The Saxi tungsten deposit,located in the Laojunshan ore district of southeastern Yunnan Province,is a significant W-polymetallic deposit.The origins of tungstenbearing pegmatite dikes and quartz vein mineralization in...The Saxi tungsten deposit,located in the Laojunshan ore district of southeastern Yunnan Province,is a significant W-polymetallic deposit.The origins of tungstenbearing pegmatite dikes and quartz vein mineralization in the Saxi deposit remain poorly understood.This study employs in situ U-Pb dating of apatite from the altered granite,along with trace element and S-Pb isotopic analysis of arsenopyrite,to investigate the timing,source of ore-forming fluids and the mechanisms of tungsten enrichment.The apatite in the altered granite yields a U-Pb age of 147.0±4.0 Ma,indicating magmatic activity during the Early Cretaceous.Three generations of arsenopyrite(Apy)are identified:Apy-1 in the altered granite,Apy-2 in the pegmatite dikes and Apy-3 in the quartz veins.The S/Fe ratios for Apy-1,Apy-2 and Apy-3 range from 0.98 to 1.09,0.89 to 0.92 and 0.86 to 1.02,respectively(average 0.97),suggesting a magmatic-hydrothermal origin.Sulfur isotope values(δ^(34)S=4.29‰-8.11‰)indicate that it was likely sourced from deep magmatic-hydrothermal fluids.Lead isotopic compositions of arsenopyrite suggest that the granitic parental magma is derived from the upper crust.These findings point to a magmatic-hydrothermal origin for the vein-type tungsten mineralization,linked to a concealed magmatichydrothermal system in the Early Cretaceous.展开更多
Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mec...Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.展开更多
Arsenopyrite was artificially added into the thiosulfate leaching solution to clarify the role of arsenopyrite on the thiosulfate leaching of gold.The effect of arsenopyrite on the thiosulfate leaching of gold was stu...Arsenopyrite was artificially added into the thiosulfate leaching solution to clarify the role of arsenopyrite on the thiosulfate leaching of gold.The effect of arsenopyrite on the thiosulfate leaching of gold was studied by the thermodynamic calculation,mineral dissolution test,leaching test and XPS analysis.The results show that the thiosulfate consumption slightly increases with increasing the concentration of arsenopyrite,but the gold dissolution is obviously hindered.This may mainly attribute to the catalytic effect of arsenopyrite on the thiosulfate decomposition and the formation of passivation layer on the gold foil surface.The passivation layer likely consists of Cu2S or Cu（S2O3）35-,element S,FeOOH and iron arsenate,which is deduced from the XPS analysis.However,the negative effect of arsenopyrite can be eliminated by adding additives.It is found that both additives of sodium carboxymethyl（CMC） and sodium phosphate（SHPP） can not only decrease the thiosulfate consumption but also improve the gold dissolution.展开更多
Lime(CaO)and sodium humate(NaHA)were used as the combined depressant for arsenopyrite pre-treated by CuSO_(4) and butyl xanthate.Micro-flotation tests show that the combined depressant CaO and NaHA achieved the select...Lime(CaO)and sodium humate(NaHA)were used as the combined depressant for arsenopyrite pre-treated by CuSO_(4) and butyl xanthate.Micro-flotation tests show that the combined depressant CaO and NaHA achieved the selective depression of arsenopyrite.Closed-circuit lab-scale test results indicate that the synergistic effect of CaO+NaHA achieved a satisfactory flotation separation of sphalerite and arsenopyrite,for which the Zn grade and recovery of Zn concentrate were 51.21%and 92.21%,respectively.Contact angle measurements,adsorption amount measurements and X-ray photoelectron spectroscopy analysis indicate that the dissolved calcium species(mainly as Ca(2+))were adsorbed on the mineral surfaces,thereby promoting NaHA adsorption.Moreover,the surface of the arsenopyrite absorbed more amount of calcium species and NaHA than that of the sphalerite,thereby accounting for the strong hydrophilic surface of arsenopyrite.The adsorption of NaHA on arsenopyrite was mainly chemical adsorption through its carboxyl groups and Ca atoms,whereas that on sphalerite surface was relatively weak.展开更多
A small molecular organic depressor glycerine-xanthate was synthesized. The effect of glycerine-xanthate on the flotation of sulfide minerals was investigated based on a function of pH value and concentration of glyce...A small molecular organic depressor glycerine-xanthate was synthesized. The effect of glycerine-xanthate on the flotation of sulfide minerals was investigated based on a function of pH value and concentration of glycerine-xanthate through flotation experiments in the presence and absence of Cu^2＋. The results show that glycerinee-xanthate has a strong dressing effect on marmatite at pH〉6 and on arsenopyrite in weak acid and base conditions with butyl-xanthate as collector. In the presence of glycerine -xanthate, marmatite is activated by addition of Cu^2＋, but arsenopyrite cannot be activated and remains unfloatable. So the selective separation can be achieved for two minerals. The depression of glycerine-xanthate on sulfide minerals was discussed based on the radical electronegative calculation and the theory of HSAB. Infrared spectrum shows that there are some -OH and-CSS-in glycedne-xanthate molecule, which competes with butyl-xanthate on the mineral surface. As a result of many hydrophilic groups in glycerine-xanthate, the surfaces of marmatite and arsenopyrite become hydrophilic, thus the flotation of marmatite and arsenopyrite is depressed. The collector is adsorbed preferentially on the surface of marmatite and it shows a better floatability in the presence of Cu^2＋, whereas, the surface of arsenopyrite absorbs glycerine-xanthate and the flotation of arsenopyrite is depressed by glycerine-xanthate.展开更多
Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collect...Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collector was investigated by flotation experiments,contact angle measurements,adsorption measurements,localized electrochemical impedance spectroscopy(LEIS)measurements,and X-ray photoelectron spectroscopy(XPS)analyses.The results showed that K_(2)FeO_(4)strongly depressed arsenopyrite in a pH range of 4−11,and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^(−4)mol/L K_(2)FeO_(4)and 5×10^(−5)mol/L PEX at pH 8 or 10.In the presence of K_(2)FeO_(4) and PEX,the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly.LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface.XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.展开更多
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...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 %.展开更多
The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated...The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated pyrite in high alkalinity and high Ca^(2+)system,whereas arsenopyrite was almost unaffected.In mineral mixtures tests,the recovery difference between pyrite and arsenopyrite after adding ammonium oxalate is more than 85%.After ammonium oxalate and ethyl xanthate treatment,the hydrophobicity of pyrite increased significantly,and the contact angle increased from 66.62°to 75.15°and then to 81.21°.After ammonium oxalate treatment,the amount of ethyl xanthate adsorption on the pyrite surface significantly increased and was much greater than that on the arsenopyrite surface.Zeta potential measurements showed that after activation by ammonium oxalate,there was a shift in the zeta potential of pyrite to more negative values by adding xanthate.X-ray photoelectron spectroscopy test showed that after ammonium oxalate treatment,the O 1s content on the surface of pyrite decreased from 44.03%to 26.18%,and the S 2p content increased from 14.01%to 27.26%,which confirmed that the ammonium oxalatetreated pyrite surface was more hydrophobic than the untreated surface.Therefore,ammonium oxalate may be used as a selective activator of pyrite in the lime system,which achieves an efficient flotation separation of S-As sulfide ores under high alkalinity and high Ca2+concentration conditions.展开更多
The galvanic interaction of arsenopyrite−magnetite in acidic culture medium was investigated by electrochemical measurements,X-ray photoelectron spectroscopy characterization and leaching experiments.The results indic...The galvanic interaction of arsenopyrite−magnetite in acidic culture medium was investigated by electrochemical measurements,X-ray photoelectron spectroscopy characterization and leaching experiments.The results indicated that the rest potential of magnetite was 321 mV,which was more anodic than 223 mV of arsenopyrite,and the galvanic current was 7.40μA,verifying the existence of the galvanic interaction between arsenopyrite and magnetite.The galvanic potential and polarization curves suggested that the redox behaviors of arsenopyrite dominated the overall galvanic interaction.The galvanic interaction enhanced the electrochemical dissolution of arsenopyrite with the generation of more oxidation products(S^(0),SO_(3)^(2−),SO_(4)^(2−)and AsO_(3)^(3−)) on arsenopyrite and an increase in the chemical reactivity of the surface.Leaching experiments of 6 days showed that the presence of magnetite improved the arsenic release from arsenopyrite by 30 mg/L,and further confirmed the enhanced oxidation of arsenopyrite when coupled with magnetite.展开更多
Understanding bacterial adsorption and the evolution of biofilms on arsenopyrite with different surface structures is of great signific-ance to clarifying the mechanism of microbe-mineral interfacial interactions and ...Understanding bacterial adsorption and the evolution of biofilms on arsenopyrite with different surface structures is of great signific-ance to clarifying the mechanism of microbe-mineral interfacial interactions and the production of acidic mine drainage impacting the environ-ment.In this study,the attachment of Sulfobacillus thermosulfidooxidans cells and subsequent biofilm formation on arsenopyrite with different surface structures in the presence of dissolved As(Ⅲ)was studied.Arsenopyrite slices with a specific surface were obtained by electrochemic-al corrosion at 0.26 V.The scanning electronic microscopy-energy dispersion spectra analyses indicated that the arsenopyrite surface deficient in sulfur and iron obtained by electrochemical treatment was not favorable for the initial adsorption of bacteria,and the addition of As(Ⅲ)in-hibited the adsorption of microbial cells.Epifluorescence microscopy showed that the number of cells attaching to the arsenopyrite surface in-creased with time;however,biofilm formation was delayed significantly when As(Ⅲ)was added.展开更多
Based on comprehensive analysis of the crystal structure, chemical and phase composition of natural arsenopyrite of the "Panimba" deposit (Krasnoyarsk region), an analytical expression for calculating the im...Based on comprehensive analysis of the crystal structure, chemical and phase composition of natural arsenopyrite of the "Panimba" deposit (Krasnoyarsk region), an analytical expression for calculating the impurity density in structure of minerals type of marcasite are received.展开更多
The thermal decomposition of pyrite, arsenopyrite and auriferous concentrates in the presence of sodium hydroxide was studied by using TG DTA and XRD methods. For the arsenopyrite mineral the reaction takes place at ...The thermal decomposition of pyrite, arsenopyrite and auriferous concentrates in the presence of sodium hydroxide was studied by using TG DTA and XRD methods. For the arsenopyrite mineral the reaction takes place at 200～350℃ with the formation of Na 2SO 4, Na 3AsO 4, FeSO 4, Fe 8As 10 O 23 and FeAs, and a large amount of FeAsS do not decompose at this temperature. When the temperature arrives at 800℃, the exothermic reaction takes place with the formation of Na 3AsO 4, Na 2SO 4, Fe 2O 3 and a little amount of As 4S 3. For the pyrite mineral the reaction takes place between 200～350℃ with the formation of Fe 2(SO 4) 3, Fe 3S 4, FeS, Na 2Fe(SO 4) 2 in addition to unreacted FeS 2 and NaOH. When the temperature arrives at 800℃, almost all the pyrite decomposes and the Fe 2O 3, Na 2SO 4, Fe(SO 4) 3 and a minor amount of Fe 1- x S are produced. The decomposition temperatures of arsenopyrite and pyrite get lower as their particle sizes are small. The results also indicated that with the addition of an appropriate amount of NaOH, nearly complete containment of arsenic and sulphur during the decomposition of auriferous concentrate may be possible.展开更多
