MOLECULES
·
2024
·Vol. 29
·期 7
·1490
·
IF 4.2
Qiang Song,Xiong Tong,Pulin Dai,Xian Xie,Ruiqi Xie,Peiqiang Fan,Yuanlin Ma,Hang Chen
In industrial manufacturing, pyrrhotite(Fe1−xS), once depressed, is commonly activated for flotation. However, the replacement of CuSO4is necessary due to the need for exact control over the dosage during the activation of pyrrhotite, which can pose challenges in industrial settings. This research introduces the use of FeSO4for the first time to efficiently activate pyrrhotite. The impact of two different activators on pyrrhotite was examined through microflotation experiments and density functional theory (DFT) calculations. Microflotation experiments confirmed that as the CuSO4dosage increased from 0 to 8 × 10−4mol/L, the recovery of pyrrhotite initially increased slightly from 71.27% to 87.65% but then sharply decreased to 16.47%. Conversely, when the FeSO4dosage was increased from 0 to 8 × 10−4mol/L, pyrrhotite’s recovery rose from 71.27% to 82.37%. These results indicate a higher sensitivity of CuSO4to dosage variations, suggesting that minor alterations in dosage can significantly impact its efficacy under certain experimental conditions. In contrast, FeSO4might demonstrate reduced sensitivity to changes in dosage, leading to more consistent performance. Fe ions can chemically adsorb onto the surface of pyrrhotite (001), creating a stable chemical bond, thereby markedly activating pyrrhotite. The addition of butyl xanthate (BX), coupled with the action of Fe2+on activated pyrrhotite, results in the formation of four Fe-S bonds on Fe2+. The proximity of their atomic distances contributes to the development of a stable double-chelate structure. The S 3p orbital on BX hybridizes with the Fe 3d orbital on pyrrhotite, but the hybrid effect of Fe2+activation is stronger than that of nonactivation. In addition, the Fe-S bond formed by the addition of activated Fe2+has a higher Mulliken population, more charge overlap, and stronger covalent bonds. Therefore, Fe2+is an excellent, efficient, and stable pyrrhotite activator.
研究领域:
矿物加工工程
·
理论化学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Sultan Ahmed Khoso,Fei Lyu,Xiangsong Meng,Yuehua Hu,Wei Sun
Pyrite depression in xanthate flotation of multiple sulphide minerals has become a serious problem in every mineral industry. The present study introduces a novel and non-hazardous depressant reagent scheme in selective flotation of chalcopyrite from pyrite with sodium butyl xanthate (SBX) as the collector. The combined inhibitory effect of an organic polymer, tricarboxylate sodium starch (TCSS), and calcium oxide (CaO) depressed the flotation of pyrite more strongly than that of the chalcopyrite in a wide pH range of 7–12. The synergistic effect of CaO and TCSS achieved an improved selective flotation separation of chalcopyrite from pyrite at low alkaline pH of 9, for which the recovery of chalcopyrite was over 80% and that of pyrite was less than 19%. The IR spectral, XPS spectral, UV–vis spectral and zeta potential measurements indicated that the surface of pyrite adsorbed significantly more amount of CaO and TCSS than that of the chalcopyrite. The dissolved calcium species preferentially adsorbed on the pyrite surface decreasing its negative charge and promoting TCSS adsorption. The findings of this research are of great significance in reducing the consumption of larger doses of lime in conventional Cu–Fe flotation circuits of the copper industry.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2016
·
IF 5.991
Peng Zhang,Weiyu Yao,Songhu Yuan
The release of arsenic (As) from the oxidation of As-rich pyrite is an important source of the high arsenic in groundwater. As a widespread low-molecular-weight organic acid , citrate plays an important role on the cycling of Fe(II)/Fe(III) through complexation in circumneutral subsurface environments, while the influence of citrate on the release of As from the oxidation of As-rich pyrite is poorly understood. In this study, As was loaded onto pyrite particles under anoxic conditions , and its release was investigated in the presence of 0–1 mM citrate at pH 7.4 under oxic conditions . As-loaded pyrite suspension was prepared by the equilibrium of 2.67 μM As(III) in 10 g/L pyrite under anoxic conditions with the decrease in dissolved As(III) concentration to 1 μM. The suspension was subsequently exposed to air for oxygenation. In the absence of citrate, the oxygenation decreased the partitioning of As in the solution because of the re-adsorption of aqueous As by the in situ generated Fe(III) oxyhydroxides. However, with the increase in citrate concentration from 0.1 to 1 mM, the As partitioned in the solution increased from 0.3 to 2.67 μM. In the presence of 1 mM citrate, the As(III) was almost completely oxidized to As(V) during the oxygenation. The mechanisms of citrate-enhanced release of As were mainly attributed to the ligand exchange of citrate with As for pyrite surface sites, the competitive adsorption of citrate with As on Fe(III) oxyhydroxides and pyrite, and the partitioning of As on the newly formed Fe(III) colloids. This finding presents an overlooked mechanism of the release of pyrite-associated As under oxic and circumneutral conditions.
