Octyl Hydroxamic Acid Research Articles

Flotation performance and adsorption mechanism of monazite after the transformation of hydrogen-based mineral phase by octyl hydroxamic acid

Flotation performance and adsorption mechanism of monazite after the transformation of hydrogen-based mineral phase by octyl hydroxamic acid

Experimental and theoretical computational study of corrosion inhibitors in the cobalt bulk chemical mechanical polishing (CMP) process

Cobalt is a potential substitute for copper as local interconnects in sub-10 nm interconnects, the chemical mechanical polishing (CMP) of which is quite challenging due to the high chemical reactivity of Co. By using a combination of experiments and theoretical calculations, the optimum corrosion inhibitor of Co is identified and the corrosion inhibition mechanism of TTLYK on Co is further investigated. It investigates the effects of various corrosion inhibitors, including potassium oleate, dodecyl benzene sulphonic acid, octyl hydroxamic acid, and 2,2′-[[(methyl-1H-benzotriazol-1yl) methyl] imino] bis-ethanol (TTLYK) on Co through chemical mechanical polishing and static etching experiments. The results show that among various corrosion inhibitors, TTLYK presents the best corrosion inhibition effect. When the basic slurry contains 10 mM TTLYK, the corrosion inhibition efficiency could reach 96.23 %, the material removal rates of Co is 161.79 nm/min, the static etching rates is 0.85 nm/min, and the material removal selectivity ratio of Co and Ti is 39:1. The results fully meet the requirements of the Co bulk CMP process. It is revealed TTLYK could form a protective layer with a synergistic physical and chemical adsorption on Co, in which the chemical adsorption occurs through the formation of CoN bonds. The adsorption of TTLYK could decelerate the transformation of CoO and Co(OH)2 to Co3O4, and the as formed Co-TTLYK complex provides the main corrosion inhibition.

New Insights into the Depressive Mechanism of Sodium Silicate on Bastnaesite, Parisite, and Fluorite: Experimental and DFT Study

The surface properties of bastnaesite and parisite are similar to their associated gangue mineral, fluorite, which makes the flotation separation of these two rare earth minerals from fluorite one of the industry’s most significant challenges. This study systematically investigates the inhibitory effects and mechanisms of sodium silicate (SS) on bastnaesite, parisite, and fluorite in an octyl hydroxamic acid (OHA) collector system through flotation experiments, various modern analytical methods, and DFT simulations. The flotation test results indicate that the inhibition effects of SS on the three minerals are in the order: fluorite > parisite > bastnaesite. Detection and analysis results indicate that SS forms hydrophilic complexes with Ca atoms on the surfaces of fluorite and parisite, enhancing surface hydrophilicity and inhibiting OHA adsorption, but its impact on bastnaesite is relatively minor. DFT simulation results show that OHA forms covalent bonds with metal ions on mineral surfaces, favoring five-membered hydroxamic-(O-O)-Ce/Ca complexes, and reacts more strongly with Ce atoms than Ca atoms. SS primarily forms covalent bonds with metal atoms on mineral surfaces via the SiO(OH)3− component, and OHA and SS compete for adsorption on the mineral surfaces. OHA has a stronger affinity for bastnaesite, whereas SS shows the highest affinity for fluorite, followed by parisite, and the weakest affinity for bastnaesite.

Efficient sulfidization-free flotation of chrysocolla enabled by specific synergistic effects of ammonium sulfate and octyl hydroxamic acid

Due to its poor sulfidization effect and environmental issues, the traditional sulfidization–xanthate method faces challenges in chrysocolla flotation. Addressing these, our study pioneers a sulfidization-free approach using ammonium sulfate as an activator in an octyl hydroxamic acid (OHA) collector system. This innovation propels flotation recovery from 34.10 % to an impressive 98.43 %. Infrared spectroscopy and adsorption tests confirm that ammonium sulfate improves OHA’s adsorption on chrysocolla. X-ray photoelectron spectroscopy (XPS) analysis reveals a significant rise in C–C and C-N bonds related to OHA on the mineral surface post-activation. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) analysis shows a rougher mineral surface with filamentous precipitates and a higher surface nitrogen atom concentration. Density Functional Theory (DFT) calculations elucidate NH3′s role in disrupting the hydration layer, exposing more Cu sites for enhanced OHA attachment. The Cu 2p shift observed on the mineral surface, along with state density analysis, further confirms the chemical adsorption of OHA on chrysocolla’s Cu sites facilitated by ammonium sulfate. This study introduces a novel NH3-enhanced OHA adsorption method, offering a promising strategy for the efficient flotation of chrysocolla.