The kinetics of the catalytical oxidation acid leaching of arsenopyrite is studied in the HNO<sub>3</sub>-H<sub>2</sub>SO<sub>4</sub>-O<sub>2</sub> aqueous system. In ad...The kinetics of the catalytical oxidation acid leaching of arsenopyrite is studied in the HNO<sub>3</sub>-H<sub>2</sub>SO<sub>4</sub>-O<sub>2</sub> aqueous system. In addition to the effect of reaction time on the extraction of arsenopyrite and distribution of products, the effects of operation factors and several additives on the reaction rate are also investigated. The experi mental results show that the oxidation rate is greatly dependent on nitric acid concentration, average radius of samples and acid concentration. The elemental sulphur produced does not interfere with the progress of the reacation process. It is found that a shrinking core model with chemical reaction controlling, which is expressed as 1-（1-α）<sup>1/3</sup>=kt, may be adopted to describe the kinetics results. The apparent activation energy is tested to be 23. 6 kJ/mol.展开更多
In this paper, the separation of arsenopyrite from chalcopyrite, pyrite, galena with organic depressants （guergum and sodium humic ） was discussed, and the functioning mechanism of those organic depressants was disc...In this paper, the separation of arsenopyrite from chalcopyrite, pyrite, galena with organic depressants （guergum and sodium humic ） was discussed, and the functioning mechanism of those organic depressants was discussed. The experimental results of monomineral flotation indicated that both guergum and sodium humic have depressing effect on arsenopyrite in the presence of ethyl xanthate. Guergum and sodium humic showed different depressing ability to pyrite, chalcopyrite and galena, and the higher the pH value in pulp, the stronger the depressing ability. Ultraviolet-Visible Spectrophotometric study showed that the adsorption layer of xanthate on surface of minerals had been desorhed by the two organic depressants, and the selective desorption of the collector layer was found from different minerals. The xanthate cover on minerals surface was set free when dosage of the organic depressants was high enough. For artificially-mixed minerals, the separation of arsenopyrite from other sulphides was successfully realized by controlling dosage of the organic depressants. And sodium humic had been concentrates in a commercial Lead-Zinc concentrator.展开更多
Arsenopyrite is one of very important and common auriferous minerals in endogenetic gold deposits. In seven gold deposits, the prospecting typomorphic characteristics of arsenopyrite, such as morphological typomorphis...Arsenopyrite is one of very important and common auriferous minerals in endogenetic gold deposits. In seven gold deposits, the prospecting typomorphic characteristics of arsenopyrite, such as morphological typomorphism, composition typomorphism, pyroelectricity typomorphism and so on, were established. The crystal form of arsenopyrite is simple, and the form symbols mainly are {101}, {120}, {210}, {140}, {230}, {012}, etc. The smaller grain and poor crystal form arsenopyrite indicates the better auriferous characteristics. The major elements (Fe, As and S) of gold-bearing arsenopyrite usually show Fe/As+S>0.5,As/S<1 which deviates from its theoretical value. The most important trace element is Au and next is Ag in arsenopyrite, and they often show the positive correlation. The pyroelectricity of arsenopyrite can reflect the mineralization epoch, and it also is related to the crystal form and granudarity.展开更多
Avoiding the formation of a passivation layer comprising intermediate products and secondary minerals is a principal challenge in preoxidizing arsenical gold ores.Due to the similar crystal,pyrite(Py) always coexists ...Avoiding the formation of a passivation layer comprising intermediate products and secondary minerals is a principal challenge in preoxidizing arsenical gold ores.Due to the similar crystal,pyrite(Py) always coexists with arsenopyrite(Ap) and effects the oxidation,although its mechanism needs to be improved.Therefore,this study focuses on a mixed leaching system involving Py and Ap.The effects of refactoring the passivation layer structure through Ap oxidation using Py under various pH conditions is systematically investigated.The role of Py in the formation and regulation of the Ap passivation layer is clarified using advanced characterization techniques.The study results indicate that Py decreased the pH,causing the ferric arsenate in the passivation layer of Ap oxidation to become soluble.Furthermore,the addition of Py decreased the jarosite content in the passivation layer.These reconstruction effects of Py on the passivation layer of the Ap surface considerably enhanced Ap oxidation.The highest level of arsenic dissolution(821.43 mg/L) was observed at the mass ratio of Py and Ap at 2(Py/Ap=2),representing an obvious increase compared to the control group(520.96 mg/L).This study focuses on the reconstruction of the passivation layer by Py,and further elucidates the role of Py in enhancing Ap oxidation during the pretreatment of arsenical gold ores,thereby advancing our understanding of the interaction rules between gold-bearing minerals of arsenical gold ores.展开更多
