Sm-Nd Geochronology,REE and C and O Isotope Study of Calcites and Stibnites from Banian Antimony Deposit

The Banian sediment-hosted antimony deposit is a medium-scale deposit located in the Dushan County,South Guizhou,China.Calcite as the dominant gangue mineral can be divided into two types: white and pink,the later is more intimate with mineralization.It is interesting that the REE characteristics are

A New Approach to Explaining the Oscillatory Oxidation of Arsenites, Stibnites and Vismutinites Using Magnetic Method

Magnetic and relativistic effects in uranium catalysts, the movement of charged particles under the effect of a uniform electric field and uniform magnetic field were studied in the paper. We have considered various mechanisms oscillating reactions （Models Jabotinsky-Korzukhina, Brusselator, Oregonator and Advanced Oregonator）. The mechanisms of the motion of charged particles under the influence of an electric field and a uniform magnetic field were proposed.

Metallogenesis of the Baidi Au-Sb deposit, southwest Guizhou Province, China: mineralogical and geochemical evidence from sulfur-bearing minerals

The Baidi Au-Sb deposit, which contains 8 t of Au and 10,979 Mt of Sb, is a typical and rare paragenetic deposit located in southwestern Guizhou Province, China.Previous studies have focused on individual ores, but have not combined them to identify their paragenetic mechanism or metallogenic regularity. Therefore, we used field investigations, microscopic observations, and in situ analyses to identify the spatial distribution, mineral paragenesis, compositional evolution, and metallogenic material sources of the ore bodies. We also determined the Au and Sb paragenetic characteristics and the metallogenesis of the deposit. The main Au-bearing minerals in the deposit were early(Apy1–2) and late(Apy3) stage arsenopyrites, as well as pre-mineralization(Py1), mineralization(Py2–5), and late mineralization(Py6–7) stage pyrites. The main Sb-bearing minerals were stibnite(Snt), skinnerite, bournonite,and valentinite. The minerals formed in the order of Py1,Py2–3 + Apy1, Py4–5 + Apy2, Snt, and Py6–7 + Apy3.The δ34S values of the arsenopyrites and pyrites ranged from-5 to 5‰, while those of stibnite were mostly less than-5‰ in the later mineralization stages. Sulfur was provided by deep magmatic hydrothermal fluids, but sedimentary sulfur was added in the later stages. Moreover,the trace elemental contents fluctuated and eventually became similar to those of the sedimentary strata. By comprehensively considering the ores along with the geological characteristics of the deposit, we determined that deep magma provided the Au during ore formation. Later tectonic changes provided Sb from the sedimentary strata,which precipitated along fault expansion areas and produced Au and Sb paragenesis.

Trace element compositions of pyrite and stibnite:implications for the genesis of antimony mineralization in the Yangla Cu skarn deposit,Northwestern Yunnan,China

The Yangla Cu skarn deposit is located in the central part of the Jinshajiang Suture Zone,southwest China,with a total reserve of 150 Mt Cu@1.03%.The newly discovered antimony orebodies at the depth of Yangla are strictly controlled by the stratum,structure,and lithology,which are lenticular and vein-like within the marble fracture zone,which can provide a window into multistage miner-alization and ore genesis at Yangla.Mineralization can be divided into three types,Cu–Pb–Zn(skarn)pyrite,galena,and sphalerite,Cu(porphyry)chalcopyrite and pyrite,and Sb(hydrothermal)stibnite and pyrite.The mineral assem-blages were stibnite+pyrite+calcite+quartz±minor scheelite in antimony ores.This study presents quantitative measurements of the trace element compositions of pyrite and stibnite from the Yangla antimony ores.Analysis of pyrite with electron probe microanalysis(EPMA)showed enrichment in Co,Ni,Sb,As,and Mo,and deficit in its S and Fe contents when compared to the stoichiometric con-centrations of S and Fe in pyrite.The Sb-related pyrite may belong to sedimentary-reworked genesis and may be modi-fied by hydrothermalfluids,thereby presenting a certain dif-ference(i.e.,crystal morphology,texture,and chemical com-position)compared to the skarn and porphyry Cu-related pyrite in the Yangla Cu skarn deposit.Analysis of stibnite with EPMA and inductively coupled plasma-mass spectrom-etry showed enrichment in As,Pb,Sn,Pb,Cu,and Zn,and presented much higher Sb contents and slightly lower S con-tents when compared to the stoichiometric concentrations of Sb and S in stibnite.Statistical analysis of the stibnite trace elements showed correlations for the elemental pairs Cu–Pb,As–Sb,and Sn–Pb,and the coupled substitution equations Sb^(3+)↔Cu^(+)+Pb^(2+),Sb^(3+)↔As^(3+),and Sn^(2+)↔Pb^(2+)may be the major factors governed the incorporating Cu,Pb,As and Sn within the stibnite.Moreover,this study preliminary shows that the antimony mineralization may belong to a car-bonate replacement hydrothermal genesis at Yangla.

