Xanthate Solution Research Articles

Removal of Sodium Isopropyl Xanthate by Capacitive Deionization Process

This study investigated the removal of sodium isopropyl xanthate (SIPX) by capacitive deionization using ion exchange resin/PVDF electrode. The electrode was prepared by coating a layer of ion exchange resin (Amberlite FPA54) and polyvinylidene fluoride (PVDF) on the carbon electrode. Batch experiments showed that 96% of SIPX was removed via the electrosorption and electrochemical advanced oxidation processes at 1 V. Carbon disulfide (CS2) was generated as a by-product of the xanthate oxidation. Adsorption/desorption cycle tests revealed that the ion exchange resin/PVDF electrode has high adsorption capacity, and the maximum adsorption could not be achieved within 60 min of adsorption times. The total xanthate removed in the final adsorption stage of eight cycles was 323 mg/m2, corresponding to 34.1% of xanthate from a 20 mg/L xanthate solution that flowed 0.4 mL per min at 1 V for 60 min of adsorption. In the desorption stage, some of the adsorbed xanthate was released back into the solution and oxidized to CS2, which was adsorbed by the electrodes in the following adsorption stage.

Biopolymer-enhanced delivery of reactive sulfide reagents for in-situ mercury remediation of heterogeneous contaminated soils

Mercury pollution from natural and anthropogenic sources demands effective remediation. This study focuses on optimizing a chemical stabilization approach using sulfur-containing compounds to create stable mercury sulfide (HgS) and immobilize elemental mercury in polluted soils. We propose using xanthan gum biopolymer to enhance the in-situ delivery of sulfide microparticles, overcoming soil heterogeneities due to its non-Newtonian behavior. Stability tests indicated that increased biopolymer concentration enhances particle stability due to the viscous and shear-thinning behavior of the polymer solutions. Various combinations (12 solutions) of xanthan polymer, pyrite microparticles, and sulfide-containing reagents were tested in batch experiments. Pyrite microparticles slightly reduced the xanthan solution's viscosity while retaining its non-Newtonian character. All solutions effectively transformed liquid mercury droplets into cinnabar, demonstrating successful mercury stabilization. Notably, solutions containing PIAX and SIPX, xanthate organosulfur compounds, significantly reduced the dissolved concentration of elemental mercury. Column experiments demonstrated xanthan gum's superior performance for in-situ injection of pyrite microparticles and sulfide mixtures into the soil compared to conventional water injection. At a polymer concentration of 4 g/L, a stable displacement front and an 88 % recovery of the initially injected particle-suspension density were achieved. The combined effects of xanthate's floating behavior and xanthan gum's shear-thinning nature substantially enhanced the delivery of pyrite microparticles in porous media for soil mercury remediation. This combination reduced the aqueous elemental mercury concentration in artificially polluted sand by up to 97 %, particularly with the xanthate organosulfur compound, PIAX. Xanthate has a higher potential to react with elemental mercury to form cinnabar compared to sodium thiosulfate. Additionally, the pyrite microparticles, rendered hydrophobic in xanthate solutions, integrated into the mercury droplets, forming a black paste. This study introduces a promising approach for efficient elemental mercury stabilization in contaminated soils by integrating biopolymers, reactive soluble compounds, and pyrite microparticles for sustainable decontamination.

AgCl/g-C3N4/Ti-MOFs photocatalytic composite for visible light degradation of xanthate derived from mineral processing industries

Large amounts of xanthate wastewater generated from mineral beneficiation significantly threaten the ecological environment. MOF photocatalysis is considered as a promising method for the removal of xanthate that is environmentally friendly and has high efficiency. However, the defects in MOFs limit their large-scale application due to poor visible light absorption efficiency and stability in water. In this study, a novel composite material composed of g-C3N4/AgCl/Ti-MOFs was prepared, and the catalytic degradation effect of butyl xanthate solution under different catalyst ratios and reaction conditions was investigated. The results showed that the composite could still maintain excellent catalytic performance (degradation rate of 99.5% within 90 min) under xenon light and low dosage. The characterization results showed that this excellent photocatalytic performance could be attributed to the following three points: 1) The material could absorb up to 670 nm visible light absorption capacity; 2) excellent stability was achieved (86% degradation efficiency after six cycles); and 3) the Schottky junctions formed by Ag0 and other materials in the composite increased the transfer rate of e−/h+. The possible photodegradation mechanism was proposed according to UV–vis DRS and trapping experiments.

