Extraction Of Antimony Research Articles

A comparative study of two nanosubstrates for the on-line solid phase extraction of antimony by FI-HG-AAS

Nanoporous carbon (NPC) prepared from metal organic frameworks (MOFs) was studied to serve as a sorbent for preconcentrating Sb(III) at trace levels. The performance of NPC regarding sensitivity, enrichment factor, analytical throughput and recovery was compared with that of multiwalled carbon nanotubes functionalised with l-proline (pro-MWCNTs). In this study, Sb(III) was preconcentrated using both substrates using an on-line flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) system. A low molecular weight polyethylene was added to the sorbent material to fill the preconcentration columns to avoid nanoparticle aggregation. A comprehensive study of the type and concentration of the reaction media and the eluent was carried out to select the best substrate not only in terms of adsorption capacity but also considering potential interferent control. The study evidenced that for Sb(III) retention, phtalate buffers (1.0mM at pH=6) resulted the best alternative. Under optimal conditions, both substrates exhibited high adsorption capacities: 343mgSbg−1 NPC and 559mgSbg−1 pro-MWCNTs. The preconcentration factors reached were: 258 and 420 for NPC and pro-MWCNTs, respectively. The high adsorption capacity of both substrate allowed reaching detection limits (3σ) of 1.47 and 0.52ngL−1 for NPC and pro-MWCNTs, respectively when using a sorbent column containing only 1.0mg of sorbent. Precision, expressed as relative standard deviation (RSD) turned to be ~2% at the 0.1μgL−1 level (n=10) for both substrates. Trueness test for the entire analytical procedure was performed by means of the Standard Reference Material (SRM) NIST 1643e (Trace elements in water) and results were in good agreement with the certified values. The system was evaluated for quantitative determination of Sb(III) in different kind of waters. The method is simple and relatively cheap in comparison with other methodologies.

Effect of selected parameters on stibnite concentrates leaching by ozone

A novel leaching process for stibnite concentrates using ozone as oxidant has been studied in this paper. The main factors affecting the leaching rate such as leaching temperature, concentration of leaching agent, gas flow rate and liquid to solid ratio have been investigated comprehensively. In addition, the effect of ferric chloride and sodium chloride on antimony extraction has been studied. The results indicate that the leaching efficiency (%) of the antimony increases with the increase of those factors mentioned above. And the form that the antimony dissolves into solution is SbCln3−n, while the sulfur mainly retains in the residue in the form of sulfur element. The oxidation leaching of stibnite concentrates has achieved antimony recoveries in excess of 99% under the optimum experimental conditions after 5h of leaching.

How can we adapt to geological scarcity of antimony? Investigation of antimony's substitutability and of other measures to achieve a sustainable use

Antimony is an element that is applied in many useful applications for mankind. However, antimony resources are very scarce, when comparing the current extraction rates with the availability of antimony containing ores. From an inter-temporal sustainability perspective, current generations should not deprive future generations from extractable ores. The extraction rate of a mineral resource is defined sustainable, if such a rate can be sustained for 1000 years assuming the same consumption per capita in all countries of the world. To achieve a sustainable extraction of antimony, it is necessary to reduce the current extraction with 96% compared to the primary antimony extraction in 2010. We have investigated whether such an ambitious extraction reduction goal would be technically feasible, without losing any of the current services that are provided by antimony. Reduction of the use of primary antimony can be achieved through (a combination of) substitution, improved material efficiency and recycling. Because the potential of material efficiency and recycling are limited in the case of antimony, the focus is on substitution of antimony in its applications.The major application of antimony (more than 50%) is in flame retardants. It appears that about 95% of antimony in flame retardants can be replaced by other components or systems. Overall, the substitutability of antimony in all its applications is estimated at around 90%.The required additional extraction reduction needs to be realized by improved material efficiency and further recycling, especially from the remaining antimony containing flame retardants and from lead-alloys.

