscopy illustrated that TE only chemisorbed onto the calcite surface but weakly interact with the fluorite surface. The computational chemistry analysis revealed that the adsorption energy of TE onto the calcite surface was much lower than that onto the fluorite surface. A stable four-member chelating compound was only generated by the chemical interaction between TE and calcite. Thus, TE can act as the potential depressant in the flotation separation of fluorite from calcite.

Flotation separation of fluorite and calcite using anhydrous glucose and aluminum sulfate as a combined depressant

The effective flotation separation of fluorite and calcite is a critical problem in the mineral processing industry owing to their similar physicochemical characteristics. In this study, the effect of glucose (Glu) and Al3+ on the flotation separation of fluorite and calcite was studied using micro-flotation experiments, scanning electron microscopy (SEM), solution chemistry calculation, X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The micro-flotation experiments demonstrate that the combination of Glu and Al3+ had a significant depression effect on calcite. However, it slightly affected fluorite flotation. The SEM results indicate that Glu and Al3+ had a greater tendency of absorption on the calcite surface than that of fluorite. The solution chemistry calculation and XPS analysis exhibit that the increased selective depression of Glu on calcite with the addition of Al3+ was due to the formation of Al (OH) 3 and Al2O3 on the calcite surface. The DFT results exhibit that Ca-O bonds were formed when Glu interacted with fluorite. Additionally, Ca-O, C–H, and H-O bonds were formed when Glu interacted with the surface of calcite. The surface bonding characteristics of Glu with fluorite and calcite led to a difference in the adsorption energy. The glucose and Al2O3 glucose formed on the surface of calcite improved the adsorption through Al-O bond, which increased the adsorption sites on the surface of calcite and enhanced the depression effect of Glu on calcite.

Flotation separation of fluorite from calcite by a new depressant curdlan and its mechanism

Flotation separation of fluorite from calcite by a new depressant curdlan and its mechanism

Selective Adsorption of Sodium Silicate on the Surface of Bastnaesite and Fluorite in Salicylhydroxamic Acid System under Alkaline Conditions

During the flotation separation process of bastnaesite, it is difficult to separate bastnaesite from fluorite effectively. In this present study, sodium silicate (SS) can effectively improve the flotation separation effect of bastnaesite and fluorite in salicylhydroxamic acid (SHA) systemasa. Through relevant analyses, such as Zeta potential measurements, adsorption capacity tests, Fourier transform infrared (FTIR) spectroscopic analyses and X-ray photoelectron spectroscopy (XPS) tests, the selective suppressor of SS on fluorite was proven. At pH 10, the single mineral flotation results show that with the increase of SS dosage, the flotation recovery of fluorite rapidly decreases from 61.5% to 35.31%, while the flotation rate of bastnaesite is still high (recovery is 80.02%). Then, the experiment of artificial mixed ore proved that the flotation separation of fluorite and bastnaesite was effective under the appropriate dosage of inhibitor. The results of potentiodynamic measurement and an adsorption capacity test showed that the SiOOH3− structure of SS more easily reacted with fluorite, which further prevented the adsorption of SHA on the fluorite surface. FTIR test results and XPS analysis further showed that SS had a strong binding effect with the Ca site on the fluorite surface, but a weak binding effect with the Ce site on the bastnaesite surface. Consequently, SS can be used as an effective inhibitor in the flotation separation of fluorite and bastnaesite.

Evaluation of 2-phosphatebutane-1, 2, 4-tricarboxylic acid as a depressant in the flotation separation of fluorite from barite

It is hard to separate barite from fluorite due to their similar surface properties. In this work, to achieve the separation of barite from fluorite, 2-phosphatebutane-1, 2, 4-tricarboxylic acid (PBTCA) was used to depress fluorite, and the floatability, separation efficiency and mechanism were researched by micro-flotation tests, zeta potential measurements, solution chemistry calculation and XPS analysis. Micro-flotation results showed that sodium dodecyl sulfonate (SDS) had an extremely good collecting capability for fluorite and barite, while PBTCA selectively depressed the floatability of fluorite and then allowed the recovery of barite. The flotation tests of artificial mineral mixtures showed that barite and fluorite can be effectively separated using PBTCA/SDS in a reasonable way. The zeta potential results indicated that PBTCA hindered the interaction of SDS with fluorite surface while had no influence on that for barite. The XPS analysis indicated that chemical interaction occurred between PBTCA and fluorite surface. Hence, it can be inferred PBTCA could be utilized as a promising depressant for the separation of fluorite from barite.

