MINERALS ENGINEERING
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2024
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IF 4.9
Jie Wu,Bingqiao Yang,Rudolph Martin,Shaoxian Song,Mildred Quintana,Feifei Jia,Huihua Luo,Fang Zhou,Xiang Tian
Utilizing xanthate in bulk flotation of Cu-Mo sulfide ores is inevitable, but the implication of xanthate on the flotation of molybdenite fines is barely understood. In this study, the influence of sodium butyl xanthate (SIBX) on the flotation of molybdenite fines and the interaction mechanism was comprehensively investigated by micro-flotation tests, contact angle, adsorption capacity, electrochemical tests, atomic force microscopy (AFM), Fourier Transform Infrared Spectrometer (FTIR), X-ray Photoelectron Spectroscopy (XPS) and density functional theory (DFT) calculations. Micro-flotation tests indicated that SIBX significantly enhanced the flotation of molybdenite fines across a wide pH range. Contact angle, adsorption capacity, Tafel curves, AFM, FTIR and XPS results suggested both xanthate and dixanthogen species adsorbed on molybdenite surfaces, thus improving the hydrophobicity of both edges and faces. Rest potential measurements clarified dixanthogen species dominated on faces while xanthate ions prevailed on edges. DFT calculations elucidated dixanthogen physically adsorbed (−66.06 kJ/mol) on faces while xanthate chemisorbed (−235.62 kJ/mol) on edges via the hybridization of two S atoms within SIBX with two Mo atoms to form highly covalent bonds. This work first clearly unveiled the anisotropic adsorption mechanism of SIBX species on faces and edges, significantly improving the flotation efficiency of molybdenite fines.
研究领域:
矿物加工工程
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表面化学
✓ 已验证
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
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IF 3.975
Xianlin Xu,Jiajing Yu,Chang Liu,Guang Yang,Lei Shi,Xupin Zhuang
Biomass can adsorb dyes and then degrade. Although this material has remarkable prospects, its application is limited by its adsorption capacity and the simultaneous adsorption of cations/anions. Herein, a pore-forming agent in a solvent exchange phase transformation was used to fabricate chitosan xanthate and cellulose xanthate (xanthated chitosan/cellulose) sponges. Owing to the hierarchical pores and the presence of xanthic acid and amino groups, the sponges show efficient removal ability for anionic (congo red) and cationic (methylene blue) dyes. The adsorption mechanism, isotherm, kinetics, and thermodynamics were comprehensively studied. The xanthated chitosan/cellulose sponges exhibited the maximum adsorption capacities of 213.220 and 289.855 mg g −1 toward methylene blue and Congo red, respectively. The mechanism is a spontaneous physic-sorption process that fitted well with the pseudo-second-order and Langmuir isotherm models. These results revealed that xanthated chitosan/cellulose sponges are effective adsorbents for the removal of methylene blue and Congo red dyes and provide a new platform for dye decontamination .
