Styrene Phosphonic Acid Research Articles

Unravelling the Flotation Performance of 1-Hydroxy-2-naphthyl hydroxamic Acid and Styrene Phosphonic Acid Collectors on Monazite Using Experiments and DFT Calculations.

The atomic-level structure and electronic properties of monazite were investigated using a first-principles method based on density functional theory (DFT). First, the geometric structure of monazite was optimized, followed by calculations of its Mulliken population, electron density, and density of states, which were subsequently analyzed. The findings of this analysis suggest that monazite is highly susceptible to cleavage along the {100} plane during crushing and grinding. When SPA was utilized as the collector, the recovery rate of monazite was higher than that when LF-P8 was used. The zeta potential and adsorption energy results indicated that the zeta potential after SPA adsorption tended towards negativity, and the adsorption energy was smaller, indicating that SPA exhibited stronger adsorption performance. LF-P8 was stably adsorbed on the monazite (100) surface via mononuclear double coordination. SPA was stably adsorbed on the surface of monazite (100) via binuclear double coordination. The results of this study provide valuable insights into the adsorption of monazite by commonly used flotation collectors. These findings are of substantial importance for future endeavors in designing flotation collectors capable of achieving selective monazite flotation.

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.

Molecular design of multiple ligand metal–organic framework (ML-MOF) collectors for efficient flotation separation of minerals

Metal–organic framework (MOF) collectors formed by the coordination of lead ions and benzohydroxamic acid (Pb–BHA) are favorably selective for the flotation separation of calcium-containing minerals. However, the large dosage requirement and foam instability have hindered the industrial applications of MOF collectors. To enhance the collecting ability and hydrophobicity of the Pb–BHA structure, this paper introduces new ligands to form multiple ligand–MOF (ML–MOF) collectors. Through a molecular-design approach, the study analyzes the crystal and electronic structures of the target and gangue minerals, calculates the quantum chemical properties of the organic ligands, constructs the ML–MOF collectors, and determines the interaction strengths between the ML–MOF collectors and mineral surfaces to predict the flotation performances. Finally, the flotation performance of the newly developed collector is confirmed through a series of micro-flotation tests. Among the ML–MOF collectors constructed with four candidate ligands—octylhydroxamic acid (OHA), sodium dodecyl sulfate (SDS), oleic acid, and styrene phosphonic acid—Pb–BHA–SDS and Pb–BHA–OHA excellently and selectively absorbed scheelite, wolframite, and cassiterite in flotation. In addition, they form stable froths and can be applied at low dosage. The correctness of the design results was quantified in terms of their collecting-ability index and selectivity index obtained in a flotation test. The proposed design methodology realizes ML–MOF collectors for the flotation separation of complex multi-mineral systems.

Adsorption mechanism of styryl phosphonate ester as collector in ilmenite flotation

A styryl phosphonate ester (SPE) collector was used to improve the flotation performance of ilmenite, and the adsorption mechanism and model were revealed and established, respectively. Microflotation tests showed that SPE exhibited a stronger collecting ability for ilmenite than the traditional collector styrene phosphonic acid (SPA). Zeta potential measurements revealed that both SPE and SPA could negatively shift the zeta potential of ilmenite, while SPE had more effects than SPA, suggesting the stronger adsorption of SPE. The analysis of X-ray photoelectron spectroscopy confirmed the chemisorption of SPA and SPE onto the Fe/Ti sites of ilmenite. According to frontier orbital theory, the chemical activities of SPE are greater than those of SPA. The partial densities of states analysis indicated that the PO—H groups of the collectors could interact with the Ti/Fe atoms of the ilmenite surface to generate a stable four-membered ring. The bonding model of the collector and (104) ilmenite surface showed that the adsorption energy of SPE was higher than that of SPA. Overall, SPE presented a better collecting ability and interaction effect for ilmenite flotation than SPA, and had the potential to replace SPA in the industry.