N1,N10-dihydroxydecanediamide: Its separation performance and action mechanism for malachite, calcite and quartz

In this study, a novel collector, N1,N10-dihydroxydecanediamide (DHH) was synthesized in our lab and introduced in flotation of malachite ore. The separation performance and action mechanism of DHH were explored and compared with octyl hydroxamic acid (OHA). The results of single mineral flotation tests indicated that DHH exhibited a stronger collecting ability to malachite and better selectivity against quartz and calcite than OHA, and floated out 94 % malachite, 8.5 % quartz and 17 % calcite at pH = 10 with a collector concentration of 60 mg/L. The FTIR spectra, zeta-potential tests and XPS tests proved that DHH could absorb onto malachite surface though a chemical mode. DFT calculation results showed that DHH anion owned a stronger affinity to malachite than DHH molecular and OHA anion/molecular, and its bis-minerophilic groups could form C(=O)NHO-Cu bond with surface Cu atom. It exhibited that DHH was an excellent candidate and capable for high efficiency flotation of malachite ore.

Влияние состава гидроксамовых кислот на показатели флотации перовскита.

On a sample of perovskite-bearing ore of the testing of reagents-collectors from the class of hydroxamic acids, differing in the structure of the hydrocarbon radical, was carried out. The reagents based on octanoic acid and acids of vegetable oils — coconut and tall oil — were considered. It is shown that in the alkaline pH range the rough flotation is more active, and a considerable amount of gangue minerals is transferred to the froth product. Strong attachment of the collector on all minerals determines low efficiency of re-cleaning operations in alkaline conditions. The optimum pH of flotation is pH = 6.2–6.5. Increase in the length of hydrocarbon radical above 10 carbon atoms leads to a significant decrease in the selectivity of the collector action. Reagents based on coconut and tallic acids actively float both perovskite and gangue minerals. Of the reagents considered, octylhydroxamic acid is characterized by the most optimal flotation properties and provides obtaining perovskite concentrate with TiO2 ~49–50 %.

Effect of an Environment-Friendly Depressant on the Flotation of Bastnaesite and Fluorite

To overcome the difficulty of separating bastnaesite from fluorite through the flotation technique, the present study examined the suitability of sodium alginate (SA) as a depressant in the flotation process. The effect of SA on the flotation separation of bastnaesite and fluorite was evaluated using micro-flotation tests, zeta potential measurements, adsorption density measurements, Fourier infrared spectroscopy, and X-ray photoelectron spectroscopy. The micro-flotation results showed that SA exerted a strongly detrimental effect on fluorite flotation, while slightly affecting bastnaesite flotation. The surface chemistry results revealed that the -COO- and HO- functional groups in SA coordinated with Ca2+ on the fluorite surface, which induced hydrophilicity and hindered adsorption in the subsequent octylhydroxamic acid as a collector. However, the interaction of SA with the bastnaesite surface was marginal and did not affect the anchoring of the collector on the surface of bastnaesite. Based on these results, the present study proposes a possible model for the interaction of SA on the surfaces of the two minerals, laying a foundation for the flotation separation of bastnaesite from fluorite with SA as an environmentally benign depressant.

Adsorption of salicyl hydroxamic acid and octyl hydroxamic acid mixture on the cassiterite minerals

Salicylhydroxamic acid (SHA) and octyl hydroxamic acid (OHA) are two commonly used hydroxamic acid-based collectors in fine cassiterite flotation. While some reports suggest that a mixture of OHA and SHA yields superior results compared to their individual use, there is a lack of experimental exploration and theoretical analysis. In this study, the flotation performance and the associated adsorption mechanism of SHA, OHA and their mixture on fine cassiterite particles was systematically investigated. The results demonstrate a synergistic effect between SHA and OHA in enhancing fine cassiterite flotation, with the most significant enhancement occurring at a 1:1 mass ratio under the natural pH conditions. This finding is corroborated by contact angle and zeta potential tests. When both SHA and OHA are present, SHA likely attaches to the cassiterite surface via chemisorption in the form of a five-membered chelate ring, while OHA adheres through physical adsorption, primarily establishing hydrogen bonds with oxygen sites on the cassiterite surface or with SHA molecules. The adsorption ratio of SHA to OHA onto cassiterite surfaces is approximately 69%: 31% when an equal mass of SHA and OHA interact with cassiterite under the natural pH condition.