The distribution of gold in small acicular arsenopyrite of a pyrite-arsenopyrite association from Suzdal(Eastern Kazakhstan),Olympiada(Yenisei Ridge,Russia)and large pseudorhombic arsenopyrite crystals from Bazovskoe(...The distribution of gold in small acicular arsenopyrite of a pyrite-arsenopyrite association from Suzdal(Eastern Kazakhstan),Olympiada(Yenisei Ridge,Russia)and large pseudorhombic arsenopyrite crystals from Bazovskoe(Yakutia,Russia)orogenic-type deposits were investigated.On orogenic gold deposits in NE Asia,occurring mainly in black shales,two productive stages of ore deposition are distinguished,which correspond to two morphological varieties of arsenopyrite.At the early stage,fine-grained acicular-prismatic arsenopyrite with invisible gold was deposited;at the late stage,tabular arsenopyrite in association with free visible gold was formed.The samples of gold-bearing arsenopyrite were analyzed using Scanning Electron Microscopy,Electron Microprobe Analyses,Atomic Absorption and Laser Ablation Inductively Coupled Plasma Mass Spectrometry in combination with High Resolution 3D X-ray Computed Tomography(HRXCT).HRXCT does not destroy the studied mineral during the investigation.That technique permits to do an estimation of the amount of gold inclusions in minerals or host rocks and draw reasonable conclusions about the gold content of the ores,to study in detail the distribution patterns of metal inclusions(associated with certain minerals,cracks,crystal growth faces,etc.)and to determine the form of the gold.It can be used to understanding of the genesis of productive mineral associations,and to developing optimal technological schemes for gold extraction.展开更多
Arsenopyrite is one of the most important primary arsenic mineral. It is easily oxi-dized under hypergene conditions to release Fe, As, S and other elements. Of the released elements, dissolved arsenic is an extremely...Arsenopyrite is one of the most important primary arsenic mineral. It is easily oxi-dized under hypergene conditions to release Fe, As, S and other elements. Of the released elements, dissolved arsenic is an extremely toxic element. It is of particular importance to study arsenopyrite and the conversion of As species for environmental protection. This paper deals with the stability of arsenopyrite and As(III) in acidic Fe2(SO4)3 and FeCl3 solutions with the concentrations within the range of 10-2—10-5 mol·kg-1. Experimental researches revealed the following points: (1) under the conditions of the experiment arsenopyrite is unstable and its oxi-dation extent tends to increase with increasing Fe3+ concentration and reaction temperature and decreasing pH; (2) arsenic released during the oxidation of arsenopyrite is dominated by hydrous oxides of As(III); (3) in the FeCl3 solution the oxidation rate of arsenopyrite and As(III) toward As(V) is faster than in the Fe2(SO4)3; and (4) the stability of As(III) tends to increase with de-creasing oxidant concentration and reaction temperature, but to decrease with increasing Cl- concentration and illuminance.展开更多
Pyrolusite was added in the bioleaching process to enhance the bio-oxidation process. Bioleaching tests at different dosages of pyrolusite ore, pH and inoculation amounts of Acidithiobacillus ferrooxidans were studied...Pyrolusite was added in the bioleaching process to enhance the bio-oxidation process. Bioleaching tests at different dosages of pyrolusite ore, pH and inoculation amounts of Acidithiobacillus ferrooxidans were studied. The results showed that the time of the bio-oxidation process was decreased obviously and the arsenic leaching rate reached 94.4% after the bioleaching. The bio-oxidation of arsenopyrite and the effective extraction of manganese from pyrolusite were achieved by the bioleaching process. After bioleaching, the leaching rate of gold from the reaction residues reached 95.8% by cyanide leaching. In the bio-oxidation process, pyrolusite increased the redox potential of the solution to accelerate the bioleaching rate. The experiment showed that there were two reaction modes in the bioleaching process.展开更多
The orogenic gold deposits in Southeast Guizhou are an important component of the Xuefeng polymetallic ore belt and have significant exploration potential, but geochronology research on these gold deposits is scarce. ...The orogenic gold deposits in Southeast Guizhou are an important component of the Xuefeng polymetallic ore belt and have significant exploration potential, but geochronology research on these gold deposits is scarce. Therefore, the ore genetic models are poorly constrained and remain unclear. In the present study, two important deposits(Pingqiu and Jinjing) are investigated, including combined Re-Os dating and the He-Ar isotope study of auriferous arsenopyrites. It is found that the arsenopyrites from the Pingqiu gold deposit yielded an isochron age of 400 ± 24 Ma,with an initial ^(187)Os/^(188)Os ratio of 1.24 ± 0.57(MSWD = 0.96). An identical isochron age of 400 ± 11 Ma with an initial ^(187)Os/^(188)Os ratio of 1.55 ± 0.14(MSWD = 0.34) was obtained from the Jinjing deposit. These ages correspond to the regional Caledonian orogeny and are interpreted to represent the age of the main stage ore. Both initial ^(187)Os ratios suggest that the Os was derived from crustal rocks. Combined with previous rare earth element(REE), trace elements, Nd-Sr-S-Pb isotope studies on scheelite, inclusion fluids with other residues of gangue quartz, and sulfides from other gold deposits in the region, it is suggested that the ore metals from Pingqiu and Jinjing were sourced from the Xiajiang Group. The He and Ar isotopes of arsenopyrites are characterized by ~3 He/~4 He ratios ranging from 5.3 × 10^(-4) Ra to 2.5 × 10^(-2) Ra(Ra = 1.4 × 10^(-6), the ~3 He/~4 He ratio of air), 40 Ar=/~4 He ratios from 0.64 × 10^(-2) to 15.39×10^(-2), and ^(40)Ar/^(36)Ar ratios from 633.2 to 6582.0. Those noble gas isotopic compositions of fluid inclusions also support a crustal source origin,evidenced by the Os isotope. Meanwhile, recent noble gas studies suggest that the amount of in situ radiogenic ~4 He generated should not be ignored, even when Th and U are present at levels of only a few ppm in host minerals.展开更多
基金Yunnan Major Scientific and Technological Project(grant no.202202AG050006)National Natural Science Foundation project(grant No.42272078)Yunnan Fundamental Research Project(grant No.202401CF070094).