Investigations on the synergistic effect of combined NaOl/SPA collector in ilmenite flotation

Combined collector of different reagents is widely used in mineral flotation, while the synergistic effect mechanism remains in dispute. In this study, two anionic collectors of sodium oleate (NaOl) and styrene phosphonic acid (SPA) were applied in ilmenite flotation. Microflotation experiments showed that NaOl had a stronger collection ability than the SPA, and the mixed collector of NaOl and SPA at a molar ratio of 3:1 exhibited the best performance in ilmenite flotation. Zeta potential measurement revealed that both NaOl and SPA could adsorb onto the ilmenite surface. The practical zeta potentials of the ilmenite using a combined NaOl/SPA collector were different from the calculated value, suggesting the possible interaction between these two agents and the ilmenite surface. X-ray photoelectron spectroscopy (XPS) analysis revealed the chemical adsorption of NaOl at the Fe sites of the ilmenite surface while SPA could interact with both Fe and Ti sites at the ilmenite surface. Molecular dynamics simulation (MDS) showed that the adsorption energy improvement using a NaOl/SPA mixture could be attributed to the mutual complement of NaOl and SPA, in which NaOl were easier to generate compact adsorption structure and SPA had the ability to interact with more metal sites.

Flotation behavior and mechanism of hydroxycitric acid as a depressant on the flotation separation of cassiterite from calcite

In this study, the flotation separation of cassiterite (SnO2) from calcite (CaCO3) was investigated using hydroxycitric acid (HCA) which could effectively depress the flotation of calcite. Under the conditions of pH 8.0, styrene phosphonic acid (SPA) 80 mg/L, and HCA 6 mg/L, the flotation recovery of cassiterite and calcite was 82.01% and 19.18%, respectively, in the flotation experiments of single mineral, and a cassiterite concentrate with Sn grade of 62.24% and recovery of 85.60% was obtained in the flotation experiments of mixed artificial binary ore. The mechanism was also investigated by zeta potential measurements, Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses. The results illustrated that HCA selectively adsorbed on the calcite surface and could hinder the adsorption of SPA on calcite surfaces. However, SPA could still adsorb on cassiterite surface in the presence of HCA. Moreover, the results of FT-IR and zeta potential measurement indicated that there was specific adsorption between HCA and calcite, and XPS results revealed that HCA was adsorbed on the calcite surface through the interaction between the carboxyl groups of HCA and the Ca atom on the calcite surface. HCA could be used as a potential depressant in the flotation separation of cassiterite from calcite.

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.

Comprehensive investigation of the adsorption of 2-carboxyethylphenylphosphinic acid on cassiterite

ABSTRACT The structure–property relationship and adsorption mechanism of a novel collector for cassiterite, 2-carboxyethylphenylphosphinic acid (CEPPA), were comprehensively investigated and compared with those of styrene phosphonic acid (SPA) by density functional theory (DFT) calculations and flotation tests. The net Mulliken charge and frontier molecular orbital (FMO) theory study results indicated that CEPPA exhibited stronger electron-donating ability and higher chemical reactivity than SPA. The flotation test results demonstrated that CEPPA had stronger collecting ability for cassiterite in a much wider effective pH range than SPA. The adsorption simulation results confirmed that the CEPPA molecule was adsorbed on cassiterite (110) surface by two hydrogen bonds. CEPPA monoanion and dianion were adsorbed on cassiterite (110) surface by a series of O-Sn bonds, and the interactions between the O atoms in CEPPA phosphinic group with the Sn atoms on cassiterite (110) surface were stronger than those between the O atoms in CEPPA carboxyl group with the Sn atoms on cassiterite (110) surface. The formation of the O-Sn bonds was mainly contributed from the 2p orbital of O atoms and 5s and 5p orbitals of Sn atoms. The various adsorption configurations of CEPPA on cassiterite accounted for the better collecting ability of CEPPA for cassiterite than that of SPA. The quantitative analysis results were in good agreement with the qualitative experimental test results in a previous paper.