Synthesis and application of dithiocarbamate oxadiazole thione for flotation separation of malachite from quartz and calcite

In this paper, 5-methyl hexyldithiocarbamate-1,3,4-oxadiazole-2-thione (MHCODT) was synthesized for the first time and introduced as a flotation collector in malachite flotation separation process from quartz and calcite. During the micro-flotation experiment, it was found that MHCODT showed stronger flotation ability and selectivity for malachite than conventional collector octyl hydroxamic acid (OHA), and achieved effective separation and enrichment of malachite. Measurements of contact angles, ζ-potentials and UV spectra demonstrated that MHCODT specifically adhered to the surface of malachite rather than quartz and calcite. Then, FTIR and X-ray photoelectron spectroscopy (XPS) demonstrated that Cu of malachite surface combined with S and N of MHCODT to form MHCODT-Cu(I) complexes, accompanied by the reduction of divalent Cu. The result of density functional theory (DFT) method indicated that the CS bonds and NH bonds in oxadiazole thione and the dithiocarbamate groups were the chemical reaction center. Based on the above test results, the adsorption models of MHCODT-Cu+ and MHCODT-Cu2+ were proposed.

N-[6-(hydroxyamino)-6-oxohexyl]octanamide: A collector derived from the structure of octyl hydroxamic acid and its application in bastnaesite flotation

Bastnaesite has always been faced significant challenges in its flotation separation from its associated gangue minerals like fluorite. Despite being a commonly employed collector for oxide mineral flotations, octyl hydroxamic acid (OHA) still exhibits insufficient selectivity. Consequently, a novel hydroxamic acid, N-[6-(hydroxyamino)-6-oxohexyl]octanamide (NHOO), is synthesized and employed as a collector in bastnaesite flotation, building upon the structure of OHA. Flotation experiments under neutral conditions demonstrate the effective ability of NHOO to achieve a difference of nearly 60% in the recoveries between bastnaesite and fluorite during their separation. Concordant outcomes from zeta potential characterizations, adsorption tests, and X-ray photoemission spectroscopy validate heightened adsorption quantities of NHOO on bastnaesite surface relative to fluorite under identical dosage conditions. Ab initio calculations unveil the capability of NHOO to establish a pentacoordinate chelate ring on bastnaesite surface, whereas on fluorite, it can only form a singular chemical bond. Consequently, NHOO shows a considerably lower energy associated with its adsorption on bastnaesite surface in comparison to its energy on fluorite surface.

Synergetic adsorption of dodecylamine and octyl hydroxamic acid on sulfidized smithsonite: Insights from experiments and molecular dynamics simulation

The escalating demand for zinc resources has been positioning zinc oxide ore as an invaluable supplementary resource to cater to zinc supply requirements. There is now a growing focus on optimizing the efficient flotation of zinc oxide ore. In this study, experiments were conducted using dodecylamine (DDA) and octyl hydroxamic acid (OHA) as combined collectors, along with pre-sulfidization by sodium sulfide, to enhance smithsonite flotation. The use of the DDA–OHA combined collector resulted in a significant improvement of over 25% in the recovery when compared with the use of DDA as a single collector. Adsorption capacity measurements and zeta potential measurements provided evidence for the synergistic effect of DDA and OHA. Solution surface tension measurements indicated that the combined collector system helped stabilize the flotation foam. Analysis of treated smithsonite by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy further verified the chemical and physical adsorption of DDA and OHA on the surface of smithsonite. The measurement of contact angles of treated smithsonite showed that the combined collector effectively increased the hydrophobicity of the mineral. Molecular dynamics simulations suggested that OHA and DDA undergo multilayer adsorption on the sulfidized smithsonite (101) surface and that the presence of OHA promotes the adsorption of DDA.

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.