Difficulties and Recent Achievements in Flotation Separation of Fluorite from Calcite—An Overview

As an important strategic non-metallic mineral resource, fluorite has been widely used in various industrial fields, such as metallurgy, optics and semiconductor manufacturing, as well as fluorine-related chemical engineering. Since the major gangue minerals of fluorite ore are silicate and carbonate ones, flotation is the main beneficiation method for the concentration. Compared with the relatively easy operation for silicate-type fluorite ore, fluorite concentration from calcite has always been the most difficult challenge in the field of mineral processing. In this review, analyses of the fundamental reasons for the difficulties of flotation separation of fluorite from calcite are performed, from the similar surface properties of both calcium minerals to the deterioration by the interference of dissolved ions in the pulp during grinding and flotation. Recent achievements in the flotation separation of fluorite from calcite as the main contents are comprehensively summarized, covering all aspects of flotation reagents of collectors, depressants and modifiers. Finally, successful examples of industrial practices for fluorite and calcite flotation separation are introduced. This overview provides a detailed and comprehensive reference source for the current research status of fluorite and calcite flotation separation, and some suggestions for future research are provided.

Selective Separation of Fluorite from Scheelite Using N-Decanoylsarcosine Sodium as a Novel Collector

Fluorite and scheelite, which are strategic calcium-bearing minerals, have similar active sites (Ca2+); as a result, the efficient separation of the two minerals is still one of the world’s most difficult problems in the field of flotation. In this work, N-decanoylsarcosine sodium (SDAA), a non-toxic and low-cost amino acid surfactant, was applied in the flotation separation of fluorite from scheelite for the first time. In the test, single mineral, binary mixed minerals, and actual ore experiments showed that the pre-removal of fluorite from scheelite by reverse flotation can be achieved. The results of adsorption capacity detections, zeta potential tests, and FTIR analysis showed that the negatively charged SDAA prefers to adsorb onto the positively charged fluorite surface due to the electrostatic interaction. The results of crystal chemistry and DFT calculations showed that SDAA has a stronger chemical interaction and more electron transfer numbers to the Ca atom on the fluorite surface and forms a Ca-SDAA complex. Therefore, the significant difference in the adsorption behavior of SDAA on the surfaces of two minerals provided a new insight into the separation efficiency of amino acids and possesses a great potential for industrial application in scheelite flotation.

Utilization of gellan gum as a novel eco-friendly depressant in the flotation separation of fluorite from barite

The relatively similar physicochemical features and floatabilities of fluorite and barite in the flotation process make the separation of these two minerals rather difficult. Exploration and utilization of efficient depressants is vital to improve the flotation separation performance. In this study, gellan gum (GG) was adopted as the depressant in the flotation separation of fluorite and barite with sodium oleate (NaOL) as collector for the first time. The inhibitory impact of gellan gum on the flotation performances of these two minerals was evaluated via flotation tests. The potential inhibiting mechanism of GG was systematically revealed via series of surface analytical measurements. Flotation experiments indicated that GG exhibited strong depressing effect on the barite flotation, whilst it showed little impact on the fluorite flotation. Zeta potential tests and surface wettability analyses demonstrated that GG intensely adhered onto barite and strongly prevented the subsequent NaOL adsorption, while it barely affected the NaOL adsorption onto fluorite. Adsorption capacity measurements confirmed that much higher amount of GG adsorbed onto barite than fluorite. Fourier transform infrared (FTIR) spectroscopy analyses and X-ray photoelectron spectroscopy (XPS) results implied that the quite weak physisorption of GG on the fluorite surface occurred, whereas strong chemical adhesion of GG occurred between GG and barite, which resulted in completely disparate flotation behaviors of these two minerals. As a result, selectively depression of barite flotation and the flotation separation of fluorite from barite were achieved. Therefore, GG can be used as an efficient and eco-friendly depressant to realize the flotation separation of fluorite and barite.