Effect and mechanism of Cu(II) on flotation separation of cassiterite from fluorite

The effect and mechanism of Cu(II) on the flotation separation of cassiterite from fluorite using styrene phosphonic acid (SPA) as a collector were investigated by flotation tests, zeta potential measurements, X-ray photoelectron spectroscopy (XPS) analysis and density function theory (DFT) calculations. SPA showed good collecting ability for both cassiterite and fluorite, and Cu(II) could intensively and selectively depress fluorite. At pH 4.0, using 100 mg/L SPA as the collector and 5 × 10−4 mol/L Cu(II) as the inhibitor, a tin concentrate with a grade of 92.3% SnO2 and a recovery of 85.6% was obtained for an artificially mixed sample which contained 47.86% SnO2. Zeta potential and XPS analyses indicated that Cu(II) was anchored on cassiterite surface but not on fluorite surface, and Cu(II) hindered the adsorption of SPA on fluorite but had negligible influence on the adsorption of SPA cassiterite. DFT calculations confirmed that the affinity between Cu(II) and SPA is much stronger than that between Cu(II) and fluorite surface, and the adsorption of SPA on cassiterite surface was not weakened by the presence of Cu(II). Consequently, it was inferred that Cu(II) consumed the collector SPA in the pulp, and the flotation of cassiterite was unaffected but fluorite was depressed by Cu(II). Therefore, Cu(II) is an effective inhibitor for the flotation separation of cassiterite from fluorite.

A novel surfactant styryl phosphonate mono-iso-octyl ester with improved adsorption capacity and hydrophobicity for cassiterite flotation

In this paper, a novel surfactant styryl phosphonate mono-iso-octyl ester (SPE108) was introduced as a collector for the flotation of cassiterite for the first time. Structure-reactivity relationship of SPE108 was predicted by density functional theory (DFT) calculation, which indicated that the reactive sites of SPE108 mainly located on the PO and OH groups. Meanwhile, DFT calculations also elucidated that SPE108 possess stronger electron-donating ability to minerals than traditional collectors styrene phosphonic acid (SPA) and benzohydroxamic acid (BHA). The micro-flotation tests showed that SPE108 exhibited better collecting ability in the flotation of cassiterite compared with SPA and BHA. Adsorption tests inferred that SPE108 could adsorb onto cassiterite surface more easily than SPA and BHA. Surface tension and contact angle measurements indicated that the hydrophobization intensity of these collectors toward cassiterite was in the order as SPE108 > SPA > BHA. FTIR and XPS analyses indicated that SPE108 interacted with cassiterite mainly through the breakage of POH bond with the formation of POSn bond. Finally, the bonding model of SPE108 with cassiterite was proposed.

In Situ Investigation of the Adsorption of Styrene Phosphonic Acid on Cassiterite (110) Surface by Molecular Modeling

Abstract: The flotation, adsorption and bonding mechanisms of styrene phosphonic acid (SPA) to cassiterite were studied using microflotation tests, zeta potential measurements, solution chemistry analysis and density functional theory (DFT) calculations in this paper. Flotation results demonstrated SPA was an excellent collector for cassiterite which could recover over 85% cassiterite particles with the pH range 4.3–6.06 and 40 mg/L SPA. Zeta potential measurements and solution chemistry analysis revealed the adsorption of SPA was mainly contributed by the chemisorption of the monoanions on cassiterite surfaces. Frontier molecular orbital theory analysis and adsorption energy calculation results proved the monoanion of SPA was able to replace the OH− on cassiterite surfaces. The adsorption structure optimization results confirmed the binuclear complex was the most favorable adsorption configuration of SPA on cassiterite (110) surface. Mulliken population calculations and density of states analysis indicated during the bonding process the Sn3 atom lost electrons to O3 atom, and the bonding interaction between O3 and Sn3 atoms was mainly from the contribution of the 2p orbital of O3 atom and the 5s and 5p orbitals of Sn3 atom.