Electrochemical advanced oxidation for removal of xanthate from flotation process water

In this work, the removal of xanthate from flotation process water by electrochemical advanced oxidation processes (EAOPs) was investigated. An electrochemical cell was fabricated using a pair of carbon electrodes as the anode and cathode. Electrodes were prepared by depositing an aqueous slurry of activated carbon and PVA binder onto graphite sheets. Carbon disulfide (CS2) was produced during the process and removed to some extent by absorption of carbon electrodes and/or further oxidation to sulfate (SO42−).The effect of operating parameters such as applied voltage, flow rate, and influent concentration on process efficiency was evaluated to achieve efficient xanthate removal. Application of various potentials ranging from 1 V to 7 V showed that xanthate removal efficiency increased at higher voltages. The effluent concentration was cleaner and the salt removal efficiency was higher at slower flow rates. The highest removal efficiency of 95% was achieved at a flow rate of 0.5 mL/min. Since the density of ions between the electrodes increased with increasing influent concentration, the total xanthate removal increased from 599.4 mg/m2 at 5 mg/L influent concentration to 12834.2 mg/m2 at 40 mg/L. Long-term stability tests showed that electrode performance degraded steadily and the removal efficiency decreased from 85% to 56% in 30 h.Batch mode experiments in the presence of ion exchange membranes showed that xanthate was oxidized to CS2 at 0.8 V and 1.0 V and to monothiocarbonate (ROCSO−) at 1.2 V. 96% of xanthate was removed from 5 mg/L xanthate solution at a flow rate of 0.5 mL/min at 1.0 V.The effect of real mine water components on xanthate removal efficiency was investigated by using flotation process water from a copper mine in Turkey. The results showed that the process efficiency decreased from 67% to 32% in the presence of mine water, which could be attributed to electrode fouling.

Establishment of a Hydrometallurgical Scheme for the Recovery of Copper, Nickel, and Cobalt from Smelter Slag and Its Economic Evaluation

In pursuit of carbon neutrality, the demand for metals that are necessary for the development of clean energy technologies is rapidly increasing. Metallurgical waste, such as slag, presents a promising secondary source of these key metals. This research aims to develop an eco-friendly hydrometallurgical process to recover Cu, Ni, and Co from discarded copper/nickel slag. High-pressure acid leaching (HPAL) was used to selectively leach Ni, Cu, and Co from the fayalite slag, yielding high leaching efficiencies of 99.9%, 89.4%, and 99.9%, respectively, with low Fe and Si tenors to the pregnant leach solution (PLS). The solvent extraction (SX) technique utilizing LIX 984N was used to selectively extract and enrich copper from the dilute PLS to about 23 g/L Cu with a very low Fe concentration of 0.05 g/L. Potassium amyl xanthate (PAX) solution was used to form Ni and Co xanthate complexes from the raffinate solution. Nickel was selectively recovered using ammonia solution, while the cobalt xanthate complex was thermally decomposed and recovered as cobalt oxide solids of about 25 wt.% Co. A comprehensive process flowsheet is presented. Furthermore, to realize the real application of the developed slag cleaning process, a preliminary economic evaluation was performed.

Cryo-ToF-SIMS study of sodium isobutyl xanthate adsorption on sulfide minerals

The chemical properties of the mineral/solution interface have a decisive influence on the flotation behavior of minerals. Here, chalcopyrite, chalcopyrite-pyrite mixture, and chalcopyrite-galena mixture were reacted in 0.1 mM sodium isobutyl xanthate solution at natural pH, then centrifuged, fast-frozen, and characterized with time-of-flight secondary ion mass spectrometry at –125 °C (Cryo-ToF-SIMS) in comparison with the samples thawed in vacuum and measured at room temperature (RT-ToF-SIMS). Cryo-ToF-SIMS of fast-frozen mineral wet pastes allows quasi-in situ characterization of chemical species within the mineral/solution interfacial layer. It was found that dixanthogen was the predominant species of xanthate adsorption products on chalcopyrite and pyrite, while that of galena was lead isobutyl xanthate. In particular, due to the interaction effects between sulfide minerals, the formation of dixanthogen at the mineral/solution interface of chalcopyrite was promoted and inhibited by pyrite and galena, respectively, and the lead ions dissolved from galena were adsorbed to the chalcopyrite surface, resulting in xanthate to react with adsorbed species of lead ions to form lead isobutyl xanthate. This study also observed that the mineral/solution interfacial layer of chalcopyrite-galena mixture was more deficient in sodium ions and calcium ions than those of chalcopyrite and chalcopyrite-pyrite mixture; we proposed that this phenomenon was caused by the repulsion of sodium ions and calcium ions by lead ions dissolved from galena in the electric double layer of minerals.