研究领域:
环境科学
·
地球化学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Kai Jia,Qiming Feng,Guofan Zhang,Wanying Ji,Wukai Zhang,Bingqian Yang
Smithsonite is a readily dissolvable carbonate mineral that is naturally hydrophilic, making recovery of this ore by flotation difficult. The flotation results showed that conditioning with only sodium sulfide (Na 2 S) did not successfully allow the smithsonite samples to float, whereas treatment with a combination of S(II), Pb(II) and xanthate (with Na 2 S as the sulfurizing reagent, lead ions (Pb(II)) as the activator, and xanthate as the collector) improved the flotation of smithsonite, achieving a mass recovery of 95.8%. A combination of analytical techniques, including X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), in conjunction with depth profiling , was used to investigate the chemical nature of the sulfur and lead species on the smithsonite surface. For S(II)-conditioned smithsonite, a layer of ZnS formed on the smithsonite (ZnCO 3 ) substrates; this newly formed ZnS coating was amorphous or poorly crystallized. For smithsonite samples conditioned with S(II) and Pb(II), the microstructures and the phase constituents, obtained by AFM and XRD analyses, confirmed the formation of the PbS species with a cubic galena structure on the surface. XPS depth profiling showed that the PbS layer was 18-nm thick, which corresponds to 30 PbS molecular layers . This study presents direct evidence that the coating of the activation product, PbS, on the smithsonite surface was similar to a relatively thick galena layer, which led to successful flotation.
研究领域:
矿物学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2019
·
IF 3.413
Bin Luo,Quanjun Liu,Jiushuai Deng,Li Yu,Hao Lai,Chao Song,Shimei Li
Beneficiation of zinc from low-grade oxidized zinc ores has become the focus of recent studies. Sulfidation is an important process to recover zinc from oxidized zinc ores in flotation . Although some studies have reported on the sulfidation-flotation of smithsonite, the effect of sulfide ions on sulfide film thickness remains unknown when the oxidized zinc ores start floating and achieve excellent flotation. In this work, the influence of sulfur ions on smithsonite flotation in a dodecylamine system were investigated by micro-flotation experiments, inductively coupled plasma-atomic emission spectrometry (ICP-AES), zeta potential measurements, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Micro-flotation experiment results show that smithsonite starts floating after treatment with a low S concentration of 5 × 10 −5 mol/L, while excellent flotation was obtained following treatment with a high S concentration of 5 × 10 −4 mol/L. Compared to the low S solution, excellent hydrophobicity of smithsonite was obtained owing to the adsorption of more sulfide ions, making the mineral surface potential more negative, and forming a thicker heterogeneous zinc-sulfide film that primary consists of zinc monosulfide and zinc polysulfide . The zinc-sulfide film thickness on the smithsonite surface was approximately 7.79 nm when the smithsonite started floating, while excellent floatation was obtained as the zinc-sulfide film thickness reached about 12.13 nm.
研究领域:
矿物加工工程
·
冶金工程
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DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2018
·Vol. 25
·期 5
·481-488
·
IF 1.261
Li Zhi-li,Rao Feng,Song Shao-xian,Li Yan-mei,Liu Wen-biao
In saline water flotation, the salinity can cause a distinguishable slime coating of clay minerals on chalcopyrite particles through its effect on their electrical double layers in aqueous solutions. In this work, kaolinite was used as a representative clay mineral for studying slime coating during chalcopyrite flotation. The flotation of chalcopyrite in the presence and absence of kaolinite in tap water, seawater, and gypsum-saturated water and the stability of chalcopyrite and kaolinite particles in slurries are presented. Zeta-potential distributions and scanning electron microscopy images were used to characterize and explain the different slime coating degrees and the different flotation performances. Kaolinite particles induced slime coating on chalcopyrite surfaces and reduced chalcopyrite floatability to the greatest extent when the pH value was in the alkaline range. At 0.24wt% of kaolinite, the chalcopyrite floatability was depressed by more than 10% at alkaline pH levels in tap water. Salinity in seawater and gypsum-saturated water compressed the electrical double layers and resulted in extensive slime coating.