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2019
·
IF 0
Pingfeng Fu,Lianghua Wang,Yanhong Ma,Zongwu Hou
To separate sulfide minerals from ores, xanthates are widely used as flotation collectors in global mining industry. However, nearly half of xanthates dosed into flotation circuits are discharged into flotation effluents. Residual xanthates and byproducts must be removed because of their toxicity to animals and detrimental effects on mineral flotation. In this work, the degradation of ethyl xanthate (EX) collector by O 3 , UV 254nm , UV 185+254nm , O 3 /UV 254nm and O 3 /UV 185+254nm was compared. The TOC and SO 4 2− concentrations were measured to study the mineralization of EX. The generation of CS 2 and H 2 S byproducts was investigated in both aqueous and gaseous phases. The degradation rate and mineralization extent of EX had the order O 3 /UV 185+254nm >O 3 /UV 254nm >UV 185+254nm >UV 254nm >sole O 3 . The EX removal by O 3 /UV 185+254nm reached 99.13 % within 15 min with the half-life of 2.29 min. The higher solution pH promoted the EX degradation for the O 3 /UV 185+254nm and sole O 3 . After 90 min, 1.72 % of total sulfur in EX had emitted into gas for the O 3 /UV 185+254nm , slightly higher than that (0.49 %) for sole O 3 . The solid phase extraction and gas chromatography‒mass spectrometry (SPE/GC–MS) and UV–vis spectroscopic analysis revealed that 13 organic byproducts were generated from EX collector and most of them could be further decomposed by O 3 /UV 185+254nm . Because the O 3 /UV 254nm and UV 185+254nm photolysis were included, the O 3 /UV 185+254nm was the most efficient process in the removal and mineralization of xanthate collectors among five processes.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2025
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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
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材料科学
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矿物加工
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Dejian Li,Xuemin Chen,Chenrui Liu,Jiang Tian,Feng Li,Yun Liu
In previous works, both tannic acid (TA) and organosilane-based passivators have been proven to possess good inhibition effects on pyrite oxidation, which could effectively prevent acid mine drainage (AMD) generation at the source. However, the hydrophilicity of TA passivation film and the complex coating process of organosilane-based passivators (high temperature conditions were required during the process carried out) may limit their further practical use. Therefore, to achieve the purpose of better coating treatment of pyrite under mild conditions, TA and γ-mercaptopropyltrimethoxysilane (PropS-SH) were introduced to synergistically passivate pyrite in this work. Electrochemistry tests and chemical leaching experiments both confirmed that PropS-SH-TA coated pyrite had better oxidation resistance than raw pyrite and single PropS-SH or TA coated pyrite. Additionally, the analyses of scanning electron microscopy (SEM) measurements and static water contact angle tests demonstrated that a scaly coating was formed on PropS-SH-TA coated pyrite surface, which may be the reason for the significant improvement of its surface hydrophobicity . Finally, the study on the film-forming mechanism of PropS-SH-TA composite passivator displayed that the benzoquinone derivatives formed by TA could copolymerize with PropS-SH through Michael addition or Schiff base reaction, which constructed a dense hydrophobic film on pyrite surface. The newly formed composite film could provide a better oxidation barrier for pyrite based on TA passivation film.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
MINERALS ENGINEERING
·
2022
·
IF 5.479
Sihui Wu,Jianjun Wang,Liming Tao,Ruihua Fan,Cong Wang,Wei Sun,Zhiyong Gao
In the flotation separation of chalcopyrite and pyrite, the commonly used high-lime process often causes problems such as losses of precious metals, blockage in pipelines and environmental pollution. In this study, acetylacetone (AA) was used as a novel collector to separate chalcopyrite from pyrite without adding limes. The flotation results indicate that AA can selectively separate chalcopyrite from pyrite without depressants at pH 9.0. Flotation kinetics and entrainment calculations show that compared with potassium ethyl xanthate (KEX), AA reduces pyrite entrainment and produces the concentrate with a higher Cu grade and a higher separation efficiency. Solution chemistry calculations show that enolate (AAE - ) and ketone (AAK) are the dominant species of AA at pH 9.0. Contact angle measurements, zeta potential measurements and Fourier transform infrared (FTIR) analysis indicate that the dominant species of AA chemically adsorb onto chalcopyrite surfaces at pH 9.0 while the adsorption on pyrite is minimal. Density functional theory (DFT) analysis reveals that the Fe atoms on chalcopyrite are the active sites interacting with AA to form six-membered ring complexes. The selective adsorption of AA relies on the spatial distribution and reactivity of Fe atoms on the commonly exposed cleavage surfaces of chalcopyrite and pyrite. After surface relaxation, a layer of Fe atoms appears on the outermost layer of chalcopyrite (1 1 2) surface, which is beneficial for the adsorption of AA species while a layer of S atoms for pyrite (1 0 0) surface. The Fe (III) on chalcopyrite (1 1 2) surface has a higher reactivity than the Fe (II) on pyrite (1 0 0) surface, leading to a higher adsorption energy of AA species on the chalcopyrite. Therefore, this acetylacetone-based lime-free process has a great potential for industrial application in the separation of chalcopyrite from pyrite.