Effect of different cure systems on natural rubber/nanocellulose nanocomposites in rheological, physical-mechanical, aging, and mechanical properties

The effect of different crosslink structures was studied in nanocomposites obtained by co-precipitation of natural rubber (NR) latex and aqueous solution of cellulose xanthate for obtaining nanocellulose. Cure systems characterized as conventional (CV), semi-efficient (SEV), and efficient (EV) were used in compositions of NR and also in natural rubber/cellulose (NR/CEL) nanocompositions with 15 phr of cellulose. The characterization of the developed compositions was based on rheological, physical-mechanical, aging, and mechanical properties. The obtained results allowed the conclusion that cellulose is a reinforcing filler as it promoted a significant increase in all these properties, that were sensitive to the cure systems used and protects NR from accelerated aging. The experimental results are presented and discussed also by Payne effect, entropy (ΔS), and Gibbs free energy (ΔG) to enable an understanding on cellulose distribution throughout NR influenced by the different cure systems.

The Mechanism of the Effect of Pre-Magnetized Butyl Xanthate on Chalcopyrite Flotation

In this work, we applied the technology of magnetic treatment to the flotation of chalcopyrite. The mechanism of the effect of pre-magnetized butyl xanthate on chalcopyrite flotation was studied using monomineral flotation tests, adsorption tests, conductivity tests, Fourier transform infrared spectroscopy (FTIR), etc. The monomineral flotation test results showed that, after the magnetization pretreatment of butyl xanthate solution, the chalcopyrite flotation recovery was increased by nearly two percentage points, and the dosage was reduced by 4–10 mg/L at the same recovery. The adsorption, FTIR, dissolved oxygen, and conductivity test results all showed that the magnetization pretreatment increased the dissolved oxygen content and promoted the oxidation of butyl xanthate to double xanthate with better selectivity to chalcopyrite. An electrochemical analysis showed that the magnetization pretreatment of butyl xanthate reduced the corrosion potential and corrosion current density of chalcopyrite surface and inhibited the self-corrosion process of chalcopyrite surface. The flotation test results of actual copper sulfide ore showed that pre-magnetized butyl xanthate could increase the copper recovery of copper concentrate by 3.06 percentage points and the sulfur recovery of sulfur concentrate by nearly 3 percentage points, and effectively reduce the mutual content of copper and sulfur concentrates.

Sb2S3 thin films by ultrasonic spray pyrolysis of antimony ethyl xanthate

Synthesis of antimony chalcogenides, especially Sb2S3, by facile and area scalable in-air chemical methods, such as spray pyrolysis, from cost-effective chemicals is certain to accelerate development of the related thin film solar cell technology. In this study, antimony ethyl xanthate, a scarcely studied halogenide-free precursor, is proven to be suitable for the deposition of conformal phase pure crystalline Sb2S3 thin films via ultrasonic spray pyrolysis in air by a two-step process. First, a solution of antimony ethyl xanthate with thiourea in a molar ratio of 1/3, or with thioacetamide in a molar ratio of 1/10 was sprayed onto a glass/ITO/TiO2 substrate by ultrasonic spray pyrolysis at 215°C to yield amorphous phase pure Sb2S3 thin films. Second, performing post-growth heat treatment in vacuum at 225°C, was the key to produce phase pure conformal thin films of crystalline Sb2S3 (Eg 1.8 eV) with S/Sb atomic ratio of 1.46 by using thiourea, and 1.41 by using thioacetamide, respectively. Spraying solutions of antimony ethyl xanthate at ≥135°C resulted in the formation of the Sb2O3 phase. Adding thiourea or thioacetamide to the spray solution prevented the oxidation of the growing Sb2S3 layer during deposition at 135°C, 165°C, and 215°C. The suppressed oxidation of Sb2S3 layers is attributed to the liquid state of thiourea and thioacetamide in these conditions.