New insights into the role of calcium dioleate in selectively separating fluorite from calcite during cleaning process

Research on fluorite and calcite cleaning process have been ignoring the effects of calcium dioleate in pulp on flotation. In this study, flotation tests showed that flotation separation of fluorite and calcite could be achieved by the cleaning process under acidic conditions. Solution chemistry equilibrium calculations revealed that large amounts of calcium dioleate formed, and this compound was the main component in the cleaning solutions of fluorite and calcite under acidic conditions. Desorption and adsorption tests, contact angle measurements and atomic force microscopy (AFM) revealed the mechanism of selective separation of fluorite and calcite during the cleaning process under acidic conditions. Flotation tests showed that under acidic conditions, calcite flotation was strongly inhibited but fluorite flotation was less affected. Desorption and adsorption measurements and mineral surface contact angle analysis revealed that under acidic conditions, the calcium dioleate on the surface of calcite rough concentrate was desorbed into the solution, whereas the calcium dioleate in the solution did not readily absorb on calcite surface. The calcium dioleate on the surface of fluorite rough concentrate was hardly desorbed, whereas the calcium dioleate in the solution continued to adsorb on the surface. AFM intuitively confirmed the desorption of calcium dioleate from calcite surface and the adsorption of this compound on fluorite surface under acidic conditions. The selective adsorption of calcium dioleate on fluorite rough concentrate is an important factor that promotes the selective separation of fluorite and calcite during the cleaning process.

The role of copper ion and soluble starch used as a combined depressant in the flotation separation of fluorite from calcite: New insights on the application of modified starch in mineral processing

• Cu 2+ and soluble starch (SS) together enhance fluorite/calcite flotation separation. • The mechanism was systematically studied from chemical and atomic perspectives. • Cu SS complex interacts strongly with calcite but only weakly with fluorite . • Metal-ion modified starches are flotation reagents with great potential. The flotation separation of fluorite and calcite poses a long-standing challenge in the mineral processing industry because of their similar physicochemical characteristics. In this study, the effects of Cu 2+ and soluble starch (SS) in the separation of fluorite from calcite by flotation, and the mechanisms behind these effects, were investigated using micro-flotation experiments, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), time of flight secondary ion mass spectrometry (ToF-SIMS) and density functional theory (DFT). The micro-flotation experiments show that the combination of Cu 2+ and SS exhibits a stronger selective depression effect on calcite than that produced by SS alone; in contrast, the effect on fluorite flotation is relatively small. The XPS, FT-IR and ToF-SIMS analyses show that Cu 2+ can react with SS to form a Cu SS complex, which has better selectivity, resulting in the difference in flotation performance between fluorite and calcite. DFT results show that the SS and the Cu-SS complex form different chemical bonds during their interactions with the mineral surfaces: Ca O bond and H F bonds are formed when SS interacts with the fluorite surface, and Ca O and hydrogen bonds are formed when SS interacts with the calcite surface. A Ca Cu bond is formed when the Cu SS complex interacts with the fluorite surface, but both Cu O and Ca Cu bonds are formed when the Cu SS complex interacts with the calcite surface. This causes differences in adsorption energy. The adsorption energies of the interactions between SS or Cu SS complex and the surfaces of fluorite and calcite are ranked as: calcite + Cu SS complex > calcite + SS > fluorite + SS > fluorite + Cu SS complex.