Gold and antimony metallogenic relations and ore-forming process of Qinglong Sb(Au) deposit in Youjiang basin, SW China: Sulfide trace elements and sulfur isotopes

In the northwestern margin of the Youjiang basin(NWYB)in SW China,many Carlin-like gold deposits are highly antimony(Sb)-rich,and many vein-type Sb deposits contain much Au.These deposits have similar ages,host rocks,ore-forming temperatures,ore-related alterations and ore mineral assemblages,but the Au and Sb metallogenic relations and their ore-forming process remain enigmatic.Here we investigate the large Qinglong Sb deposit in the NWYB,which has extensive sub-economic Au mineralization,and present a new metallogenic model based on in-situ trace elements(EPMA and LA-ICP-MS)and sulfur isotopes(NanoSIMS and fs-LA-MC-ICPMS)of the ore sulfides.At Qinglong,economic Sb ores contain coarse-grained stibnite,jasperoid quartz and fluorite,whilst the sub-economic Au–Sb ores comprise dominantly veined quartz,arsenian pyrite and fine-grained stibnite.Three generations of ore-related pyrite(Py1,Py2 and Py3)and two generations of stibnite(Stb1 and Stb2)are identified based on their texture,chemistry,and sulfur isotopes.The pre-ore Py1 is characterized by the lower ore element(Au,As,Sb,Cu and Ag)contents(mostly below the LA-ICP-MS detection limit)and Co/Ni ratios(average 0.31)than the ore-stage pyrites(Py2 and Py3),implying a sedimentary/diagenetic origin.The Py2 and Py3 have elevated ore element abundance(maximum As=6500 ppm,Au=22 ppm,Sb=6300 ppm,Cu=951 ppm,Ag=77 ppm)and Co/Ni ratios(average 1.84),and have positive As vs.Au–Sb–Cu–Ag correlations.Early-ore Stb1 has lower As(0.12–0.30 wt.%)than late-ore Stb2(0.91–1.20 wt.%).These features show that the progressive As enrichment in ore sulfides is accompanied by increasing Au,Sb,Cu and Ag with the hydrothermal evolution,thereby making As a good proxy for Au.As-rich,As-poor and As-free zones are identified via NanoSIMS mapping of the Au-bearing pyrite.The As-rich zones in the Qinglong Au-bearing pyrites(Py2 and Py3)and ore stibnites(Stb1 and Stb2)have narrowδ^(34)SH_(2)S ranges(-8.9‰to +4.1‰,average-3.1‰)and-2.9‰to +6.9‰,average + 1.3‰),respectively,indicating that the Au-rich and Sb-rich fluids may have had the same sulfur source.Published in-situ sulfur isotopic data of pyrite As-rich zones from other Carlin-like Au deposits(Shuiyindong,Taipingdong,Nayang,Getang and Lianhuashan)in the NWYB have similar ore-fluidδSH_(2)S values(-4.5‰to +6.7‰,average-0.6‰)to those of Qinglong.Therefore,we infer that the sulfur of both Au and Sb mineralization was derived from the same magmatic-related source(0±5‰)in the NWYB.Moreover,the core of pyrites(Py1)has variable S isotope fractionation(-18.9‰to +18.1‰,mostly +3‰to +12‰),suggesting that the higher-^(34)S H_(2)S was produced by bacterial sulfate reduction(BSR).The hydrothermal pyrite(Py2 and Py3)δ^(34)S values gradually decrease with increasing As concentrations,and ultimately,within the restricted range(-5‰to +5‰)in As-rich zones.This variation implies that the As-rich pyrite was formed through ongoing interactions of the magmatic-hydrothermal fluid with pre-existing sedimentary pyrites,causing the progressive decreasing δ^(34)S values with As content increase,Hence,the fluid/mineral interaction may have generated the observed variation in δ^(34)S and As contents.Overall,comparing the Au and Sb deposits in the NWYB,we favor a magmatic-related source for the Au–Sb–As-rich fluids,but the Au-and Sb-ore fluids were likely evolved at separate stages in the ore-forming system.