Preparation of nanocomposites of PbS quantum dots dispersed in MAPbI3 matrix from precursor solution of Pb xanthate

Organic-inorganic hybrid perovskites attract attentions because of their unique electro-optical properties which are expected to be applied to various devices. The perovskite compounds are generally prepared from precursor solutions consisting of two materials, AX and BX2 for ABX3. Generally, methylammonium lead triiodide (MAPbI3) perovskite is formed from the precursor solution consisting of methylammonium iodide (MAI) and lead iodide (PbI2). In this report, we select Pb(-S-C(S)-OR)2 (lead xanthate, abbreviated as Pb(XT)2) as the perovskite precursor instead of PbI2. We found that the precursor solutions consisting of the MAI and the Pb(XT)2 give nanocomposites consisting of MAPbI3 and PbS nanomaterials including PbS quantum dot without changing the MAPbI3 bandgap. In this report, nanocomposites prepared from precursors consisting of Pb(XT)2/MAI with various ratios are analysed by using XRD, XPS, TG-DTA, TEM and UV/VIS spectroscopy.

An Investigation of the Adsorption of Xanthate on Bornite in Aqueous Solutions Using an Atomic Force Microscope

An atomic force microscope (AFM) was applied to study of the adsorption of xanthate on bornite surfaces in situ in aqueous solutions. AFM images showed that xanthate, i.e., potassium ethyl xanthate (KEX) and potassium amyl xanthate (PAX), adsorbed strongly on bornite, and the adsorbate bound strongly with the mineral surface without being removed by flushing with ethanol alcohol. The AFM images also showed that the adsorption increased with the increased collector concentration and contact time. Xanthate adsorbed on bornite in a similar manner when the solution pH changed to pH 10. The AFM force measurement results showed that the probe–substrate adhesion increased due to the adsorption of xanthate on bornite. The sharp “jump-in” and “jump-off” points on force curve suggest that the adsorbate is not “soft” in nature, ruling out the existence of dixanthogen, an oily substance. Finally, the ATR-FTIR (attenuated total reflection-Fourier-transform infrared) result confirms that the adsorbate on bornite in xanthate solutions is mainly in the form of insoluble cuprous xanthate (CuX) instead of dixanthogen. This xanthate/bornite adsorption mechanism is very similar to what is obtained with the xanthate/chalcocite system, while it is different from the xanthate/chalcopyrite system, for which oily dixanthogen is the main adsorption product on the chalcopyrite surface. The present study helps clarify the flotation mechanism of bornite in industry practice using xanthate as a collector.

Fabrication of Cellulose Sponge: Effects of Drying Process and Cellulose Nanofiber Deposition on the Physical Strength

Cellulose sponge was fabricated by regenerating cellulose from a xanthate solution. The solution, which contained sodium phosphate particles as a template to create sponge porosity, was dried at 55, 65, 75 and 85 °C for 2, 4, 6, and 8 h. Mass transfer during the initial and last stages of drying was controlled in terms of temperature and concentration differences, respectively. The activation energy and pre-exponential factor of the mass transfer coefficient were -51,841.947 kJ mol-1 and 7.26×109 m-2 h-1, respectively. Regenerated cellulose contained a crystalline type of cellulose II, and the crystallinity was independent of drying conditions. At a low drying temperature (T≤55 °C) and short drying period (t≤2h), the cellulose was unregenerated. At higher temperatures and longer drying periods, no relationship between temperature and physical strength was observed. Cellulose nanofiber (CNF) was added to the xanthate solution at a ratio of 1:100 of CNF to linter cellulose for xanthation; however, this did not affect the physical strength of the cellulose sponge for both mechanically and chemically fabricated CNF.

AFM Study of Pyrite Oxidation and Xanthate Adsorption in the Presence of Seawater Salts

The effect of seawater ions presents a great challenge to theories about mechanisms of pyrite oxidation, collector adsorption, and surface reactions. As the use of seawater is key to the sustainability of the mining industry in regions without fresh water, there is a need to study the surfaces of minerals and products that are formed in the presence of seawater salts. In this study, atomic force microscopy (AFM) was used to analyze the topography of pyrite surfaces subjected to treatments, including oxidation and exposure to xanthate and solutions of seawater salts and xanthate, at pH 8.5. Topographic details were related to surface products. The results showed that xanthate was adsorbed without hindrance on oxide-free pyrite which validated one well-known model. The results also showed that pyrite oxidized forming a structure of interconnected pillars and that xanthate was adsorbed on the top and skirt of these pillars; the experimental evidence on the increase in the height and width of these pillars validated another well-known model. In the presence of seawater salts, the cations covered the surface of the pyrite, suppressing collector adsorption regardless of the dose. The results are expected to help in decisions about the flotation of sulfide minerals in water with limited metallurgical quality.

