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Sulfur phase and sulfur removal in high sulfur-containing bauxite 被引量:15
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作者 胡小莲 陈文汨 谢巧玲 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1641-1647,共7页
The sulfur phase in high sulfur-containing bauxite was studied by an X-ray diffraction analysis and a chemistry quantitative analysis.The methods for the removal of different shaped sulfur were also discussed.The resu... The sulfur phase in high sulfur-containing bauxite was studied by an X-ray diffraction analysis and a chemistry quantitative analysis.The methods for the removal of different shaped sulfur were also discussed.The results show that sulfur phases in high sulfur-containing bauxites exist in the main form of sulfide sulfur (pyrite) or sulfate sulfur,and the main sulfur forms of bauxites from different regions are not the same.Through a combination of an X-ray diffraction analysis and a chemistry quantitative analysis,the sulfur phases of high sulfur-containing bauxite could be accurately investigated.Deciding the main sulfur form of high sulfur-containing bauxite could provide theoretical instruction for choosing methods for the removal of sulfur from bauxite,and an oxidizing-roasting process is an effective way to remove sulfide sulfur from high sulfur-containing bauxite,the content of S^2-in crude ore in the digestion liquor is above 1.7 g/L,but in the roasted ore digestion liquor,it is below 0.18 g/L.Using the sodium carbonate solution washing technology to wash bauxite can effectively remove sulfate sulfur,the content of the total sulfur in ore is lowered to below 0.2% and can meet the production requirements for the sulfur content. 展开更多
关键词 high sulfur-containing bauxite sulfur phase oxidizing-roasting sodium carbonate solution washing technology
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Highly Efficient and Selective Removal of Pb(II) ions by Sulfur-Containing Calcium Phosphate Nanoparticles 被引量:1
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作者 龚成云 耿志刚 +3 位作者 董安乐 叶新新 汪国忠 张云霞 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第5期607-616,I0002,共11页
A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate (SCP) nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The ... A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate (SCP) nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The resulting SCP exhibited a noticeable enhanced performance for Pb(II) removal in comparison with hydroxyapatite (HAP), being capable of easily reducing 20 ppm of Pb(II) to below the acceptable standard for drinking water within less than 10 min. Remarkably, the saturated removal capacities of Pb(II) on SCP were as high as 1720.57 mg/g calculated by the Langmuir isotherm model, exceeding largely that of the previously reported absorbents. Significantly, SCP displayed highly selective removal ability toward Pb(II) ions in the presence of the competing metal ions (Ni(II), Co(II), Zn(II), and Cd(II)). Further investigations indicated that such ultra-high removal efficiency and preferable affinity of Pb(II) ions on SCP may be reasonably ascribed to the formation of rodlike hydroxypyromorphite crystals on the surface of SCP via dissolution-precipitation and ion exchange reactions, accompanied by the presence of lead sulfide precipitates. High removal efficiency, fast removal kinetics and excellent selectivity toward Pb(II) made the obtained SCP material an ideal candidate for Pb(II) ions decontamination in practical application. 展开更多
关键词 sulfur-containing calcium phosphate Pb(II) ions Selective removal
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A review of gold extraction using noncyanide lixiviants: Fundamentals, advancements, and challenges toward alkaline sulfur-containing leaching agents 被引量:11
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作者 Chun-bao Sun Xiao-liang Zhang +1 位作者 Jue Kou Yi Xing 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第4期417-431,共15页