研究领域:
矿物加工工程
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化学工程
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环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2024
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IF 8
Rui Liao,Jun Wang,Shichao Yu,Xin Sun,Shitong Liu,Baojun Yang,Guanzhou Qiu
Chalcopyrite has evolved into a crucial source of copper pollution, and xanthates inevitably coexisted with chalcopyrite in mine environments. However, the effect of xanthate on chalcopyrite bio-dissolution has not been illustrated yet. To fill this knowledge gap, the effect of potassium amyl xanthate (KAX) on copper release from chalcopyrite mediated by Acidithiobacillus ferrooxidans was investigated. The results revealed that KAX promoted chalcopyrite bio-dissolution, indicating more copper ions were released into the environment under these circumstances. KAX treatment groups displayed a lag period in ferrous ion oxidation, thereby providing a more favorable redox potential for chalcopyrite bio-dissolution. Bacterial adsorption experiments indicated the number of free cells increased with the addition of KAX, hence the Fe 3+ regeneration was accelerated. Elemental composition analyses indicated the addition of KAX was conducive to reducing the formation of passivation substance (S n 2− /S 0 ). Additionally, the reduced surface tension of solution in KAX treatment groups was beneficial for the oxidant diffusing into the pores and cracks of chalcopyrite. This study provided a better comprehension of the effect of xanthate on copper pollution caused by chalcopyrite bio-dissolution, as well as a step toward better guidance in preventing copper pollution at source.
研究领域:
微生物学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Shouxing He,Yaoguo Huang,Ming Wang,Yali Zhang,Linlin Chen,Yun Jia,Hui Liu
A novel chelating collector containing di-minerophilic group named 5-methyl isobutylxanthate-1,3,4-oxadiazole-2-thione (MIXODT) was first prepared and used for chalcopyrite flotation in this article. The flotation behavior of chalcopyrite with MIXODT as a collector was first evaluated by the micro-flotation experiments, and the results indicated that MIXODT showed better flotation capacity than sodium isobutyl xanthate (SIBX) for chalcopyrite recovery under acidic circumstances. Then hydrophobic mechanism of chalcopyrite was evaluated by wettability measurements, ζ-potential, interaction of MIXODT with metal ions, FTIR spectra and X-ray photoelectron spectroscopy (XPS). The wettability measurements proved that the surface hydrophobicity of chalcopyrite was improved significantly after MIXODT treatment. ζ-potential indicated that MIXODT chemisorbed on chalcopyrite surfaces. The experiment result of MIXODT with copper ions suggested that MIXODT had chemical interaction with Cu + and Cu 2+ ions. Moreover, FTIR and XPS spectra illustrated that the MIXODT-Cu complex was formed on chalcopyrite surface under the action of Cu-S and Cu-N bonds, accompanied with reduction of partial surface Cu(II) to Cu(I). Further, two different adsorption models of MIXODT-Cu + and MIXODT-Cu 2+ with “H” and “♬” types were proposed and predicted by DFT calculation respectively.
研究领域:
矿物加工工程
·
化学工程与技术
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2019
·
IF 3.315
Peilun Shen,Dianwen Liu,Xiaolin Zhang,Xiaodong Jia,Kaiwei Song,Dan Liu
Malachite is depressed during sulfidization flotation when excess sodium sulfide is added to it. Thus, this study investigated the role and mechanism of ammonium sulfate as a sulfidization promoter for eliminating the depression of excess S 2− via micro-flotation experiments, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), and inductively coupled plasma mass spectrometry (ICP-MS). Micro-flotation experiments revealed that malachite changed from a non-floating state to an easily floating state by (NH 4 ) 2 SO 4 addition prior to sulfidization with xanthate as the collector. The solution chemical reactions involving (NH 4 ) 2 SO 4 are the key to re-floating malachite. The surface properties of malachite were changed by (NH 4 ) 2 SO 4 , and these changes enhanced its flotation behavior. However, (NH 4 ) 2 SO 4 was not adsorbed onto the malachite surface in any form, as confirmed by the XPS analysis. (NH 4 ) 2 SO 4 has a dissolution on the malachite surface, causing lattice imperfections, which, in turn, provided the conditions necessary for subsequent adsorption of Cu(NH 3 ) n 2+ , S 2− (SH − ), and Cu 2+ on the malachite surface. Consequently, a layer or multilayer copper sulfide hydrophobic film formed on the malachite surface. Even the low-activity cylindrical surface of malachite was also covered with a stable copper sulfide film, resulting in improved malachite flotation in the presence of excess Na 2 S.