Zeta Potential of Pyrite Particles in Concentrated Solutions of Monovalent Seawater Electrolytes and Amyl Xanthate

Charge screening and adsorption capacity of monovalent ions onto pyrite (Py) in aqueous suspensions and the effect of potassium amyl xanthate (PAX) has been studied by measuring the changes in zeta potential (zp) versus pH with streaming potential. PAX addition in the absence of salts leads to an increase in |zp| suggesting dissolution of the surface ferric hydroxides and recovery of bare Py, corroborating existing theories. In the presence of salt, addition of PAX at pH > 6, for which hydroxides interference in not expected, has little effect over the zp, except when Li is present. The water network around the polar head of PAX is expected to be similar to that of hydrated Li+ facilitating the linkage between them and, thus, the formation of Li-mediated Py–PAX bridges. We speculate that these bridges lead to a xanthate shield around anionic sites on Py, decreasing |zp|. An increased PAX dose amplifies the effect of Li as a Py activator but only at low salt. At high salt concentrations, >0.01 M, PAX molecules do not find room to percolate to the surface of Py. Results for monovalent cations should improve our understanding of copper flotation processes in the presence of Py in saltwater.

Decomposition of flotation reagents in solutions containing metal ions. Part I: Gaseous compounds from xanthate decomposition

The mining industry faces increasing regulatory pressure from hazardous reagents used in mineral processing operations. Xanthates, a common class of collectors used in flotation, have come under scrutiny in recent years for their potential to present significant HSE (Health, Safety and Environmental) hazards resulting from their propensity to generate toxic compounds (such as CS2) during transportation, storage, use and disposal. Interactions between xanthate and metal ions are ubiquitous in flotation systems, and the products formed are known to influence mineral separation efficiency and selectivity. The effect of such interactions (and the products formed) on the overall decomposition of xanthate is not well known. A method was developed to enable a systematic and integrated analysis of compositional changes in gas, liquid and precipitate phases of a closed system comprising xanthate solution and metal ions (Cu2+ or Fe3+). A study of compositional changes in the gas phase indicated that Cu2+ suppresses decomposition of xanthate into CS2, and the magnitude of the effect increases with an increase in temperature. Fe3+ ions, on the other hand, promote decomposition; however, the effect of increasing temperature on decomposition is confounded by the oxidative effect of Fe3+ ions. How Cu2+ and Fe3+ ions affect decomposition in terms of the decomposition products is the focus of Part I and the mechanistic aspects of the effect of Cu2+ and Fe3+ ions are discussed in Part II.

Preparation, characterization, and photoluminescence property of core-shell (BiO)2CO3@Bi2S3 nanowires

Bi2S3-containing nanocomposites have attracted considerable attention due to their outstanding photocatalytic activity. However, little study was focused on the preparation and PL property of core-shell (BiO)2CO3@Bi2S3 nanowires. Herein we report the in situ preparation, characterization and PL property of (BiO)2CO3@Bi2S3 core-shell nanowires. (BiO)2CO3@Bi2S3 core-shell nanowires with different sulfur content were synthesized in situ by irradiating (BiO)2CO3 nanowires in xanthate solution. These nanowires showed strong photoluminescence (PL) emission from violet to blue light range. The XRD patterns, EDS mapping images, HRTEM images, and XPS results demonstrated the formation of Bi2S3 shell on the surface of (BiO)2CO3 core. SEM and TEM images indicated that the core-shell nanowires were 20–40 nm in diameter and up to tens of micrometers in length. The sulfur content in core-shell nanowires increased from 0.31% to 1.13% with increasing reacted times. EDS mapping showed that S element was uniformly distributed on the surface of nanowires. The PL peaks at 395, 418, 441 and 467 nm of (BiO)2CO3@Bi2S3 core-shell nanowires with low S concentration were contributed to the intrinsic emission of (BiO)2CO3 core, Bi-containing intermediate-induced emission, BiO cluster-induced emission, and surface defect-induced emission of (BiO)2CO3 core, respectively. A new shoulder peak at 427 nm appeared in the PL spectrum of (BiO)2CO3@Bi2S3 core-shell nanowires with 1.13% S, which could be contributed the electronic coupling effect between Bi2S3 shell and (BiO)2CO3 core. We anticipate that the core-shell nanowires will find use in photochemical and photo-electronic fields.