One-step electrochemical reduction of stibnite concentrate in molten borax

In this study,antimony production from a stibnite concentrate(Sb2S3)was performed in one step using a molten salt electrolysis method and borax as an electrolyte.Electrochemical reduction of the stibnite concentrate was performed at 800℃under galvanostatic conditions and explained in detail by the reactions and intermediate compounds formed in the borax.The effects of current density(100 800 mA cm^-2)and electrolysis time(10 40 min)on cathodic current efficiency and antimony yields were systematically investigated.During the highest current efficiency,which was obtained at 600 mA cm^-2,direct metal production was possible with 62%cathodic current efficiency and approximately 6 kWh/kg energy consumption.At the end of the 40-min electrolysis duration at 600 mA cm^-2 current density,antimony reduction reached 30.7 g and 99%of the antimony fed to the cell was obtained as metal.

Mineralogy,sulfur isotopes and infrared microthermometric study of the Leishan-Rongjiang antimony ore field,SW China

The Leishan-Rongjiang antimony ore field(LAOF) is in a unique geotectonic location in the uplift between the Youjiang and Xiangzhong basins.This paper focuses on two representative deposits in the LAOF:the Bameng and Peize antimony(Sb) deposits.We analyzed fluid inclusions(FIs) in stibnite and coexisting quartz,as well as the sulfur isotopic composition of stibnite,to better understand the nature of the ore-forming fluid and the metallogenic process.The FIs data from samples of the stibnite and coexisting quartz indicate that the ore-forming fluids were characterized by low-temperature(150-210 ℃),low-salinity(1.5 wt%-6.0 wt%NaCl equiv.),and low-density(0.872-0.961 g/cm^3).The δ^(34)S values of stibnite(-8.21‰ to 3.76‰,average =-6.30‰)fall in between the sulfur isotopic compositions of the mantle and of biogenic sulfur in sedimentary rocks.However,the δ^(34)S_(∑s) values(-4.41 ‰ to +0.04‰,average =-2.49‰) of the ore-forming fluids are generally closer to the sulfur isotopic composition of the mantle source,indicating that the sulfur in the LAOF was mainly sourced from the mantle,but with possible involvement of biogenic sulfur.In addition,FIs petrography and ore deposit geology show that fluid boiling resulted from an abrupt decrease in pressure,which may have triggered the precipitation of stibnite.We conclude that low-temperature,dilute hydrothermal fluids with mixed origins migrated along the regional fault and interacted with the wall rock,extracting the ore-forming materials.Then,the oreforming fluids were injected into the fault fracture zones.

THE PULP ELECTROCHEMISTRY OF FLOTATION SEPARATION FOR STIBNITE-ARSENOPYRITE BULK CONCENTRATE

In the thermodynamics, for flotation separation of the SbAs bulk concentrate system there is no potential extent using butyl xanthate as collector. However in the kinetics, there exists 150 mV in reducing potential of butyl dixanthogen on the surface of stibnite and arsenopyrite. In this paper, their reducing kinetic difference of electrochemistry was confirmed by pure mineral flotation under controlled potential, the artificial SbAs bulk concentrate flotation separation and UVspectrophotometic analysis. The electrochemical separation of SbAs bulk concentrate has been carried out. qualified concentrate has been obtained. Sbconcentrate contains Sb 4944 %, As 044 %, Sbrecovery is 8783 % and Asconcentrate contains As 1096 %, Asrecovery is 9466 %.

Anodic process of stibnite in slurry electrolysis:The direct collision oxidation

Mineral oxidation leaching in the anode area is the key step in slurry electrolysis.By adopting the slow linear potential scanning method during slurry electrolysis,this study investigated the steady-state polarization curve of a pure stibnite mineral on a graphite anode.In addition,the influence of the mineral particle size,liquid–solid ratio,stirring speed,and temperature on the collision oxidation of the mineral with the anode was studied.Based on the different oxidation reactions,the potential range can be divided into three intervals:the low-potential interval with a potential lower than 0.75 V,an intermediatepotential interval with a potential within 0.75–1.2 V,and a high-potential interval with a potential higher than 1.2 V.The collision oxidation of the mineral with the anode occurred in all three intervals.The oxidation of Sb(III)also appeared in the intermediate-and high-potential intervals,and chlorine evolution occurred in the high-potential interval.Therefore,the low-potential interval was determined to be a suitable potential interval for the slurry electrolysis process.In the low-potential interval,the particle size,liquid–solid ratio,and stirring speed had little effect on the oxidation rate of the minerals.As the temperature increased,the stibnite oxidation rate and exchange current density increased.Overall,the direct collision oxidation rate of stibnite was relatively low and the current densities under all the investigated conditions were lower than 0.4 mA·cm^(-2.This indicates that it is difficult to realize industrial production while relying solely on this process.