Ozonation leaching of a complex sulfidic antimony ore in hydrochloric acid solution

Selective dissolution of stibnite from a complex sulfidic antimony ore containing pyrite by ozonation leaching in hydrochloric acid solution has been studied in the paper. Effects of hydrochloric acid concentration, leaching time, temperature, gas (ozone and oxygen mixture) flow rate and liquid/solid ratio on antimony extraction and iron dissolution have been examined. The results show that the leaching efficiency (%) of antimony increases with the temperature (from 35°C to 65°C) and hydrochloric acid concentration (from 3.0mol/L to 4.5mol/L). In comparison, the iron dissolution remains constant in these ranges. In addition, it is noted that the decomposition of stibnite is easier than that of pyrite. High antimony extraction (94.3%) with low iron dissolution (2.3%) is achieved under the following leaching conditions: 4.5mol/L hydrochloric acid concentration, 2.0L/min gas flow rate and 8:1 of the L/S ratio, leaching for 4.0h at 65°C. These results reveal that ozonation leaching of the complex sulfidic antimony ore in hydrochloric acid solution is a promising technology.

Direct cyanidation and roasting combination of a semi-refractory massive sulfide ore

In this study, cyanidation experiments were carried out on a massive sulfide ore sample, whose grades of the precious metals gold and silver were found to be 4.2 g/t and 311.9 g/t, respectively. Other elements in the ore were arsenic with average grade of 1,751.6g/t; antimony, 619.7 g/t; zinc, 781.4 g/t; copper, 454.6 g/t; lead, 101.8 g/t; mercury, 324.3 g/t; and bismuth, 0.6 g/t. The first objective of test workfocused on determining the best conditions for extracting goldfrom the ore, ground to less than 75 microns. Different influential parameters such as particle size fraction, cyanide concentration, pH and leaching time were investigated. The optimum parameters were found to be particle size fraction of less than 25 microns, cyanide concentration of 2,000 mg/L, pH of 11 and cyanidation time of 24 hours. In these optimum conditions, the highest gold and silver leaching efficiencies were 76.88 and 59.63 percent, respectively. In addition, roasting as pretreatment at a temperature of 700°C over a period of two hours was evaluated. Cyanidation testing of the roasted ore in the optimum conditions found increases in the gold and silver leaching efficiencies to 85.97 and 67.57 percent, respectively. Moreover, antimony extraction rose to 43.10 percent, from 23.73 percent without roasting.

Synthesis and characterisation of nano-pore antimony imprinted polymer and its use in the extraction and determination of antimony in water and fruit juice samples

A solid phase extraction method using antimony ion imprinted polymer (IIP) sorbent combined with electrothermal atomic absorption spectrometry (ETAAS) was developed for the extraction and speciation of antimony. The sorbent has been synthesised in the presence of Sb(III) and ammonium pyrrolidine dithiocarbamate (APDC) using styrene as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linker. The imprinted Sb(III) ions were removed by leaching with HCl (50%v/v) and the polymer was characterised by FT-IR and scanning electron microscopy. The maximum sorption capacity of the IIP for Sb(III) ions was found to be 6.7mgg−1. With preconcentration of 60mL of sample, an enhancement factor of 232 and detection limit of 3.9ngL−1 was obtained. Total antimony was determined after the reduction of Sb(V) to Sb(III). The method was successfully applied to the determination of antimony species in water samples and total antimony in fruit juices.

Extraction of antimony and tantalum from aqueous fluoride solutions by n-octanol and tributyl phosphate

19F and 21Sb NMR spectroscopy and chemical analysis were used to study the composition and structure of fluoride complexes of antimony(V) and tantalum(V) in organic and aqueous phases in extraction by tributyl phosphate (TBP) and n-octanol. It is found that extraction from solutions containing a single element or both elements occurs via the hydrate-solvate mechanism. The possibility of separating tantalum(V) and antimony(V) by extraction from fluoride solutions is shown. The efficiency of tantalum(V) and antimony(V) separation by extraction from fluoride solutions is enhanced at a transition from TBP to n-octanol.