文摘The Saxi tungsten deposit,located in the Laojunshan ore district of southeastern Yunnan Province,is a significant W-polymetallic deposit.The origins of tungstenbearing pegmatite dikes and quartz vein mineralization in the Saxi deposit remain poorly understood.This study employs in situ U-Pb dating of apatite from the altered granite,along with trace element and S-Pb isotopic analysis of arsenopyrite,to investigate the timing,source of ore-forming fluids and the mechanisms of tungsten enrichment.The apatite in the altered granite yields a U-Pb age of 147.0±4.0 Ma,indicating magmatic activity during the Early Cretaceous.Three generations of arsenopyrite(Apy)are identified:Apy-1 in the altered granite,Apy-2 in the pegmatite dikes and Apy-3 in the quartz veins.The S/Fe ratios for Apy-1,Apy-2 and Apy-3 range from 0.98 to 1.09,0.89 to 0.92 and 0.86 to 1.02,respectively(average 0.97),suggesting a magmatic-hydrothermal origin.Sulfur isotope values(δ^(34)S=4.29‰-8.11‰)indicate that it was likely sourced from deep magmatic-hydrothermal fluids.Lead isotopic compositions of arsenopyrite suggest that the granitic parental magma is derived from the upper crust.These findings point to a magmatic-hydrothermal origin for the vein-type tungsten mineralization,linked to a concealed magmatichydrothermal system in the Early Cretaceous.
基金Project(52274348)supported by the National Natural Science Foundation of ChinaProject(2022JH1/10400024)supported by the Major Projects for the“Revealed Top”Science and Technology of Liaoning Province,China。
文摘Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.
基金Project(51074182)supported by the National Natural Science Foundation of ChinaProject(2014M550422)supported by the Postdoctoral Science Foundation,ChinaProject(2015JJ3149)supported by the Natural Science Foundation of Hunan Province,China
文摘Arsenopyrite was artificially added into the thiosulfate leaching solution to clarify the role of arsenopyrite on the thiosulfate leaching of gold.The effect of arsenopyrite on the thiosulfate leaching of gold was studied by the thermodynamic calculation,mineral dissolution test,leaching test and XPS analysis.The results show that the thiosulfate consumption slightly increases with increasing the concentration of arsenopyrite,but the gold dissolution is obviously hindered.This may mainly attribute to the catalytic effect of arsenopyrite on the thiosulfate decomposition and the formation of passivation layer on the gold foil surface.The passivation layer likely consists of Cu2S or Cu（S2O3）35-,element S,FeOOH and iron arsenate,which is deduced from the XPS analysis.However,the negative effect of arsenopyrite can be eliminated by adding additives.It is found that both additives of sodium carboxymethyl（CMC） and sodium phosphate（SHPP） can not only decrease the thiosulfate consumption but also improve the gold dissolution.
基金the National Natural Science Foundation of China(Nos.51974364,51904339,52074355)the 13th Five-Year National Key R&D Program of China(No.2020YFC1909203)。
文摘Lime(CaO)and sodium humate(NaHA)were used as the combined depressant for arsenopyrite pre-treated by CuSO_(4) and butyl xanthate.Micro-flotation tests show that the combined depressant CaO and NaHA achieved the selective depression of arsenopyrite.Closed-circuit lab-scale test results indicate that the synergistic effect of CaO+NaHA achieved a satisfactory flotation separation of sphalerite and arsenopyrite,for which the Zn grade and recovery of Zn concentrate were 51.21%and 92.21%,respectively.Contact angle measurements,adsorption amount measurements and X-ray photoelectron spectroscopy analysis indicate that the dissolved calcium species(mainly as Ca(2+))were adsorbed on the mineral surfaces,thereby promoting NaHA adsorption.Moreover,the surface of the arsenopyrite absorbed more amount of calcium species and NaHA than that of the sphalerite,thereby accounting for the strong hydrophilic surface of arsenopyrite.The adsorption of NaHA on arsenopyrite was mainly chemical adsorption through its carboxyl groups and Ca atoms,whereas that on sphalerite surface was relatively weak.
基金Project(50234010) supported by the National Natural Science Foundation of China
文摘A small molecular organic depressor glycerine-xanthate was synthesized. The effect of glycerine-xanthate on the flotation of sulfide minerals was investigated based on a function of pH value and concentration of glycerine-xanthate through flotation experiments in the presence and absence of Cu^2＋. The results show that glycerinee-xanthate has a strong dressing effect on marmatite at pH〉6 and on arsenopyrite in weak acid and base conditions with butyl-xanthate as collector. In the presence of glycerine -xanthate, marmatite is activated by addition of Cu^2＋, but arsenopyrite cannot be activated and remains unfloatable. So the selective separation can be achieved for two minerals. The depression of glycerine-xanthate on sulfide minerals was discussed based on the radical electronegative calculation and the theory of HSAB. Infrared spectrum shows that there are some -OH and-CSS-in glycedne-xanthate molecule, which competes with butyl-xanthate on the mineral surface. As a result of many hydrophilic groups in glycerine-xanthate, the surfaces of marmatite and arsenopyrite become hydrophilic, thus the flotation of marmatite and arsenopyrite is depressed. The collector is adsorbed preferentially on the surface of marmatite and it shows a better floatability in the presence of Cu^2＋, whereas, the surface of arsenopyrite absorbs glycerine-xanthate and the flotation of arsenopyrite is depressed by glycerine-xanthate.