Alkaline sulfur-containing lixiviants,including thiosulfate,polysulfides,and alkaline sulfide solutions,stand out as a promising class of alternatives to cyanide because of their low toxicity,high efficiency,and stron... Alkaline sulfur-containing lixiviants,including thiosulfate,polysulfides,and alkaline sulfide solutions,stand out as a promising class of alternatives to cyanide because of their low toxicity,high efficiency,and strong adaptability.In this paper,we summarized the research progress and remaining challenges in gold extraction using these noncyanide reagents.After a brief introduction to the preparation method,the transformation process of various sulfur-containing species in alkaline solutions was discussed.Thereafter,some insights into the mechanism of gold leaching in alkaline sulfur-containing solutions were presented from different aspects,including thermodynamics analysis,electrochemical dissolution,and leaching kinetics.Moreover,recent progress in in-situ generation of sulfur-containing anions from gold-bearing sulfide minerals was outlined as well.Gold passivation caused by sulfur species was discussed in particular because it is considered the greatest challenge facing sulfur-containing leaching systems.Alkaline sulfur-containing lixiviants are expected to serve as alternatives in industrial applications of gold extraction,particularly for refractory gold ores containing copper and carbonaceous matter. 展开更多
关键词 GOLD extraction sulfur-containing lixiviants degradation in-situ generation PASSIVATION
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pH variation mechanism of high sulfur-containing bauxite 被引量:2
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作者 陈兴华 胡岳华 +2 位作者 李旺兴 陈湘清 曹学锋 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期2909-2913,共5页
In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing ... In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite(Fe S2), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air. 展开更多
关键词 high sulfur-containing bauxite PYRITE acidification mechanism
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Synthesis and Characterization of New Schiff Bases Formed by Condensation of 2,9-Phenathroline-1,10-dialdehyde with Sulfur-Containing Amines 被引量:2
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作者 Md. Arifuzzaman Mohammad R. Karim +2 位作者 Tasneem A. Siddiquee Aminul H. Mirza Mohamad A. Ali 《International Journal of Organic Chemistry》 2013年第1期81-86,共6页
Four new Schiff bases of 1,10-phenanthroline-2,9-dicarboxaldehyde with sulfur-containing amines such as 2-mercaptoaniline, S-alkyl/aryl dithiocarbazates and thiosemicarbazide have been synthesized and characterized by... Four new Schiff bases of 1,10-phenanthroline-2,9-dicarboxaldehyde with sulfur-containing amines such as 2-mercaptoaniline, S-alkyl/aryl dithiocarbazates and thiosemicarbazide have been synthesized and characterized by spectroscopic and X-ray crystallographic techniques. A comparative study of the methods of synthesis has been made using both traditional and microwave techniques. A significant reduction in reaction time has been observed when the microwave method was used. In some of the reactions, the yields also increased significantly. 展开更多
关键词 PHENANTHROLINE SCHIFF Base Dithiocarbazide sulfur-containing Antibaterial
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QSPR Study on the Boiling Points of Some Oxygenand Sulfur-containing Organic Compounds 被引量:1
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作者 陈建挺 刘红玲 +2 位作者 王甫洋 于红霞 李定龙 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第12期1561-1568,共8页
Structural and thermodynamic parameters of 56 oxygen-containing and 56 sulfur- containing organic compounds were computed at the B3LPY/6-311G** level using density functional theory (DFT) method. Furthermore,the d... Structural and thermodynamic parameters of 56 oxygen-containing and 56 sulfur- containing organic compounds were computed at the B3LPY/6-311G** level using density functional theory (DFT) method. Furthermore,the dependent equations between the experimental data of boiling points (Tb) and theoretical parameters were proposed with SPSS12.0 for windows software,whose correlation coefficients R2 are 0.933 and 0.945. These dependent equations were validated by cross-validation method (q2 are 0.923 and 0.929,respectively). VIF (variance inflation factors) and t-value methods were also used to verify the significance and self-correlationship of each variable. Results indicate that our dependent equation exhibits good prediction ability,and molecular polarizability (α) is the main factor affecting the Tb of oxygen- and sulfur-containing organic compounds. To our interest,obvious dependence could also be found among the oxygen- and sulfur-containing organic compounds' experimental data of boiling points (Tb) with R^2 of 0.857. 展开更多
关键词 boiling points oxygen-containing organic compounds sulfur-containing organic compounds quantitative structure-property relationship (QSPR) DFT
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Catalytic kinetics of dimethyl ether one-step synthesis over CeO_2–CaO–Pd/HZSM-5 catalyst in sulfur-containing syngas process 被引量:1
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作者 Ruizhi Chu Wenxin Hou +4 位作者 Xianliang Meng Tingting Xu Zhenyong Miao Guoguang Wu Lei Bai 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第12期1735-1741,共7页
CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of Ce... CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of CeO_2–CaO–Pd/HZSM-5 was investigated to ensure that the kinetics experimental results were not significantly influenced by induction period and catalytic deactivation. A large number of kinetic data points(40 sets) were obtained over a range of temperature(240–300 °C), pressure(3–4 MPa), gas hourly space velocity(GHSV)(2000–3000 L·kg^(-1)·h^(-1)) and H_2/CO mole ratio(2–3). Kinetic model for the methanol synthesis reaction and the dehydration of methanol were obtained separately according to reaction mechanism and Langmuir–Hinshelwood mechanism. Regression parameters were investigated by the method combining the simplex method and Runge–Kutta method. The model calculations were in appropriate accordance with the experimental data. 展开更多
关键词 CeO_2–CaO –Pd/HZSM-5 catalyst DME One-step synthesis Catalytic kinetics sulfur-containing syngas
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An Innovative Method for the Determination of Sulfur-containing Compounds by Vapor Molecular Absorption Spectrometry
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作者 Duan Yixiang, Zhang Hanqi, Liu Xinwei, Wang Lishuang and Jin Qinhan (Department of Chemistry, Jilin University, Changchun) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1991年第4期245-246,共2页
Since the most sensitive resonance lines of nonmetallic elements are situated in vacuum ultraviolet region (below 190 nm), they can not be directly determined with a common AAS instrument covering the spectral range... Since the most sensitive resonance lines of nonmetallic elements are situated in vacuum ultraviolet region (below 190 nm), they can not be directly determined with a common AAS instrument covering the spectral range from 190 to 700 nm. The molecular absorption spectrometry is often used for the determination of nonmetallic elements. Syty et al. used vapor molecular absorption spectrometry(VMAS) to determine the sulfur dioxide and sulfide, in which a hydrogen hollow cathode lamp was used as a continuum source to determine SO;at 210 nm and a deuterium arc 展开更多
关键词 Molecular absorption SPECTROMETRY sulfur-containing compound
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The Synthesis of New Sulfur-containing Chiral Macrocyclic Ligands
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作者 Xiao Ling ZHANG Jing Song YOU +1 位作者 Xing Shu LI Ru Gang XIE(Department of Chemistry, Sichuan Union University, Chengdu 610064) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第10期853-854,共2页
Five new chiral sulfur-containing macrocyclic ligands which can be used in chiral recognition to guests have been synthesized and characterized
关键词 OCH LI CL The Synthesis of New sulfur-containing Chiral Macrocyclic Ligands
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Effect of reagent films on coupling relationship between glass surface and particles 被引量:1
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作者 李明 吴超 +1 位作者 刘一静 闫晖 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2799-2805,共7页