Mechanism of stibnite volatilization at high temperature

The volatilization of stibnite(Sb2S3) in nitrogen from 700 to 1000 °C was investigated by using thermogravimetric analysis. The results indicate that in inert atmosphere, stibnite can be volatilized most efficiently as Sb2S3(g) at a linear rate below850 °C, with activation energy of 137.18 k J/mol, and the reaction rate constant can be expressed as k=206901exp(-16.5/T). Stibnite can be decomposed into Sb and sulfur at temperature above 850 °C in a nitrogen atmosphere. However, in the presence of oxygen,stibnite is oxidized into Sb and SO2 gas at high temperature. Otherwise, Sb is oxidized quickly into antimony oxides such as Sb2O3 and Sb O2, while Sb2O3 can be volatilized efficiently at high temperature.

辉锑矿电氯化浸出与锑的同时电积

直接湿法生产锑白的研究推动了湿法炼锑工艺的发展,近年防腐蚀材料的进展使湿法冶金设备有较大突破,因而国内已报道过几种酸性湿法炼锑。本文报道在同一设备完成锑矿浸出与电积的一步炼锑法新工艺。

Metal Extraction Process for High Grade Stibnite of Kharan (Balochistan Pakistan)

A rapid and simple process has been developed for the recovery of antimony metal from stibnite ore of Kharan area (Balochistan) of Pakistan. The ore was characterized by X-ray diffraction (XRD) technique and found to contain 66% stibnite i.e. antimony sulfide (Sb2S3). The process parameters for the extraction of antimony were optimized on laboratory scale by varying reaction temperature from 900℃ - 1000℃, reaction time from 20 - 80 minutes and flux concentration was varied from 5 - 25 weight percent of the reaction mixture. The metal thus recovered with optimum conditions was evaluated by X-ray fluorescence (XRF) technique and was found to be more than 94% pure. The recovery yield calculated on the basis of stibnite present in the ore was 98.52%.

CHEMICAL PROPERTIES OF AMINO-CARBOXYLMETHYL CELLULOSE AND ITS DEPRESSING MECHANISMS ON STIBNITE

This paper presents a study on the chemical properties of amino-carboxylmethyl cellulose (ACMC) and the mechanisms of the reac-tion of ACMC ivith copper ions and the depression of ACMC on CuSO4-ac-tivated stibnite. The results of XPS and IR analyses show that after CMC is treated by aqueous ammonia , amino-carboxyl groups form in CMC molecules by H-bonding action ivhich can complex selectively ivith copper ions to form copper-amino-carboxylmethyl cellulose. On the surface of CuSO4-activated stibnite, ACMC is also able to complex strongly with cop-per ions and forms a strong hydrophilic depression film. Because there are the obvious difference of reactions between ACMC ivith Cu2+ and ACMC ivith Hg2+ , the separation of cinnabar from stibnite is successfully realized using ACMC as depressant and CuSO4 as activator.

Reduction of Stibnite at Moderate Temperature

Reduction of stibnite with hydrogen in the presence of calcium oxide has been experimentally inves- tigated at moderate temperature. The results reveal that the effluent generated in the reduction pro- cess contains much less air-polluting substance H_2S, and that the reaction activation energy is 63. 3 kJ/mol. The form of antimony changes considerably when the reaction temperature varies.