研究领域:
矿物加工工程
·
表面化学
·
采矿工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Fei Li,Sihai Zhang,Nengwu Zhu,Junyao Ke,Yun Zhao,Weiwen Ma,Pingxiao Wu
A deep understanding of the binding relationship between Fe 2 SiO 4 and heavy metals from the perspective of lattice site substitution is essential to improve the theoretical knowledge regarding heavy metals binding in copper smelting slags (CSS). Here, we proposed the lattice site substitution behavior of heavy metals in Fe 2 SiO 4 by preparing M-Fe 2 SiO 4 (M = Cu, Pb, and As). X-ray diffraction refinement, scanning electron microscopy, and Fourier transform-infrared spectroscopy analysis showed that heavy metals were involved in the formation of Fe 2 SiO 4 during the smelting process. Compared with pure Fe 2 SiO 4 , the fine structure of M-Fe 2 SiO 4 was significantly changed by the lattice substitution of heavy metals. X-ray photoelectron spectroscopy and Raman and Mossbauer spectra combined with Density Functional Theory calculation confirmed that the divalent metal elements including Cu and Pb were bound to the Fe 2 SiO 4 lattice by replacing M2 site. However, the trivalent As element could substitute both the positions of M2 site and part of the central Si atom through a charge compensation mechanism. Overall, the proposed lattice site substitution behavior of heavy metals in Fe 2 SiO 4 could enrich the theory of the lattice substitution of heavy metals in CSS, also further provide guidance for the comprehensive disposal of CSS.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL GEOLOGY
·
2025
·
IF 3.6
Xianghao Zha,Guangxia Liu,Ning Chen,Yu Zeng,Juan Wang,Ziyan Yang,Huan Tang,Guodong Fang
The iron and sulfur species play key roles in the transformation and immobilization of heavy metals (e.g., As(III)) in soil environments, while the underlying mechanism of these processes was not fully explored. In this study, the effects of sulfite (an important intermediate of sulfur species) on As(III) transformation induced by troilite (FeS) were investigated. Results showed that the presence of sulfite not only greatly enhanced As(III) oxidation by FeS, with k obs increased by approximated 30 times, but also significantly increased the As(III) immobilization on FeS surface. Further analysis reveal that sulfate radicals (SO 4 •− ) and hydroxyl radicals ( • OH), derived from the redox reactions of surface Fe(II)/Fe 2+ with sulfite, were the main contributors to As(III) oxidation. In addition, As(III) oxidation was significantly enhanced in the sulfite/FeS system over a wide pH range, and oxygen was a prerequisite for the generation of free radicals. Besides, the dissolved As can be efficiently immobilized on FeS surface through co-precipitation with amorphous Fe(OH) 3 phases, which was negligibly affected by the presence of anions and organic matters. This study provides new insights into the mechanism by which sulfur species drive the transformation and immobilization of As(III) during oxygenation of iron-sulfide minerals.
研究领域:
环境科学
·
土壤化学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Jiajun Liu,Guofan Zhang,Binbin Li,Xinya Fu,Sen Li
In this study, we aimed to address the problem of fine-grained serpentine forming “slime coating” on the surface of pyrite, which deteriorates the flotation of pyrite, by systematically investigating the effects of HPMA on the separation of pyrite and serpentine, as well as the underlying mechanism. The flotation results indicated that the recovery of pyrite deteriorated by serpentine was significantly increased and reached 90 % by adding 30 mg/L of HPMA at pH 9.00. The total organic carbon (TOC) test and zeta potential test results revealed that the adsorption of HPMA on serpentine was much stronger than that on pyrite. The adsorption behavior was confirmed by X-ray photoelectron spectroscopy (XPS) analyses, which demonstrated that HPMA could chelate with positively charged Mg ions on the surface of serpentine, resulting in a significant change in the surface charge of serpentine to a negative state. The positive effect of HPMA on pyrite flotation was visualized by a scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) analyzer and characterized by the major elemental content. As a result of the addition of HPMA, the surface charge of serpentine was changed from positive to negative, which resulted in the disruption of co-cohesion between serpentine and pyrite. This result enhanced the natural floatability of pyrite and the adsorption of collector potassium amyl xanthate (PAX) on pyrite, thus achieving the selective flotation between pyrite and serpentine.