A cloud point extraction for spectrophotometric determination of ultra- trace antimony without chelating agent in environmental and biological samples

We report on a simple, sensitive and reliable method for the cloud point extraction of antimony (Sb) and its subsequent spectrophotometric detection. It is based on the color reaction of Sb (III) with iodide in acidic medium and subsequent micelle-mediated extraction of tetraiodoantimonate using a non-ionic surfactant in the absence of any chelating agent. The effects of reaction and extraction parameters were optimized. The calibration plot is linear in the range of 0.80–95 ng mL−1 of antimony in the sample solution, with a regression coefficient (r) of 0.9994 (for n = 9). The detection limit (at SNR = 3) is 0.23 ng mL−1, and the relative standard deviations at 10 and 70 ng mL−1 of antimony are 3.32 and 1.85 % (at n = 8), respectively. The method compared favorably to other methods and was applied to determine antimony in seawater, anti-leishmania drug (glucantime), and human serum.

K 0-RNAA used in determination of 129I in a mixed resin sample

A k 0-RNAA procedure was developed to determine 129I in a mixed resin sample. CH4 extraction and (NH4)2SO3 back-extraction were used to separate 129I in ashed samples. The 129I target sample for irradiation in the reactor was prepared by heating the (NH4)2SO3 back-extraction solution to reduce its volume and then to dry it in a quartz ampoule. No MgO and LiOH were needed during the target sample preparation. After irradiation, the nuclide 130I was purified by combining hydrated antimony pentoxide column and CH4 extraction separations. A k-factor was determined for the reaction of 127I (n, 2n) 126I and used for iodine chemical yield determination. The apparent 129I concentrations of five nuclear reaction interferences were calculated. The relative standard deviation of three 129I determinations was found to be 3.5 %. The 129I content in the analyzed resin was found to be 1.36 × 10−9 g/g (8.63 × 10−3 Bq/g) with a relative uncertainty of 9.1 %. The detection limit of 129I was calculated to be 7.4 × 10−13 g (4.7 × 10−6 Bq) in a k 0-RNAA of a blank sample.

Headspace single-drop microextraction with in situ stibine generation for the determination of antimony (III) and total antimony by electrothermal-atomic absorption spectrometry

A headspace-single drop microextraction method combined with electrothermal atomic absorption spectrometry (ETAAS) is developed for the extraction and preconcentration of antimony(III) and total antimony into a Pd(II)-containing aqueous drop after hydride generation. Experimental variables such as hydrochloric acid and sodium tetrahydroborate concentrations, sample volume, Pd(II) concentration in the acceptor phase and microextraction time were optimized. A 26-2 IV factorial fractional design was initially used for screening the effect of the variables, followed by an univariate approach. The method showed a great freedom from interferences caused by hydride-forming elements and transition metals. The detection limit of Sb(III) was 25 pg mL−1. A preconcentration factor of 176 is achieved in 3 min. The repeatability, expressed as relative standard deviation, was 4.7%. The method was validated against two certified reference materials (NWRI-TM 27.2 and NIST 2711) and applied to the determination of Sb(III) and total Sb in waters.

Determination of Trace Elements in Arsenic and Antimony Minerals by Atomic Absorption Spectrometry and k0-Instrumental Neutron Activation Analysis After Removal of As and Sb

The content of trace elements in arsenic and antimony minerals from the Allchar mine, Macedonia, was determined by electrothermal atomic absorption spectrometry (ETAAS) and k0-instrumental neutron activation analysis (k0-INAA) after removal of arsenic and antimony. Their direct determination by ETAAS or k0-INAA in arsenic (realgar and orpiment) and antimony (stibnite) minerals is limited by strong matrix interferences from As and Sb. Successful elimination of both elements was realized by the extraction of their iodide complexes into toluene. It was found that the optimal conditions were triple extraction of arsenic into toluene from 6 mol·L−1 HCl with addition of KI. Triple extraction of antimony was most successful in the system 4.5 mol·L−1 H2SO4 and KI into toluene. In both cases, trace elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were then detected in the aqueous phase by ETAAS. The proposed procedures with ETAAS were checked by the method of standard additions and Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn determined in realgar, orpiment and stibnite. Using k0-INAA the trace elements Ba, Ce, Co, Cr, Cs, Fe, Hg, Sc, Tb, Th, U and Zn in realgar and orpiment were determined before and after As and Sb removal from the same aliquot of sample. The removal of both elements with KI into toluene was higher than 99.8% and no losses of trace elements were observed.