Flotation performance and adsorption mechanism of styrene phosphonic acid as a collector to synthetic (Ce,La)2O3

The flotation performances of styrene phosphonic acid (SPA) to synthetic (Ce,La)2O3 (REO), calcium fluorite (CaF2) and fluorapatite (Ca5F(PO4)3) were investigated by flotation tests, flotation of synthetic mixed mineral, the surface adsorption capacity and the polarizing microscopy to solve the flotation separation problem of rare earth oxides from roasted concentrate. The flotation test results indicated that compared with CaF2 and Ca5F(PO4)3, SPA exhibited superior collecting performance to direct flotation recovery of REO and floated out above 90% REO at pH 3–6. However, the collecting ability of SPA to CaF2 and Ca5F(PO4)3 was extremely weak and the highest recovery was only 20% at pH 2–11. The flotation of synthetic mixed mineral showed that SPA was a good collector reagent for flotation of synthetic REO at pH 5, so REO, CaF2 and Ca5F(PO4)3 could be separated from roasted concentrate by using SPA as a collector. The surface adsorption capacity tests and polarizing microscopy results confirmed that SPA was adsorbed on REO surface, while CaF2 and Ca5F(PO4)3 were not. The adsorption mechanism of SPA to synthetic REO was studied by solution chemistry analysis of collector, the ζ-potential tests, infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. The results indicated that SPA was physically adsorbed onto REO surface, which exhibited excellent flotation selectivity to REO against CaF2 and Ca5F(PO4)3.

Flotation behavior and adsorption mechanism of (1-hydroxy-2-methyl-2-octenyl) phosphonic acid to cassiterite

The flotation behavior and adsorption mechanism of novel (1-hydroxy-2-methyl-2-octenyl) phosphonic acid (HEPA) to cassiterite were investigated by micro-flotation tests, zeta potential measurements, FTIR determination and density functional theory (DFT) calculation. The flotation results demonstrated that HEPA exhibited superior collecting performance compared with styrene phosphonic acid (SPA). The cassiterite recovery maintained above 90% over a wide pH range of 2–9 with 50 mg/L HEPA. The results of zeta potential measurement and FTIR detection indicated that the adsorption of HEPA onto cassiterite was mainly attributed to the chemisorption between HEPA monoanions and Sn species on mineral surfaces. The DFT calculation results demonstrated that HEPA monoanions owned higher HOMO energy and exhibited a better affinity to cassiterite than SPA, which provided very clear evidence for the stronger collecting power of HEPA presented in floatation test and zeta potential measurement.

Flotation performances and adsorption mechanism of α-hydroxyoctyl phosphinic acid to cassiterite

In this paper, the flotation performances and adsorption mechanism of α-hydroxyoctyl phosphinic acid (HPA) to cassiterite were investigated by adsorption experiments, micro-flotation tests, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The micro-flotation results indicated that compared with styrene phosphonic acid (SPA), diphosphonic acid (DPA), benzohydroxamic acid (BHA) and salicylhydroxamic acid (SHA), HPA exhibited excellent collecting power to cassiterite and superior selectivity against magnetite or hematite over a wide pH range. The results of adsorption experiments and zeta potential deduced that HPA chemisorb on cassiterite surfaces. The results of FTIR inferred HPA chemisorb onto cassiterite surfaces through its P and O atoms with the P–H and O–H bonds broken. XPS analysis further demonstrated HPA react with Sn species by formation of Sn–O–P and Sn–P bond.

Flotation behavior and adsorption mechanism of α-hydroxyoctyl phosphinic acid to malachite

The flotation behavior and adsorption mechanism of α-hydroxyoctyl phosphinic acid (HPA) to malachite were investigated by micro-flotation tests, zeta potential measurements, and FTIR and XPS analysis. The micro-flotation results demonstrated that compared with sodium isobutyl xanthate (SIBX) and styrene phosphonic acid (SPA), HPA exhibited superior collecting performances to direct flotation recovery of malachite and floated out above 80% malachite at pH 5–10. The results of zeta potential measurement inferred that there might be covalent bonds between HPA and copper on the malachite surface. The FTIR analysis confirm that HPA might react with copper species of malachite surfaces to form Cu–HPA complex adsorption layers, with a release of H+ ions (from PH group). The XPS analysis provided very clear evidence that the Cu(II) species was partly reduced to Cu (I) species during HPA chemisorption on malachite surfaces, accompanying P(III) oxidation to P(V) species of HPA.