研究领域:
矿物加工工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Mining Science and Technology
·
2021
·
IF 4.084
Jinpeng Cai,Peilun Shen,Dianwen Liu,Xiaolin Zhang,Jianjun Fang,Chao Su,Xingcai Yu,Jiangli Li,Han Wang
In this work, the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated. Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM) and X-ray diffraction (XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface, but rather penetrates into the bulk to form covellite crystal (syn-CuS), creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation. Additionally, as demonstrated by X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF-SIMS) analyses, a redox reaction occurred during this process, and Cu(Ⅱ) onto the mineral surface was reduced to Cu(I). Correspondingly, reduced S 2- was oxidized to (S 2 ) 2- , (S n ) 2- , and even to deeper oxidation state S 0 , (S x O y ) n- and SO 4 2- . Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface, and provides enough raw material for crystal copper sulfide to grow, resulting in the formation of “flake-like” covellite with a better crystallinity. However, the floatability of azurite decreased dramatically under this condition, because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment, resulting in a decreased effective adsorption of collector onto azurite surfaces.
研究领域:
矿物学
·
浮选化学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2023
·
IF 4.8
Wenfei Wang,Xin Ma,Qiyang Lin,Hong Zhong,Zhiyong Gao,Shuai Wang
Xanthate, due to its superior collecting ability, is widely used in the field of minerals flotation. However, its weak selectivity and foul odor make it difficult to separate chalcopyrite from pyrite and reduce pollution. This work provides an efficient and odorless collector to selectively separate chalcopyrite from pyrite. Amide group was introduced into xanthate and an efficient and odorless xanthate derivative was designed, potassium O-(6-(butylamino)-6-oxohexyl) xanthate (PBAHX), to selectively separate chalcopyrite and pyrite. The flotation results showed that PBAHX exhibited superior selectivity, the separation index of PBAHX for chalcopyrite and pyrite is 2.65 while that of the traditional sodium isobutyl xanthate (SIBX) is 1.29, and enabled the separation of chalcopyrite and pyrite. The electronic-nose detection demonstrated that the odor intensity of PBAHX was lower than SIBX. Subsequently, “horizontal” adsorption model was formed for the adsorption of PBAHX on pyrite to explain the differences in flotation results. Besides, hydrogen bonds may be produced between collector molecules to dampen odor. PBAHX shows potential as a green and effective alternative to sulfide mineral flotation.
研究领域:
矿物加工
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Linquan Dai,Bo Feng,Mengyan Tang,Yuangan Chen
It is challenging to separate between molybdenite and chalcopyrite due to their comparable hydrophobic characteristics. Inorganic depressants were previously used to separate two minerals, but the results were unsatisfactory and polluted the environment. In this study, the molybdenite and chalcopyrite were separated using a highly effective and ecologically safe depressant, 2,4-Diamino-6-hydroxypyrimidine (DAHP). According to the single mineral experiment, chalcopyrite is totally depressed while molybdenite has superior floatability. The efficacy of DAHP as the depressant was validated by further artificially mixed mineral flotation experiments, indicating the possibility of separating chalcopyrite and molybdenite. The adsorption capacity experiment results showed that the adsorption capacity of DAHP on the surface of chalcopyrite was greater than that on the surface of molybdenite. Zeta potential experiment results show that DAHP is adsorbed on the surface of chalcopyrite and molybdenite through static electrostatic interactions . X-ray photoelectron spectroscopy (XPS) experiment results show that DAHP is mainly adsorbed on chalcopyrite surface through –NH 3 + group, which hinders the adsorption of kerosene. The electrostatic contact between DAHP and molybdenite has the least effect on kerosene adsorption. This study shows that DAHP has the potential to separate chalcopyrite and molybdenite as an efficient and environmentally friendly depressant.
研究领域:
矿物加工工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）