基金the National Natural Science Foundation of China(Nos.52074139,51904129)Basic Research Project of Yunnan Province,China(No.202001AU070028)+2 种基金Basic Research Project for High-level Talents of Yunnan Province,China(No.KKS2202152011)Open Foundation of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,China(No.CNMRCUKF1602)the Testing and Analyzing Funds of Kunming University of Science and Technology,China(No.2020T20150055).
文摘Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collector was investigated by flotation experiments,contact angle measurements,adsorption measurements,localized electrochemical impedance spectroscopy(LEIS)measurements,and X-ray photoelectron spectroscopy(XPS)analyses.The results showed that K_(2)FeO_(4)strongly depressed arsenopyrite in a pH range of 4−11,and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^(−4)mol/L K_(2)FeO_(4)and 5×10^(−5)mol/L PEX at pH 8 or 10.In the presence of K_(2)FeO_(4) and PEX,the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly.LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface.XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.
文摘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 %.
基金supported by Yunnan Major Scientific and Technological Projects,China(No.202202AG050015)National Natural Science Foundation of China(No.51504109)。
文摘The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated pyrite in high alkalinity and high Ca^(2+)system,whereas arsenopyrite was almost unaffected.In mineral mixtures tests,the recovery difference between pyrite and arsenopyrite after adding ammonium oxalate is more than 85%.After ammonium oxalate and ethyl xanthate treatment,the hydrophobicity of pyrite increased significantly,and the contact angle increased from 66.62°to 75.15°and then to 81.21°.After ammonium oxalate treatment,the amount of ethyl xanthate adsorption on the pyrite surface significantly increased and was much greater than that on the arsenopyrite surface.Zeta potential measurements showed that after activation by ammonium oxalate,there was a shift in the zeta potential of pyrite to more negative values by adding xanthate.X-ray photoelectron spectroscopy test showed that after ammonium oxalate treatment,the O 1s content on the surface of pyrite decreased from 44.03%to 26.18%,and the S 2p content increased from 14.01%to 27.26%,which confirmed that the ammonium oxalatetreated pyrite surface was more hydrophobic than the untreated surface.Therefore,ammonium oxalate may be used as a selective activator of pyrite in the lime system,which achieves an efficient flotation separation of S-As sulfide ores under high alkalinity and high Ca2+concentration conditions.
基金the Natural Science Basic Research Program of Shaanxi,China(No.2020JQ-666)the National Natural Science Foundation of China(Nos.52004198,51934009).
文摘The galvanic interaction of arsenopyrite−magnetite in acidic culture medium was investigated by electrochemical measurements,X-ray photoelectron spectroscopy characterization and leaching experiments.The results indicated that the rest potential of magnetite was 321 mV,which was more anodic than 223 mV of arsenopyrite,and the galvanic current was 7.40μA,verifying the existence of the galvanic interaction between arsenopyrite and magnetite.The galvanic potential and polarization curves suggested that the redox behaviors of arsenopyrite dominated the overall galvanic interaction.The galvanic interaction enhanced the electrochemical dissolution of arsenopyrite with the generation of more oxidation products(S^(0),SO_(3)^(2−),SO_(4)^(2−)and AsO_(3)^(3−)) on arsenopyrite and an increase in the chemical reactivity of the surface.Leaching experiments of 6 days showed that the presence of magnetite improved the arsenic release from arsenopyrite by 30 mg/L,and further confirmed the enhanced oxidation of arsenopyrite when coupled with magnetite.
基金This work was financially supported by National Natural Science Foundation of China(Nos.51774342,41802038,U1608254,51861135305,and 41830318)Beijing Syn-chrotron Radiation Facility Public User Program(2018-BEPC-PT-002240).
文摘Understanding bacterial adsorption and the evolution of biofilms on arsenopyrite with different surface structures is of great signific-ance to clarifying the mechanism of microbe-mineral interfacial interactions and the production of acidic mine drainage impacting the environ-ment.In this study,the attachment of Sulfobacillus thermosulfidooxidans cells and subsequent biofilm formation on arsenopyrite with different surface structures in the presence of dissolved As(Ⅲ)was studied.Arsenopyrite slices with a specific surface were obtained by electrochemic-al corrosion at 0.26 V.The scanning electronic microscopy-energy dispersion spectra analyses indicated that the arsenopyrite surface deficient in sulfur and iron obtained by electrochemical treatment was not favorable for the initial adsorption of bacteria,and the addition of As(Ⅲ)in-hibited the adsorption of microbial cells.Epifluorescence microscopy showed that the number of cells attaching to the arsenopyrite surface in-creased with time;however,biofilm formation was delayed significantly when As(Ⅲ)was added.
文摘Based on comprehensive analysis of the crystal structure, chemical and phase composition of natural arsenopyrite of the "Panimba" deposit (Krasnoyarsk region), an analytical expression for calculating the impurity density in structure of minerals type of marcasite are received.
文摘The thermal decomposition of pyrite, arsenopyrite and auriferous concentrates in the presence of sodium hydroxide was studied by using TG DTA and XRD methods. For the arsenopyrite mineral the reaction takes place at 200～350℃ with the formation of Na 2SO 4, Na 3AsO 4, FeSO 4, Fe 8As 10 O 23 and FeAs, and a large amount of FeAsS do not decompose at this temperature. When the temperature arrives at 800℃, the exothermic reaction takes place with the formation of Na 3AsO 4, Na 2SO 4, Fe 2O 3 and a little amount of As 4S 3. For the pyrite mineral the reaction takes place between 200～350℃ with the formation of Fe 2(SO 4) 3, Fe 3S 4, FeS, Na 2Fe(SO 4) 2 in addition to unreacted FeS 2 and NaOH. When the temperature arrives at 800℃, almost all the pyrite decomposes and the Fe 2O 3, Na 2SO 4, Fe(SO 4) 3 and a minor amount of Fe 1- x S are produced. The decomposition temperatures of arsenopyrite and pyrite get lower as their particle sizes are small. The results also indicated that with the addition of an appropriate amount of NaOH, nearly complete containment of arsenic and sulphur during the decomposition of auriferous concentrate may be possible.
基金Financially supported by the National Natural Science Foundation of China
文摘The kinetics of the catalytical oxidation acid leaching of arsenopyrite is studied in the HNO<sub>3</sub>-H<sub>2</sub>SO<sub>4</sub>-O<sub>2</sub> aqueous system. In addition to the effect of reaction time on the extraction of arsenopyrite and distribution of products, the effects of operation factors and several additives on the reaction rate are also investigated. The experi mental results show that the oxidation rate is greatly dependent on nitric acid concentration, average radius of samples and acid concentration. The elemental sulphur produced does not interfere with the progress of the reacation process. It is found that a shrinking core model with chemical reaction controlling, which is expressed as 1-（1-α）<sup>1/3</sup>=kt, may be adopted to describe the kinetics results. The apparent activation energy is tested to be 23. 6 kJ/mol.
文摘In this paper, the separation of arsenopyrite from chalcopyrite, pyrite, galena with organic depressants （guergum and sodium humic ） was discussed, and the functioning mechanism of those organic depressants was discussed. The experimental results of monomineral flotation indicated that both guergum and sodium humic have depressing effect on arsenopyrite in the presence of ethyl xanthate. Guergum and sodium humic showed different depressing ability to pyrite, chalcopyrite and galena, and the higher the pH value in pulp, the stronger the depressing ability. Ultraviolet-Visible Spectrophotometric study showed that the adsorption layer of xanthate on surface of minerals had been desorhed by the two organic depressants, and the selective desorption of the collector layer was found from different minerals. The xanthate cover on minerals surface was set free when dosage of the organic depressants was high enough. For artificially-mixed minerals, the separation of arsenopyrite from other sulphides was successfully realized by controlling dosage of the organic depressants. And sodium humic had been concentrates in a commercial Lead-Zinc concentrator.
文摘Arsenopyrite is one of very important and common auriferous minerals in endogenetic gold deposits. In seven gold deposits, the prospecting typomorphic characteristics of arsenopyrite, such as morphological typomorphism, composition typomorphism, pyroelectricity typomorphism and so on, were established. The crystal form of arsenopyrite is simple, and the form symbols mainly are {101}, {120}, {210}, {140}, {230}, {012}, etc. The smaller grain and poor crystal form arsenopyrite indicates the better auriferous characteristics. The major elements (Fe, As and S) of gold-bearing arsenopyrite usually show Fe/As+S>0.5,As/S<1 which deviates from its theoretical value. The most important trace element is Au and next is Ag in arsenopyrite, and they often show the positive correlation. The pyroelectricity of arsenopyrite can reflect the mineralization epoch, and it also is related to the crystal form and granudarity.
基金supported by the National Natural Science Foundation of China(Nos.52274255 and 52404276)Fundamental Research Funds for the Central Universities(Nos.N2301003,N2201008,N2201004,and N2301025)+2 种基金Postdoctoral Foundation of Northeastern UniversityYoung Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)China Postdoctoral Science Foundation(No.2022M720025)
文摘Avoiding the formation of a passivation layer comprising intermediate products and secondary minerals is a principal challenge in preoxidizing arsenical gold ores.Due to the similar crystal,pyrite(Py) always coexists with arsenopyrite(Ap) and effects the oxidation,although its mechanism needs to be improved.Therefore,this study focuses on a mixed leaching system involving Py and Ap.The effects of refactoring the passivation layer structure through Ap oxidation using Py under various pH conditions is systematically investigated.The role of Py in the formation and regulation of the Ap passivation layer is clarified using advanced characterization techniques.The study results indicate that Py decreased the pH,causing the ferric arsenate in the passivation layer of Ap oxidation to become soluble.Furthermore,the addition of Py decreased the jarosite content in the passivation layer.These reconstruction effects of Py on the passivation layer of the Ap surface considerably enhanced Ap oxidation.The highest level of arsenic dissolution(821.43 mg/L) was observed at the mass ratio of Py and Ap at 2(Py/Ap=2),representing an obvious increase compared to the control group(520.96 mg/L).This study focuses on the reconstruction of the passivation layer by Py,and further elucidates the role of Py in enhancing Ap oxidation during the pretreatment of arsenical gold ores,thereby advancing our understanding of the interaction rules between gold-bearing minerals of arsenical gold ores.
基金financial support for the project by the Russian Federation represented by the Ministry of Education and Science of Russia(project number 13.1902.24.44,agreement number 075-15-2024-641).