Dynamic Determination of Some Optical and Electrical Properties of Galena Natural Mineral: Potassium Ethyl Xanthate Solution Interface

This paper presents results concerning optical and electrical properties of galena natural mineral and of the interface layer formed between it and the potassium ethyl xanthate solution. The applied experimental method was differential optical reflectance spectroscopy over the UV–Vis/NIR spectral domain. Computations were made using the Kramers–Kronig formalism. Spectral dependencies of the electron loss functions, determined from the reflectance data obtained from the polished mineral surface, display van Hove singularities, leading to the determination of its valence band gap and electron plasma energy. Time dependent measurement of the spectral dispersion of the relative reflectance of the film formed at the interface, using the same computational formalism, leads to the dynamical determination of the spectral variation of its optical and electrical properties. We computed behaviors of the dielectric constant (dielectric permittivity), the dielectric loss function, refractive index and extinction coefficient, effective valence number and of the electron loss functions. The measurements tend to stabilize when the dynamic adsorption-desorption equilibrium is reached at the interface level.

Homogeneous cellulose thin films by regeneration of cellulose xanthate: properties and characterization

The preparation and characterization of cellulose thin films derived from cellulose xanthate is reported. The films are prepared by depositing alkaline aqueous solutions of cellulose xanthate onto silicon wafers, followed by a spin coating step. Depending on the xanthate concentration used for spin coating, films with 50 and 700 nm thickness are obtained. The cellulose xanthate is converted to cellulose by exposing the films to HCl vapors over a period of 20 min. The conversion is monitored by ATR-IR spectroscopy, which allows for tracking the rupture of C–S and C=S bonds during the regeneration process. The conversion is accompanied by a reduction of the film thickness of ca 40% due to the removal of the bulky xanthate group. The films feature a homogenous, but porous morphology as shown by atomic force microscopy. Further, the films were investigated towards their interaction with Bovine Serum Albumin (BSA) and fibrinogen by means of multi-parameter surface plasmon resonance spectroscopy. Similar as other cellulose thin films BSA adsorption is low while fibrinogen adsorbs to some extent at physiological pH (7.4).

Fe(Ⅲ) ions enhanced catalytic properties of (BiO)2CO3 nanowires and mechanism study for complete degradation of xanthate

The wire-like Fe3+-doped (BiO)2CO3 photocatalyst was synthesized by a hydrothermal method. The photocatalytic property of Fe3+-doped (BiO)2CO3 nanowires was evaluated through degradation of sodium isopropyl xanthate under UV–visible light irradiation. The as-prepared Fe3+-doped (BiO)2CO3 nanowires were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) in detail. The results of XRD showed that the crystallinity of (BiO)2CO3 nanowires decreased when Fe3+ ions were introduced into the solution system. XPS results illustrated that xanthate could be absorbed on the surface of Fe3+-doped (BiO)2CO3 nanowires to produce BiS bond at the beginning of the reaction, which could broaden the visible light absorption. FTIR spectra confirmed the formation of SO42− after photocatalytic decomposition of xanthate solution. The Fe3+-doped (BiO)2CO3 nanowires showed an enhanced photocatalytic activity for decomposition of xanthate due to the narrower band gap and larger BET surface area, comparing with pure (BiO)2CO3 nanowires. By the results of UV–vis spectra of the solution and FTIR spectra of recycled Fe3+-doped (BiO)2CO3, the xanthate was oxidized completely into CO2 and SO42−. The photocatalytic degradation process of xanthate followed a pseudo-second-order kinetics model. The mechanism of enhanced photocatalytic activity was proposed as well.

Mechanism of different particle sizes of quartz activated by metallic ion in butyl xanthate solution

To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution, six common ions (Pb2+, Cu2+, Fe3+, Fe2+, Mg2+ and Ca2+) were introduced as activators. The approaches of micro-flotation, adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation. The results show that Pb2+, Cu2+ and Fe3+ are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface. Average recoveries of fine particles (<37 μm) are greater than those of coarser particles (37−74 μm), suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate. From another perspective, addition of metallic ions (Pb2+, Cu2+ and Fe3+) renders zeta potentials move positively, and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently, which support a mechanism where they adsorb onto quartz surface, resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries.