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The reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization of vinyl acetate mediated by xanthate

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Chinese Chemical Letters 2009年第6期20卷 733-737页

作者： Bo Jiang Qing Hua Zhang Xiao Li Zhan Feng Qiu Chen Department of Chemical and Biochemical Engineering Zhejiang University Hangzhou 310027 People's Republic of China

The reversible addition-fragmentation chain transfer （RAFT） miniemulsion polymerization of vinyl acetate （VAc） mediated by methyl （methoxycarbonothioyl） sulfanyl acetate （MMSA） was carried out. The results showed that polymerizations initiated by AIBN and KPS proceeded in a controlled way. The RAFT miniemulsion polymerization of VAc initiated by KPS showed the shorter inhibition period, higher propagation rate coefficient and final conversion than those in experiment initiated by AIBN. When the monomer conversion reached 25%, the polydispersity index （PDI） of polymer became broad, which was related to chain transfer reaction in RAFT miniemulsion of VAc.

关键词： Xinyl acetate xanthate Reversible addition-fragmentation chain transfer Miniemulsion

ON-LINE DETERMINATION OF REMAINED xanthate CONCENTRATION IN PULP

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Journal of Central South University 1998年第1期10卷 12-14页

作者： Huang Ning Mao Anzhang Wang Dianzuo① Li Bodan Sun Shuiyu(Department of Mineral Engineering, Central South University of Technology,Changsha 410083,China) 1. Department of Mineral Engineering Central South University of Technology 410083 Changsha China 2. Beijing General Nonferrous Research Institute 100044 Beijing China

The construction principle of the system for determination of xanthate concentration,which consists of an Ionselective electrode(ISE) and a microprocessor based SDI analyzer,was described in the *** performances of the developed system were discussed in *** results both detected in solutions and in sulfide mineral flotation system were given; also the results by ultraviolet spectrometry were compared with those by the developed system.

关键词： xanthate online determination ion selective electrode

Microthermokinetic study of xanthate adsorption on impurity-doped galena

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Transactions of Nonferrous Metals Society of China 2016年第1期26卷 272-281页

作者：蓝丽红陈建华李玉琼蓝平杨卓艾光湧广西民族大学化学化工学院广西高校化学与生物转化过程新技术重点实验室南宁530006 广西大学资源与冶金学院南宁530004

Six kinds of galena with different impurities were synthesized and the effects of impurities on the floatability of galena were investigated. The thermodynamic and kinetic parameters on the galena surface were measured using microcalorimetry, and the adsorption configuration and energy of butyl xanthate on the surfaces of galena with different impurities were simulated by density functional theory. Flotation experiments showed that Ag and Bi significantly promoted the recovery of galena, while Zn, Sb, Mn, and Cu reduced the recovery of the flotation. Microthermokinetic results indicated that the absolute value of xanthate adsorption heat was directly proportional to the flotation recovery of galena. Adsorption heat and reaction rate coefficients of xanthate on galena containing Ag or Bi were larger than those on pure galena, but smaller on galena containing Cu or Sb. Additionally, the relationship between the heat of unsaturated adsorption of xanthate and the adsorption energy of impurity atom on galena surface was investigated.

关键词： galena impurity effect floatation xanthate adsorption microcalorimetry density functional theory

Occurrence of lead and silver minerals and their interaction with xanthate in slurry of zinc electrolysis anode slime

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Transactions of Nonferrous Metals Society of China 2012年第7期22卷 1794-1800页

作者：向平冯其明朱阳戈邓杰龙涛钮因健中南大学资源加工与生物工程学院长沙410083 株洲市湘麒资源综合利用研究所株洲412005

The background pulp potential of zinc anode slime,and its influence on the occurrence of lead,silver and xanthate,were investigated with thermodynamic *** thermodynamic conclusion and XRD analysis pointed out that in zinc anode slime,the thermodynamically stable compound of xanthate is dixanthogen,anglesite is the only mineral of lead,and kerargyrite is one of silver minerals *** tests on single minerals of anglesite and kerargyrite in sulfuric acid solution by amyl dixanthogen indicated that dixanthogen has a much stronger collecting ability to kerargyrite than to *** dynamic simulation indicated that amyl dixanthogen can only be adsorbed on the surface of kerargyrite in the presence of SO42-.The FTIR tests also verified the selective adsorption of amyl dixanthogen on the surface of kerargyrite in the presence of SO42-.

关键词： zinc electrolysis anode slime anglesite kerargyrite xanthate adsorption

THE SEPARATION AND DETERMINATION OF xanthateS USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

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Transactions of Nonferrous Metals Society of China 1991年第1期1卷 89-95页

作者： Zhou Chunshan Bahr Albert Schwedt Georg Central South University of Technology Changsha 410083China Technical University of Clauslhal Clausthal-ZellerfeldGermany

Three HPLC methods for the separation and determination of xanthate mixtures are *** chromatographic behaviours,advantages and application ranges of various:methods have been discussed in detail.A calculation method for determining the results of individual xanthates from the complicated chromatographic peaks of xanthate mixtures is *** limits of detection are 0.15-2.0ng.