研究领域:
矿物加工工程
·
环境科学
✓ 已验证
DOI
高影响因子
Chinese Physics B
·
2022
·Vol. 31
·期 6
·066206
·
IF 1.652
Yao Wang,Dan Xu,Shan Gao,Qi Chen,Dayi Zhou,Xin Fan,Xin-Jian Li,Lijie Chang,Yuewen Zhang,Hongan Ma,Xiao-Peng Jia
Pyrite tailings are the main cause of acid mine wastewater. We propose an idea to more effectively use pyrite, and it is modified by exploiting the reducibility of metal represented by Al under high-pressure and high-temperature (HPHT) conditions. Upon increasing the Al addition, the conductivity of pyrite is effectively improved, which is nearly 734 times higher than that of unmodified pyrite at room temperature. First-principles calculations are used to determine the influence of a high pressure on the pyrite lattice. The high pressure increases the thermal stability of pyrite, reduces pyrite to high-conductivity Fe7S8 (pyrrhotite) by Al. Through hardness and density tests the influence of Al addition on the hardness and toughness of samples is explored. Finally we discuss the possibility of using other metal-reducing agents to improve the properties of pyrite.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Zhongxian Wu,Youjun Tao,Dongping Tao
Hydrodynamic cavitation nanobubble flotation has proven to be effective in enhancing flotation performance of fine pyrite particles and reducing the required collector dosage with xanthate used as collector. However, the mechanism of reduced collector dosage in the presence of nanobubble has not been well investigated. This study was performed with the focus on understanding the contribution of nanobubbles to sodium amyl xanthate (SAX) adsorption on pyrite surface. The results have shown that the adsorption of SAX on pyrite surface fits the Freundlich isotherms with or without the presence of cavitation nanobubbles, indicating SAX adsorption can result in single or multilayers. The introduction of cavitation nanobubbles increased the SAX adsorption capacity and kinetics in the form of nonpolar dixanthogen nanodroplets on pyrite surface. Both hydroxyl radicals (⋅OH) and dissolved oxygen (DO) produced by bulk nanobubbles (BNBs) during cavitation contributed to oxidation of SAX to dixanthogen in the bulk phase of slurry with minimal impacts on pyrite surface. The oxidation effect was more pronounced with increased cavitation time. Electrochemical measurements such as cyclic voltammetry (CV) and Tafel polarization analysis confirm that the presence of BNBs enhanced the SAX adsorption on pyrite surface, while the preferential formation of SNBs (surface nanobubbles) on hydrophobic pyrite surface prevented the contact of oxygen species with pyrite, thereby avoiding further oxidation of the surface. The presence of ·OH and DO reduced the induction time for bubble-particle attachment by 100–250 ms and increased the contact angle by 5° −10° in the nanobubble flotation system.
研究领域:
化学工程
·
材料科学
·
矿物加工
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Xin Lv,Hongbo Zhao,Yisheng Zhang,Zefan Yan,Yu Zhao,Hong Zheng,Wenqing Liu,Jianping Xie,Guanzhou Qiu
Although pyrite bio-dissolution plays an important role in the processing of sulfide ores, the formation of passivation film inhibited the further dissolution of sulfide ores. In order to enhance the dissolution of sulfide ores, a novel method for destroying the passivation film using ozone was proposed and verified. The generated passivation film inhibiting pyrite dissolution in the presence of Leptospirillum ferrooxidans and Acidithiobacillus thiooxidans was studied. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results indicate that a passivation film mainly consisting of jarosite and polysulfide (S n n− /S 0 ) might be formed during biotic stage, which can be eliminated with the introduction of ozone (2 g/min) in 30 min. Electrochemical results show that ozone significantly increased the electrochemical reactivity of passivated pyrite, further proving that ozone enhanced the dissolution of passivated pyrite through destroying the passivation layer. Hence, a bi-stage method for dissolution of sulfide ores can be proposed.
研究领域:
微生物学
·
矿物加工工程
✓ 已验证
DOI
PubMed
高影响因子
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