Flow-Injection Determination of Trace Antimony in Natural Waters with Extraction–Chromatographic Preconcentration

A procedure was developed for the flow-injection spectrophotometric determination of trace antimony in natural waters. The flow extraction preconcentration step involved the extraction of antimony(V) complex associates with basic dyes in an extraction–chromatographic column and the chromatomembrane separation of the extract from the aqueous phase. The detection limit was 1 μg/L for a 20-mL sample using a (1 : 5) methyl isobutyl ketone–carbon tetrachloride mixture as an extractant.

Extraction of antimony by a copper chloride extractant

Acorga CLX50, a product of Imperial Chemical Industries, is an extractant for cupric chloride. It also extracts a minor amount of antimony as an impurity during extraction of copper from chloride solutions. Behaviors of antimony extraction by CLX50 are investigated in this study. Stability of various antimony species is examined through establishment of Eh–pH and Eh–log[Cl −] diagrams. Slope analysis reveals that two moles of CLX50 react with one mole of antimony species. Acidity affects the antimony extraction differently at different acidity ranges, due to different reactions involved in the extraction. Effect of chloride ion on extraction of antimony and the linear relationship between copper extraction and antimony extraction are explained quantitatively.

Matrix Digestion of Soil and Sediment Samples for Extraction of Lead, Cadmium and Antimony and Their Direct Determination by Inductively Coupled Plasma-Mass Spectrometry and Atomic Emission Spectrometry

An environmentally friendly and simple method has been developed for complete digestion of lead, cadmium and antimony from soil samples using a magnesium nitrate assisted dry ashing procedure. Statistical data for a series of experiments with standard reference materials are presented, and precision values are found to be comparable for inductively coupled plasma-mass spectrometry and for inductively coupled plasma-atomic emission spectrometry. From a single digest solution all analytes are quantified without involving any pre-concentration routes. Inter-method comparison of inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) shows that the probability of the results being different is less than 99%.

Selective liquid-liquid extraction of antimony(III) from hydrochloric acid media by N-n-octylaniline in xylene

N-n-Octylaniline in xylene was used for the extraction separation of antimony( III) from hydrochloric acid media. Antimony(III) was extracted quantitatively with 10 mL4%N-n-octylaniline in xylene. It was stripped from the organic phase with 0.5 M ammonia and estimated photometrically by the iodide method. The effect of metal ion, acid, reagent concentration and various foreign ions was investigated. The method affords binary and ternary separation of antimony(III) from tellurium(IV), selenium( IV), lead(II) bismuth(III), tin(IV), germanium(IV), copper(II), gold(III), iron(III) and zinc(II). The method is applicable for the analysis of synthetic mixtures alloys and semiconductor thin films. It is fast, accurate and precise.

On-line determination of antimony(III) and antimony(V) in liver tissue and whole blood by flow injection – hydride generation – atomic absorption spectrometry