关键词： xanthate dixanthogen collector liquid chromatography

Electrodeposition of dixanthogen on surface of pyrrhotite electrode

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中国有色金属学会会刊：英文版 2000年第S1期10卷 61-63页

作者：覃文庆邱冠周徐竞 Cent S Univ Technol Dept Mineral Engn Changsha 410083 Peoples R China

Electrochemical behavior of pyrrhotite in the presence of xanthate solution was studied. Cycle voltammogram scan, chronopotentiometry and rotating disc electrode measurements were used to analyze the electrodeposit process of dixanthogen on the surface of pyrrhotite electrode. Experimental results demonstrate that the first step of electrodeposit is electrochemical adsorption of xanthate ion, and then one xanthogennic ion adsorbed integrates itself with another free xanthate ion to form dixanthogen. Using galvanostatic technique, the electrochemical dynamics equation of the electrodeposit process of dixanthogen on the surface of pyrrhotite electrode was set up. It can quantitatively describe the oxidation process of xanthate on pyrrhotite surface.

关键词： pyrrhotite xanthate electrochemistry of flotation

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

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Journal of Central South University 1998年第1期10卷 5-7页

作者： Ou Leming Feng Qiming Chen Jin(Department of Mineral Engineering, Central South University of Technology, Changsha 410083,China) 1. Department of Mineral Engineering Central South University of Technology 410083 Changsha China

In the thermodynamics, for flotation separation of the SbAs 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 SbAs bulk concentrate flotation separation and UVspectrophotometic analysis. The electrochemical separation of SbAs bulk concentrate has been carried out. qualified concentrate has been obtained. Sbconcentrate contains Sb 4944 %, As 044 %, Sbrecovery is 8783 % and Asconcentrate contains As 1096 %, Asrecovery is 9466 %.

关键词： flotation stibnite arsenopyrite butyl xanthate pulp electrochemistry

Synthesis and Crystal Structure of Bismuth（Ⅲ） Complexes Bi（1,10-phen）[S2CN（CH3）2]2（NO3）, {Bi（S2COCH3）[S2CNC6Hs（CH3）]2}2 and [Bi（S2CNBu2）2（CH3OH）（NO3）]∞

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Chinese Journal of Chemistry 2005年第12期23卷 1631-1636页

作者：尹汉东王传华邢秋菊 Department of Chemistry Liaocheng University Liaocheng Shandong 252059 China

Three bismuth（Ⅲ） complexes Bi（1,10-phen）[S2CN（CH3）2]2（NO3）（1）, {Bi（S2COCH3）[S2CNC6Hs（CH3）]2}2 （2） and [Bi（S2CNBu2）2（CH3OH）（NO3）]∞ （3） were synthesized and characterized by elemental analysis and IR spectra. Their crystal structures were determined by X-ray single crystal diffraction analysis. Studies show that complex 1 has a monomeric structure with the central bismuth atom eight-coordinated in a capped distorted pentagonal bipyramidal geometry. The complex 2 takes centrosymmetric dimeric structure and the bismuth atoms are seven-coordinated in distorted pentagonal bipyramidal *** complex 3, the bismuth atoms are seven-coordinated in distorted pentagonal bipyramidal geometry by bridging nitrate O atoms and the resulting structure is onedimensional infinite chain polymer.

关键词： bismuth(Ⅲ) complex dithiocarbamate xanthate crystal structure

Effect of potential on characteristics of surface film on natural chalcopyrite

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Transactions of Nonferrous Metals Society of China 2011年第8期21卷 1880-1886页

作者：俞娟杨洪英范有静东北大学材料与冶金学院沈阳110004 东北大学理学院沈阳110004

Electrochemical behavior of natural chalcopyrite in electrolyte solution containing 5×10？4 mol/L ethyl xanthate, and the effect of potential on the composition and characteristics of surface film were studied by cyclic voltammetry （CV）, scanning electron microscopy （SEM） and electrochemical impedance spectroscopy （EIS）. The adsorption of xanthate （X？） occurred on the mineral surface at open-circuit potential （OCP）. In the potential range from -0.11 to 0.2 V, the electrochemical reaction related to the formation of the hydrophobic film of dixanthogen （X2） occurred on natural chalcopyrite surface. This surface film had high coverage and large thickness at the potential of 0 V, but it had low coverage and small thickness at the potentials of 0.1 V and 0.2 V. Electrochemical activation started to occur when the potential was higher than 0.2 V, and the film of X2 transformed to plenty of Cu（Ⅱ） and Fe（Ⅲ） oxygen-containing species which had the porous and loose characteristics.

关键词： potential chalcopyrite surface film xanthate