Origin of ore-forming fluids in Qinggouzi stibnite deposit,NE China:Constraints from fluid inclusions and H-O-S isotopes

The Qinggouzi stibnite deposit is located in Huashan Town,Jilin Province,in the northeastern margin of North China Craton(NCC).It is controlled by fault structures,hosted within structurally controlled felsic dykes,predominantly surrounded by phyllite,schist and quartzite.This study presents the results of fluid inclusions studies,intending to determine the source of the fluid responsible for ore-formation,hence exploring its metallogenesis.The aqueous biphase inclusions are identified in the stibnite-bearing quartz veins of the deposit.Moreover,aqueous biphase inclusions are further classified into(1)biphase liquid-rich inclusions(1 a)and(2)biphase gas-rich inclusions(1 b)depending upon liquid to gas ratio trapped within the fluid inclusions.Homogenization temperatures for(1 a)and(1 b)range between 114.8℃to 422℃and 128.3℃to 267.5℃,respectively.1 a and 1 b have salinities of 0.18%to 16.14%NaCleqv and 1.22%to 12.88%NaCleqv,and density range from 0.43 to 1.02 g/cm^(3) and 0.81 to 0.98 g/cm^(3),respectively.Sulfur isotopic analysis indicatesδ34SV-CDT from 4.4×10-3 to 6.5×10^(-3),with an average of 5.2×10^(-3),whereas H isotopes values onδDV-SMOW standard are-100.8×10^(-3) and-107.5×10^(-3),while O isotopes data onδ18OV-SMOW standard range between 20.1×10^(-3) and 20.4×10-3.Fluid inclusions study,combining with sulfur and H-O isotopic data reveal that the ore-forming fluids originated from deep source and were subsequently contaminated by meteoric water.Hydrostatic pressure calculation shows that the minimum and maximum pressures are 11.65 and 42.33 MPa,and relevant depths of deposit are estimated to be 1.16 and 4.23 km.Finally,we inferred that Qinggouzi stibnite deposit is a medium-low temperature,low salinity hydrothermal deposit,which is formed by deep source and later contaminated by meteoric water,and is classified as epizonal deposit in terms of orogenic series.

Antimony transformation and mobilization from stibnite by an antimonite oxidizing bacterium Bosea sp. AS-1

Soils and waters are heavily contaminated by antimony in Xikuangshan(XKS)mine area.It is widely accepted that oxidative dissolution of sulfide minerals and aqueous dissolution are the most prevalent geochemical mechanisms for the release of Sb to the environment.Bosea sp.AS-1 is an antimonite-oxidizer isolated from the mine slag in Xikuangshan Sb mine.Whole genome sequencing revealed the presence of multiple sulfur-oxidizing genes,antimony(Sb)metabolism genes and carbon fixation genes in AS-1 s genome.We therefore hypothesized that under oxic conditions,AS-1 could mediate the oxidation of sulfide and Sb(Ⅲ)in stibnite(Sb_(2)S_(3))and lead to the release of Sb.Indeed,strain AS-1 was discovered as an autotrophic Sb(Ⅲ)-oxidizer.Antimony mobilization studies conducted with strain AS-1showed significantly enhanced mobilization of Sb,and complete oxidation of released Sb and sulfur to Sb(V)and sulfate.In addition,AS-1 induced a faster release of Sb under heterotrophic condition,and new acicular minerals might form.These findings support the hypothesis that microorganisms play an important role in the mobilization and transformation of Sb in XKS mine area and may contribute to our further understanding of the Sb biogeochemical redox cycle in natural environment.

Depositing natural stibnite on 3D TiO_(2) nanotube array networks as high-performance thin-film anode for lithium-ion batteries

Three-dimensional(3D) thin-film electrodes are promising solution to the volume change of active materials in lithium-ion batteries.As a conductive current collector,the 3D TiO_(2) nanotube array networks(TNAs) have a one-dimensional stable electronic conductive path and increase the adhesion between the current collector and raw material,thereby improving the cycle stability of active materials.In this study,a novel 3D-TNAs@Sb_(2)S_(3) anode was fabricated by directly depositing natural stibnite onto3D TNAs.The adhesion of Sb_(2)S_(3) particles to the substrate was enhanced due to the large surface area provided by 3D-TNAs.Moreover,the porous layered structure composed of Sb_(2)S_(3) nanoparticles relieved the stress generated during lithiation and adapted to the volume change of Sb_(2)S_(3) during cycling.Therefore,the resulting composite anode exhibits high cycle and rate performance,reaching0.36 mAh·cm^(-2) after 80 cycles at the galvanostatic rate of1 mA·cm^(-2),with high coulombic efficiency of 98%.

FRACTIONATION OF SULFUR ISOTOPES IN CRYSTALS OF STIBNITE AND PYRITE

While the fractionation of sulfur isotopes is known to occur between neighboring deposits of two different minerals containing sulfur, little knowledge exists as regards such fractionation in a certain single sulfur-containing mineral. Recently