A new analytical procedure for the speciation of antimony in liver tissues is presented here. For this purpose, a flow injection system has been developed for the treatment of samples and the determination of antimony by hydride generation – atomic absorption spectrometry. The method involves the sequential and the on-line extraction of antimony(III) and antimony(V) from solid lyophilized blood and hamsters liver tissues, with 1.5 mol l −1 acetic acid and 0.5 mol l −1 sulfuric acid for Sb(III) and Sb(V), respectively. Reduction of Sb(V) to Sb(III) for stibine generation is effected by the on-line pre-reduction with l-cysteine. The linear ranges were 2.5–20 and 1.0–25 μg l −1 of Sb(III) and Sb(V), respectively. The detection limits (3 σ) were 1.0 μg l −1 for Sb(III) and 0.5 μg l −1 for Sb(V). The relative standard deviation values for fifteen independent measurements were 2.1 and 1.8% for Sb(III) and Sb(V), respectively. The recovery studies performed with samples of cattle liver provided results from 98 to 100% for Sb(III) and from 100 to 103% for Sb(V) for samples spiked with single species. For samples spiked with both Sb(III) and Sb(V), the recovery varied from 97 to 103% for Sb(III) and from 101 to 103% for Sb(V).

Biotechnology of Concentrate and Antimony Ore Processing

The results are presented for using microorganisms for mercury and antimony separation and extraction of oxidized antimony minerals. The problems on technology of direct processing of gold-antimony concentrates by pentachlorous antimony chlorides are considered. The perspective is shown for leaching antimony by alkaline solution of sulfate-reducing bacteria. The transformation of antimony sulfide into commodity concentrate of antimony trioxide by Thiobacillus ferrooxidans is demonstrated.

Solvent Extraction of Antimony(V) as Hexachloroantimonate(V) with Quaternary Ammonium Ions

Solvent Extraction of Antimony(V) as Hexachloroantimonate(V) with Quaternary Ammonium Ions

Solvent extraction separation of antimony(III) and bismuth(III) with bis(2,4,4-trimethylpentyl) monothiophosphinic acid (Cyanex 302)

Abstract Solvent extraction separation of antimony(III) and bismuth(III) was carried out from aqueous acidic solutions with Cyanex 302 in toluene. Quantitative extraction of antimony(III) was observed in the acidic range of 0.1–1.0 M H 2 SO 4 and 0.1–2.0 M HCl with 8.5×10 −2 M Cyanex 302 in toluene, whereas that of bismuth(III) was observed in the acidic range of 0.01–0.1 M HNO 3 and 0.01–0.1 M HCl with 1×10 −2 M Cyanex 302 in toluene. Antimony(III) from the organic phase was stripped with 8.5 M H 2 SO 4 and determined spectrophotometrically by the iodide method at 425 nm. Bismuth(III) from the organic phase was stripped with 2 M HNO 3 and determined spectrophotometrically by the thiourea method at 470 nm. The optimum extraction conditions were evaluated by a critical study of acidity, extractant concentration, period of equilibrium and effect of diluents. Separation of bismuth(III) and antimony(III) from one another in varying ratios of 1:1, 1:2, 1:4, 2:1 and 5:1 and multicomponent mixtures of commonly associated metals was found to be possible by this method. It was successfully applied for analysis of antimony and bismuth in real samples.

Separation of antimony(III) with iodide and dithizone by sorption on polyurethane foam from sulphuric acid medium for its spectrophotometric determination in glasses

A method for quantitative separation of antimony(III) by sorption on polyether based polyurethane foam and its spectrophotometric determination has been described. The method involves formation of a pink—red complex of antimony(III) with iodide (0.045 M) and dithizone (2.3 × 10 −5 M) in 0.25–0.75 M H 2SO 4 medium, sorption of the complex on polyurethane foam (within 45 min) at room temperature followed by its elution with acidified acetone (acetone containing 0.008% H 2SO 4) and spectrophotometric measurement at 507.2 nm (ϵ = 2.56 × 10 4 l mol cm). The method obeys Beer's law from 0.1 to 6.0 μg antimony(III). Tolerance limits of other ions are Co (100 μg), Ni (100 μg), Fe (10 μg), Cu (0.5 μg), Sn (20 μg), Zn (100 μg), As (100 μg), Mn (200 μg), Pb (50 μg), Ti (100 μg), V (50 μg), etc. Interference by iron and copper have been eliminated by treating with KOH prior to the extraction of antimony. The method has been standardized with glass samples spiked with known amounts of antimony and applied to the determination of antimony in various glasses.