The selective adsorption and flotation separation of spodumene from feldspar using a novel iron-group multiple ligand collector

Spodumene and feldspar have little difference in flotability due to their similar crystal chemistry properties. Fe-octyl hydroxamic acid (OHA) (iron complexes of octyl hydroxamic acid) demonstrates excellent selectivity but restricted collecting performance in spodumene flotation. In this work, we added sodium dodecyl sulfate (SDS) into Fe-OHA to obtain a novel multiple ligand collector, which was named Fe-OHA-SDS to enhance the collection ability of Fe-OHA. The efficient separation of spodumene from feldspar (the recovery difference was about 84 %) was achieved by Fe-OHA-SDS without adding depressants and foaming agents at pH 6.2. The separation mechanisms were explored by Zeta potential, contact angle, in-situ microcalorimetric, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) measurements. The findings revealed that Fe-OHA-SDS was more easily bonded to the spodumene surface than the feldspar surface. Meanwhile, the adsorption of Fe-OHA-SDS significantly expanded the hydrophobicity differences on these two mineral surfaces. The Fe-OHA-SDS was adsorbed on the spodumene surface through the Fe-O bond, which differed from the interaction mechanism of traditional mixed collectors on mineral surfaces. Therefore, Fe-OHA-SDS was an efficient collector with potential application value in spodumene flotation.

Improve Bastnaesite Flotation via Synergistic Effect of Octyl Hydroxamic Acid and Octyl Phenol Ethoxylated Surfactants

ABSTRACT The large loss of fine-grained bastnaesite has become an increasingly important issue restricting the development of rare earth ore flotation industry. To solve this issue, a new collector mixture that combines octyl hydroxamic acid (OHA) and octyl phenol ethoxylation (OP10, the number of ethylene oxide groups is 10) is proposed to be used to improve the flotation of bastnaesite. The flotation adsorption mechanism of OHA/OP10 on bastnaesite was investigated by a series of experimental and analytical tests. The results showed that when the molar ratio of OHA/OP10 was 3:1, the OHA/OP10 combination significantly improved the recovery of −74 + 38 μm and −15 μm bastnaesite compared with only OHA. Optical microscopy revealed that mixed OHA/OP10 had a beneficial effect on fine-grained bastnaesite aggregation. In addition, the results of the zeta potential test, fluorescence spectrum analysis, and XPS analysis showed that OHA and OP10 were co-adsorbed on the surface of bastnaesite.

Synergistic Adsorption and Molecular Arrangement of Mixed Surfactants at the Air/Water Interface

The self-assembly of mixed surfactants at the air/water interface plays a crucial role in mineral flotation separation. This study aimed to investigate the molecular arrangement and synergistic adsorption of mixed surfactants at the air/water interface using molecular dynamics (MD) simulation and surface tension measurement. The stability of mixed surfactant solutions was also measured using dynamic light scattering and ζ potential. We investigated the mixture of octylhydroxamic acid (OHA) and dodecanol (DOD) surfactants at different weight ratios. The surface activity of the OHA/DOD mixture was characterized in detail, including the relative concentration distribution, structural properties, and radial distribution function. The MD simulations revealed that OHA/DOD was inserted into the water as a headgroup at the air/water interface, and the carbon chain extended into the air. A strong synergistic effect was observed between the two surfactants, and a dense monolayer film was formed at the air/water interface, demonstrating higher surface activity. With an increase in the DOD ratio, the hydrogen bond between the OHA headgroup and water molecules became stronger. The order of surface activity of the mixture was OHA:DOD = 1:1 > OHA:DOD = 2:1 > OHA:DOD = 4:1. In the temperature range from 24 to 30 °C, the surface tension decreased and the critical micelle concentration increased with increasing temperature. The addition of DOD changed the conformation of the mixed surfactants, which was beneficial to the aggregation of OHA/DOD complexes. When OHA:DOD = 1:1, the average particle size was the largest and the formed micelles were the most stable. The experimental results are consistent with the surface tension and simulation results.

Characterization of Octyl Hydroxamic Acid as Inhibitor on Cu Chemical Mechanical Polishing

As an inhibitor for copper (Cu), Octyl hydroxamic acid (OHA) has been extensively studied through a combination of density functional theory (DFT) and experiments. Our findings indicate that using a concentration of 3 mM OHA as an inhibitor can lead to a remarkable removal rate (RR) and surface quality when the pH is at 10. Tafel analysis of potentiodynamic polarization plots was performed to demonstrate that OHA can lower the corrosion current. Further insight into the adsorption behavior of OHA on the Cu surface was obtained through a comprehensive study combining X-ray photoelectron spectroscopy (XPS), DFT calculations, and adsorption isotherm model analysis.