Effect and mechanism of depressant CK102 on flotation separation of fluorite and dolomite

Effect and mechanism of depressant CK102 on flotation separation of fluorite and dolomite

Pb-water glass as a depressant in the flotation separation of fluorite from calcite

The flotation separation of fluorite and calcite poses a long-standing challenge in the mineral processing industry because of their similar physicochemical characteristics. This study uses sodium oleate (NaOL) as the collector and Pb-water glass as the depressant to improve the fluorite-calcite separation efficiency. The effect of Pb-water glass was analyzed using micro-flotation experiments, calculations of solution chemistry, X-ray photoelectron spectroscopy (XPS), zeta potential and time of flight secondary ion mass spectrometry (ToF-SIMS). The results of micro-flotation experiments show that Pb-water glass exhibits a stronger selective depression effect on calcite than water glass alone, but is considerably less sensitive to fluorite flotation. The calculations of solution chemistry, XPS and zeta potential results show that the improved depression effect can be attributed to lead ions, which not only increase the adsorption of silicate species on the calcite surface but also improve the formation of Pb-silicate polymer species. The ToF-SIMS results further show that the adsorption of Pb-water glass on the calcite surface interferes with the adsorption of NaOL on the calcite surface, thereby reducing the floatability of calcite. • Fluorite is difficult to separate from calcite using only a water glass depressant. • Pb(NO 3 ) 2 enhances the selective depression effect of water glass on calcite. • The adsorption mechanism of Pb-water glass on the mineral surface is discussed.

Effect of Artemisia sphaerocephala Krasch. Gum on the flotation separation of fluorite from calcite

The effect of Artemisia sphaerocephala Krasch. gum (ASKG) on the flotation separation of fluorite and calcite with sodium oleate (NaOl) as collector was studied for the first time. Results of micro-flotation and artificial mixed mineral experiments proved that ASKG had a strong depression effect on calcite, but the flotation of fluorite was barely effected by ASKG within the pH range studied. Zeta potential analysis results confirmed an evident adsorption difference of ASKG, and the adsorption strength of ASKG on calcite was much stronger than that of fluorite. The results of Fourier-transform infrared spectroscopy analysis suggested that ASKG hardly affected the chemical interaction between NaOl and fluorite, but the pre-adsorption of ASKG on calcite surface could further prevent the adsorption of NaOl. Meanwhile, X-ray photoelectron spectroscopy analysis results indicated that ASKG could be adsorbed on calcite surface to improve the hydrophilicity by the strong complexation of hydroxyl (–OH) with Ca2+. Therefore, the flotation separation of fluorite and calcite could be realized due to the remarkable difference of NaOl adsorption by using ASKG as selective depressant.

Haldor Topsoe and Yanchang form joint venture and build methanol catalyst facility in China

The flotation separation of fluorite and calcite poses a long-standing challenge in the mineral processing industry because of their similar physicochemical characteristics. This study uses sodium oleate (NaOL) as the collector and Pb-water glass as the depressant to improve the fluorite-calcite separation efficiency. The effect of Pb-water glass was analyzed using micro-flotation experiments, calculations of solution chemistry, X-ray photoelectron spectroscopy (XPS), zeta potential and time of flight secondary ion mass spectrometry (ToF-SIMS). The results of micro-flotation experiments show that Pb-water glass exhibits a stronger selective depression effect on calcite than water glass alone, but is considerably less sensitive to fluorite flotation. The calculations of solution chemistry, XPS and zeta potential results show that the improved depression effect can be attributed to lead ions, which not only increase the adsorption of silicate species on the calcite surface but also improve the formation of Pb-silicate polymer species. The ToF-SIMS results further show that the adsorption of Pb-water glass on the calcite surface interferes with the adsorption of NaOL on the calcite surface, thereby reducing the floatability of calcite.

Investigation on the flotation separation of fluorite from celestite using a novel depressant: Sodium polynaphthalene formaldehyde sulfonate

Sulfate minerals have gradually become the main gangue minerals of fluorite deposits, and the flotation separation of fluorite and sulfate minerals is difficult with commonly used depressants. In this paper, the high selectivity of a novel depressant sodium polynaphthalene formaldehyde sulfonate (SPS) for the flotation separation of fluorite and celestite both in single mineral and artificial mixed ore experiments was studied, and the underlying separation mechanism was investigated by zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) analysis, and Atomic force microscopy (AFM) imaging analysis. Flotation results showed that, in the presence of sodium oleate (NaOL) and SPS, the flotation recovery difference between fluorite and celestite reached 76.26% and the grade of fluorite concentrates increased by 32.11% at pH 6.0. The analysis results showed that the adsorption of SPS on the fluorite surface was limited at pH 6.0, and the adsorption was most likely be through electrostatic interaction. For celestite, the adsorption of SPS on the surface significantly changed the chemical surrounding of celestite surface inhibiting the chemical adsorption of NaOL, and the chemical adsorption of SPS was more significant at pH 6.0.