Studies on styrene phosphonic acid

Some properties of styrene phosphonic acid (SPA) were studied. The crystals were triclinic, witha=0.6434 nm,b=0.5842 nm,c=2.0338 nm, α=96.17°, β=97.33°, γ=79.65° andZ=4. SPA underwent a change in crystal structure at 78.8°C, the hydrocarbon network became disordered (“liquid-like”) at 138.5°C. Crystals melted at 148.6°C giving a cubic mesophase, then changed to an isotropic liquid at 155.6°C and at 162.13°C SPA underwent decomposition. Values for pK1=2.15 and pK2=7.66 were obtained at 25°C. The water solubility of SPA at several temperatures, and its interaction with surfactant micelles were determined.

Evaluation of mitomycin-treated vero cells as a coculture system supportive of the in vitro development of IVM/IVF-derived bovine zygotes to hatched blastocysts

Styrene phosphonic acid (SPA) is one of the best collector reagents for flotation of cassiterite and the best collector for the flotation of finely disseminated cassiterite and wolframite ores. Data from our research work has shown that only with SPA is it possible to obtain higher grade tin concentrates containing more than 40% Sn at high recoveries.The basis for this is the named collector, a highly developed reagent system and a special flotation technology, which was carried out in cyclic Laboratory tests with tin ores from Czechoslovakia, Canada, Portugal and Germany, and introduced into the processing plants at Neves Corvo, Portugal, Rio Kemptville, Canada and Altenberg, Germany.

Cassiterite flotation using styrene phosphonic acid to produce high-grade concentrates at high recoveries from finely disseminated ores- comparison with other collectors and discussion of effective circuit configurations

Styrene phosphonic acid (SPA) is one of the best collector reagents for flotation of cassiterite and the best collector for the flotation of finely disseminated cassiterite and wolframite ores. Data from our research work has shown that only with SPA is it possible to obtain higher grade tin concentrates containing more than 40% Sn at high recoveries. The basis for this is the named collector, a highly developed reagent system and a special flotation technology, which was carried out in cyclic Laboratory tests with tin ores from Czechoslovakia, Canada, Portugal and Germany, and introduced into the processing plants at Neves Corvo, Portugal, Rio Kemptville, Canada and Altenberg, Germany.

中国レアメタルの浮選に関する研究

Using nonylxanthate, A.R.845, sodium dodecyl sulfate, styrenephosphonic acid and hydroxamate for collectors, flotation of tin ore which contained Ta, Nb and W was investigated after grinding of the ore under 400 mesh. Suspensions of the sample for flotation were buffered at a pH around 8 because of the large amount existence of Ca carbonate minerals in the ore, therefor, most of flotation experiments were carried out at natural pH. In this condition A.R.845 and styrenephosphonic acid were more effective to Ca minerals than rare metal minerals, while hydroxamate was a effective collector to rare metal minerals. 88 wt%S was removed and 94 wt%Sn, 96 wt%Ta, W and 97 wt%Nb were recovered from the sample by use of nonylxanthate. By use of sodium dodecyl sulfate, 98 wt%Ca was removed and 85 wt%Sn, 91 wt%Ta and 72 wt%Nb were recovered from the sample.

Design and application of a liquid-flow adsorption micro calorimeter based on the Calvet-type DAK 1-1 microcalorimeter (USSR)

The construction and the properties of a liquid-flow adsorption microcalorimeter are described. The calorimeter is based on the commercially available Calvet-type DAK 1-1 microcalorimeter (USSR), which has been equipped with a flow system consisting of a pump, several sets of heat exchangers and an adsorption cell. The minimum detectable heat effect is 1μW up to a flow rate of 30 cm3/h. Results on the application of the calorimeter to adsorption and desorption processes of nonionic (Triton X-100) and anionic (styrene phosphonic acid) surfactant solutions in water at anα-Al2O3 surface are presented and discussed.