Adsorption kinetic studies of octyl hydroxamic acid on galena surface

In this work, octyl hydroxamic acid (OHA) was utilized as a collector for galena flotation, and its adsorption kinetics on galena surface was fully studied. The experimental results showed that the optimal pH for the adsorption was 9.5 and the adsorption equilibrium was reached at 2 h. It is important to emphasize that this process was an exothermic, spontaneous, ordered and monolayer adsorption. In addition, the adsorption of OHA on galena surface could change the surface charges and improve the surface hydrophobicity, as identified by zeta potential and contact angle measurements, respectively. XPS analysis demonstrated that OHA chemisorbed on the galena surface mainly through the binding reactions between the two O atoms of -C(=O)–NHOH group and Pb(OH)+ on galena surface at pH 9.5. Flotation experimental demonstrated that 4 × 10-5 mol/L OHA could collect 98.62% of galena at pH 9.5, which was higher than that by sodium isopropyl xanthate (SIPX) under the same experimental conditions.

The effect mechanism of calcite or quartz particles towards bastnaesite flotation with octyl hydroxamic acid

In this paper, the effect of calcite and quartz on bastnaesite flotation with octyl hydroxamic acid (OHA) collector was studied by adsorption, contact angle, optical microscopy, dynamic froth stability, AFM and extended DLVO theory. The findings inferred that the affinity of OHA to these minerals was followed as bastnaesite > calcite ≫ quartz, resulting in the superior aggregates among bastnaesite particles. In OHA flotation system, bastnaesite promoted the flotation recovery of calcite through their hydrophobic hetero-aggregates, while calcite weakened the floatability of bastnaesite via breaking the compact bastnaesite aggregates. Thus, OHA exhibited an unsatisfactory flotation separation of bastnaesite from calcite. For quartz, its hetero-aggregation with bastnaesite hardly occurred, and bastnaesite increased the dynamic froth stability and produced more water foam which entrained more quartz particles into the flotation concentrates. Nevertheless, the floatability difference of bastnaesite to quartz was enough for OHA to realize a high selective flotation recovery of bastnaesite.

Surface chemistry of xanthan gum interactions with bastnaesite and fluorite during flotation

Rare earth (RE) minerals are resources crucial to mining strategies. In particular, bastnaesite is a major mineral from which rare earth elements (REEs), especially light rare earth elements (LREEs), can be extracted. However, the separation of bastnaesite and fluorite via flotation is challenging owing to their similar physical and chemical properties. In this study, xanthan gum (XG) was evaluated as a novel depressant of bastnaesite and fluorite in an octyl hydroxamic acid (OHA) system. The flotation behavior and surface chemistry by which the XG interacted with the bastnaesite and fluorite were investigated via analyses of micro-flotation tests, adsorption density measurements, zeta potentials, Fourier transform infrared spectra (FTIR), and X-ray photoelectron spectra (XPS). The micro-flotation results showed that the XG was an efficient selective depressant for the fluorite but had minimal impact on the bastnaesite. The results of the adsorption density and zeta potential analyses indicated that the adsorption of the XG occurred on both the bastnaesite and fluorite surfaces. They also indicated that the XG hindered the subsequent adsorption of the OHA on the surface of the fluorite, but the OHA was able to attach to the surface of the bastnaesite. The results of the FTIR and XPS analyses revealed that in the interaction between the XG and fluorite, chemical and hydrogen bonding adsorption occurred via complexation between the –COO- and –OH groups within the XG and the Ca or F sites on the surface of the fluorite, whereas only hydrogen bonding and electrostatic attraction occurred between the XG and bastnaesite surface. These results provide a more robust theoretical basis and sound guidance for the selection of effective depressants in the flotation separation of bastnaesite and fluorite.

Quantum chemistry assisted screening of zircon flotation collectors

This technical note proposed a new approach to screen flotation reagents based on fast and accurate batch quantum chemistry calculations. Accordingly, the ethyl-functional group (EFG) data bank was used to calculate the reaction-free energy of solidophilic groups with possible metal hydroxide ions (the representatives of mineral surface sites). Then the obtained solidophilic groups possessing the best binding affinity with surface sites were linked with the C8 hydrocarbon chain to form the collectors [n-octyl phosphoric acid (nOPA), octyl hydroxamic acid (OHA)]. The flotation results showed that the nOPA and OHA had much better flotation performance than the octanoic acid. These results showed that the quantum chemistry-assisted rational screening and design of flotation reagents was accurate and feasible. This work can shed new light on screening new and novel flotation reagents with virtual screening techniques.