The flotation separation of fluorite from calcite using hydroxypropyl starch as a depressant

The effect of hydroxypropyl starch (HPS) on the flotation separation of fluorite from calcite using sodium oleate (NaOl) as a collector was studied. Micro-flotation results of single minerals showed that both fluorite and calcite presented good floatability in the presence of NaOl. However, by adding HPS before NaOl, the calcite flotation recovery was selectively reduced. The flotation of artificially mixed minerals confirmed that an efficient separation of fluorite from calcite could be achieved using the reagents scheme of HPS/NaOl. Zeta potential measurements demonstrated that HPS prevented the NaOl adsorption onto the calcite surface while it did not inhibit the interaction of NaOl with the fluorite surface. Fourier Transform Infrared (FT-IR) analysis was also revealed that the selective adsorption of HPS onto the calcite surface.

Flotation behavior and mechanism of styrene phosphonic acid as collector on the flotation separation of fluorite from calcite

SPA was selected as the collector to separate fluorite from calcite. The greatest difference of recovery of fluorite and calcite was achieved with SPA dosage of 20 mg/L and pH 6.0, at which the recovery of fluorite and calcite was 98.79% and 12.55% respectively. The AFM 3D images of fluorite and calcite in the absence and presence of SPA revealed that the amount of SPA adsorbed on fluorite was much more than that on calcite, which accounted for the difference of flotation recovery. The flotation adsorption mechanism of SPA on fluorite was further explored by FT-IR, zeta potential measurements, XPS and first-principles calculation. It was found that SPA was adsorbed on fluorite surface by chemical interaction, and the calcium atom on fluorite was the main active site to react with SPA. The species distribution diagram of SPA in different pH revealed that when pH was 6, the main species of SPA were monovalent ion (C8H7PO3H−) and divalent ion (C8H7PO32−). Thus, there were three possible adsorption models for SPA to be adsorbed on fluorite surface, including coordination between single oxygen and single calcium, coordination between double oxygen and single calcium, and coordination between double oxygen and double calcium. The first-principles calculation demonstrated that among these three possible adsorption models, the adsorption model of coordination between single oxygen and single calcium was the most possible adsorption model.

Mechanism of phthalic acid collector in flotation separation of fluorite and rare earth

The mechanism of phthalic acid, a dicarboxylic acid collector, in flotation separation of fluorite and rare earth (RE) was studied in this paper. The experimental data of flotation show that phthalic acid, as the collector, can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions. The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement, the Fourier transform infrared (FT-IR), the X-ray photoelectron spectroscopy (XPS) and the stability constant measurement of active metal ion and phthalic acid coordination complex. According to the zeta potential testing results, the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which, in turn, increases its electronegativity and results in the motion of its potential. After the reaction between phthalic acid and fluorite ores under weakly acidic conditions, the peak of the fluorite ores is found to have significant changes in the FT-IR results, indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores. According to the XPS analysis, the peak of benzene ring of phthalic acid is as high as 2% on the surface of fluorite, while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite. According to the pH potentiometric titration results, the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant Ktotal' of cerium phthalate complex, indicating that the complex generated between phthalic acid and Ca2+ is more stable than the complex generated between phthalic acid and Ce3+. The possible reason is that Ca2+, with the highest reticular density, plays a prevailing role in the octahedron structure of fluorite amidst the acidic media. As the active point of flotation, Ca2+ works with the carboxyl groups of the collector phthalic acid (–C=O–) to form polycyclic calcium phthalate complex.