文摘The distribution of gold in small acicular arsenopyrite of a pyrite-arsenopyrite association from Suzdal(Eastern Kazakhstan),Olympiada(Yenisei Ridge,Russia)and large pseudorhombic arsenopyrite crystals from Bazovskoe(Yakutia,Russia)orogenic-type deposits were investigated.On orogenic gold deposits in NE Asia,occurring mainly in black shales,two productive stages of ore deposition are distinguished,which correspond to two morphological varieties of arsenopyrite.At the early stage,fine-grained acicular-prismatic arsenopyrite with invisible gold was deposited;at the late stage,tabular arsenopyrite in association with free visible gold was formed.The samples of gold-bearing arsenopyrite were analyzed using Scanning Electron Microscopy,Electron Microprobe Analyses,Atomic Absorption and Laser Ablation Inductively Coupled Plasma Mass Spectrometry in combination with High Resolution 3D X-ray Computed Tomography(HRXCT).HRXCT does not destroy the studied mineral during the investigation.That technique permits to do an estimation of the amount of gold inclusions in minerals or host rocks and draw reasonable conclusions about the gold content of the ores,to study in detail the distribution patterns of metal inclusions(associated with certain minerals,cracks,crystal growth faces,etc.)and to determine the form of the gold.It can be used to understanding of the genesis of productive mineral associations,and to developing optimal technological schemes for gold extraction.
基金This work was part of the research project"On the influence of geological environment on the development of economy and sustained development"under the Sino-Canadian Cooperative Program(SULCP).Prof.Gammons offered great help with the establishment of this project.This project was financially supported jointly by the National Natural Science Foundation of China(Grant No.49773202)the Key Laboratory of Ore Deposit Geochemistry,the Institute of Geochemistry,the Chinese Academy of Sciences.
文摘Arsenopyrite is one of the most important primary arsenic mineral. It is easily oxi-dized under hypergene conditions to release Fe, As, S and other elements. Of the released elements, dissolved arsenic is an extremely toxic element. It is of particular importance to study arsenopyrite and the conversion of As species for environmental protection. This paper deals with the stability of arsenopyrite and As(III) in acidic Fe2(SO4)3 and FeCl3 solutions with the concentrations within the range of 10-2—10-5 mol·kg-1. Experimental researches revealed the following points: (1) under the conditions of the experiment arsenopyrite is unstable and its oxi-dation extent tends to increase with increasing Fe3+ concentration and reaction temperature and decreasing pH; (2) arsenic released during the oxidation of arsenopyrite is dominated by hydrous oxides of As(III); (3) in the FeCl3 solution the oxidation rate of arsenopyrite and As(III) toward As(V) is faster than in the Fe2(SO4)3; and (4) the stability of As(III) tends to increase with de-creasing oxidant concentration and reaction temperature, but to decrease with increasing Cl- concentration and illuminance.
基金Project(2015ZX07205-003)supported by the National Water Pollution Control and Treatment Science,ChinaProject(DY125-15-T-08)supported by China Ocean Mineral Resource R&D Association+1 种基金Project(2012BAB07B05)supported by the National Key Technology R&D Program of ChinaProject(2012AA062401)supported by the National High-tech Research and Development Program of China
文摘Pyrolusite was added in the bioleaching process to enhance the bio-oxidation process. Bioleaching tests at different dosages of pyrolusite ore, pH and inoculation amounts of Acidithiobacillus ferrooxidans were studied. The results showed that the time of the bio-oxidation process was decreased obviously and the arsenic leaching rate reached 94.4% after the bioleaching. The bio-oxidation of arsenopyrite and the effective extraction of manganese from pyrolusite were achieved by the bioleaching process. After bioleaching, the leaching rate of gold from the reaction residues reached 95.8% by cyanide leaching. In the bio-oxidation process, pyrolusite increased the redox potential of the solution to accelerate the bioleaching rate. The experiment showed that there were two reaction modes in the bioleaching process.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos. 41303038, 41772070)Open Fund of State Key Laboratory of Ore Deposit Geochemistry (201502)the National Basic Research Program of China (2014CB440904)
文摘The orogenic gold deposits in Southeast Guizhou are an important component of the Xuefeng polymetallic ore belt and have significant exploration potential, but geochronology research on these gold deposits is scarce. Therefore, the ore genetic models are poorly constrained and remain unclear. In the present study, two important deposits(Pingqiu and Jinjing) are investigated, including combined Re-Os dating and the He-Ar isotope study of auriferous arsenopyrites. It is found that the arsenopyrites from the Pingqiu gold deposit yielded an isochron age of 400 ± 24 Ma,with an initial ^(187)Os/^(188)Os ratio of 1.24 ± 0.57(MSWD = 0.96). An identical isochron age of 400 ± 11 Ma with an initial ^(187)Os/^(188)Os ratio of 1.55 ± 0.14(MSWD = 0.34) was obtained from the Jinjing deposit. These ages correspond to the regional Caledonian orogeny and are interpreted to represent the age of the main stage ore. Both initial ^(187)Os ratios suggest that the Os was derived from crustal rocks. Combined with previous rare earth element(REE), trace elements, Nd-Sr-S-Pb isotope studies on scheelite, inclusion fluids with other residues of gangue quartz, and sulfides from other gold deposits in the region, it is suggested that the ore metals from Pingqiu and Jinjing were sourced from the Xiajiang Group. The He and Ar isotopes of arsenopyrites are characterized by ~3 He/~4 He ratios ranging from 5.3 × 10^(-4) Ra to 2.5 × 10^(-2) Ra(Ra = 1.4 × 10^(-6), the ~3 He/~4 He ratio of air), 40 Ar=/~4 He ratios from 0.64 × 10^(-2) to 15.39×10^(-2), and ^(40)Ar/^(36)Ar ratios from 633.2 to 6582.0. Those noble gas isotopic compositions of fluid inclusions also support a crustal source origin,evidenced by the Os isotope. Meanwhile, recent noble gas studies suggest that the amount of in situ radiogenic ~4 He generated should not be ignored, even when Th and U are present at levels of only a few ppm in host minerals.