The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significant... The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significantly changed by the reagent films. There were no evident rules between the average size of particles and sampling time interval, the placing angle and reagent concentration. The average particle size on the surface coated by composite reagent (2-3 μm) was smaller than that on the single reagent coated surface, while the largest particle size (4-5 μm) was observed on the surface coated with the Tween 60. The experiment also demonstrated that the best adhesive performance was obtained on the surface which was coated with 0.5% SDBS and 0.5% fluorocarbon composite reagents. The experiment results indicated that each reagent had a certain optimum adhesive range to the particle. The composite reagents with different proportion of single reagents exhibited some particular physical and chemical properties, which could effectively change the adhesive performance between the solid surface and the particles. 展开更多
关键词 micro-particles ADHESION glass surface reagent film size distribution
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芬顿试剂(Fenton's reagent法降解对苯二酚和工业废水 被引量:4
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作者 常文贵 谢红璐 《渤海大学学报(自然科学版)》 CAS 2004年第1期15-18,共4页
可溶性亚铁盐和H2O2的组合称为芬顿试剂(Fenton’s reagent),是一种氧化能力很强的氧化剂,常用于废水的净化处理。本文以对苯二酚为代表物,探讨用Fenton试剂氧化的反应条件,并用最佳的实验条件处理工业废水,90分钟工业废水的COD去除率可... 可溶性亚铁盐和H2O2的组合称为芬顿试剂(Fenton’s reagent),是一种氧化能力很强的氧化剂,常用于废水的净化处理。本文以对苯二酚为代表物,探讨用Fenton试剂氧化的反应条件,并用最佳的实验条件处理工业废水,90分钟工业废水的COD去除率可达71.6%。 展开更多
关键词 芬顿试剂 羟基自由基 废水处理 COD去除率 苯二酚 工业废水
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Preparation of ZnO Nanoparticles and Photocatalytic H2 Production Activity from Different Sacrificial Reagent Solutions
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作者 彭天右 吕红金 +1 位作者 曾鹏 张晓虎 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第4期464-470,I0004,共8页
ZnO nanoparticles were synthesized via a direct precipitation method followed by a hetero- geneous azeotropic distillation and calcination processes, and then characterized by X-ray power diffraction, scanning electro... ZnO nanoparticles were synthesized via a direct precipitation method followed by a hetero- geneous azeotropic distillation and calcination processes, and then characterized by X-ray power diffraction, scanning electron microscopy, transmission electron microscopy, and ni- trogen adsorption-desorption measurement. The effects of Pt-loading amount, calcination temperature, and sacrificial reagents on the present ZnO suspension were investigated, photocatalytic H2 evolution efficiency from the The experimental results indicate that ZnO rianoparticles calcined at 400℃ exhibit the best photoactivity for the H2 production in comparison with the samples calcined at 300 and 500℃, and the photoeatalytie H2 production efficiency from a methanol solution is much higher than that from a triethanolamine solution. It can be ascribed to the oxidization of methanol also contributes to the H2 production during the photochemical reaction process. Moreover, the photocatalytic mechanism for the H2 production from the present ZnO suspension system containing methanol solution is also discussed in detail. 展开更多
关键词 Photocatalytic hydrogen production ZnO Photocatalytic activity Sacrificial reagent
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改良“Trizol Reagent”试剂提取总RNA方法 被引量:1
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作者 李少玲 袁青 高英茂 《山东医科大学学报》 2001年第3期196-196,共1页
关键词 Trizo reagent 异硫氢酸胍 RNA 提取
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用Lipofectin Reagent转染猪子宫上皮细胞 被引量:1
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作者 吴惠贤 《畜牧兽医学报》 CAS CSCD 北大核心 1993年第2期175-180,共6页
本文用Lipofectin Reagent作为转染细胞的间型脂质,使Liposome与SV40 ts A209 DNA形成一种混合物转染猪子宫上皮细胞。此法比用磷酸钙和二乙氨乙基葡聚糖转染细胞的方法简单,高效、重复性好。转染后的猪子宫上皮细胞形状和大小略有改变... 本文用Lipofectin Reagent作为转染细胞的间型脂质,使Liposome与SV40 ts A209 DNA形成一种混合物转染猪子宫上皮细胞。此法比用磷酸钙和二乙氨乙基葡聚糖转染细胞的方法简单,高效、重复性好。转染后的猪子宫上皮细胞形状和大小略有改变;对温度敏感,用相同培养液培养7天,在33℃条件下细胞的生长速度是在40℃时的5倍. 展开更多
关键词 子宫 上皮细胞 转染 DNA
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Mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes from stone coal 被引量:23
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作者 Fei Wang Yi-Min Zhang +4 位作者 Jing Huang Tao Liu Yi Wang Xiao Yang Jie Zhao 《Rare Metals》 SCIE EI CAS CSCD 2013年第1期57-62,共6页
The mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes were researched by comparing the blank extraction with the extraction with calcium fluoride as aid-leaching reagent. The lea... The mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes were researched by comparing the blank extraction with the extraction with calcium fluoride as aid-leaching reagent. The leaching experiments were carried out under the conditions of 95 ~C, 6 h, 1.5 ml.g-1, 15 vol % H2SO4, and 5 % calcium fluoride (mass ratio of CaF2 to stone coal). The concentrations of hydrogen ion were adjusted from initial 1.82 and 4.79 mol.L-1 to the pH of 1.80 4- 0.05 by 200 g.L-1 lime milk, respectively. The solvent extraction experiments were carded out under the organic phase using 15 vol% D2EHPA, 5 vol% TBP, and 80 vol% sulfonated kerosene and O/A phase ratio of 1/4. The leaching rate of vanadium and six-stage countercurrent solvent extraction rate of vanadium can be remarkably improved from 66.71 to 92.97 % and 81.15 to 98.81%, respectively, when calcium fluoride was added as aid-leaching reagent. In the leaching process, fluorine can enhance the breakage of the structure of vanadium-bearing minerals. Meanwhile, fluoride ion can combine with iron ion to generate acid-insoluble iron fluoride hydrate (Fe2Fs.7H20) and consume all ferric ions and a portion of ferrous ions. In adjusting pH value process, the massive impurities are decreased to form KA1SO4 and FeA1Fs. In solvent extraction process, fluorine can prevent the formation of ferric hydroxide colloids and eliminate the formed unstable ferric hydroxide colloids and the silicon-containing colloids to promote the sufficient contact between the aqueous phase and the organic phase and the sufficient reaction. 展开更多
关键词 VANADIUM Stone coal Aid-leaching reagent Calcium fluoride MECHANISMS
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Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning 被引量:27
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作者 Maha A. Tony Y. Q. Zhao Aghareed M. Tayeb 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第1期101-105,共5页
The use of Fenton's reagent (Fe^2+/H2O2) and Fenton-like reagents containing transition metals of Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), and Mn(Ⅱ) for an alum sludge conditioning to improve its dewaterability was invest... The use of Fenton's reagent (Fe^2+/H2O2) and Fenton-like reagents containing transition metals of Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), and Mn(Ⅱ) for an alum sludge conditioning to improve its dewaterability was investigated. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton's reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time (CST) reduction efficiency of 47% can be achieved under test conditions of Fe^2+/H2O2 = 20/125 mg/g DS (dry solid) and pH 6.0. The observation of floc-like particles after Fenton's reagent conditioning of alum sludge suggested that the mechanism of Fenton's reagent conditioning was different from that of polymer conditioning. In spite of the lower efficiency in the CST reduction of Fenton's reagent in alum sludge conditioning compared to that of polymer conditioning, Fenton's reagent offers a more environmentally safe option. Tiffs study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy. 展开更多
关键词 alum sludge CONDITIONING Fenton and Fenton-like reagents organic polymers cost estimate
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Reagent types and action mechanisms in ilmenite flotation:A review 被引量:7
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作者 Jiaozhong Cai Jiushuai Deng +5 位作者 Liang Wang Mingzhen Hu Hongxiang Xu Xiaoan Hou Bozeng Wu Shimei Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第9期1656-1669,共14页
Ilmenite is an essential mineral for the extraction of titanium.Conventional physical separation methods have difficulty recovering fine ilmenite,and dressing plants have begun applying flotation to recover ilmenite.T... Ilmenite is an essential mineral for the extraction of titanium.Conventional physical separation methods have difficulty recovering fine ilmenite,and dressing plants have begun applying flotation to recover ilmenite.The interaction of reagent groups with Ti and Fe sites on the ilmenite surface dramatically influences the ilmenite flotation.However,the investigation on Fe sites has received more attention because the activity of Ti is lower than that of Fe.For the activators on ilmenite flotation,most are metal ions but typically lead ions.The metal ions of activators promote ilmenite flotation by increasing the active sites on the ilmenite surface.Combined reagents have a better selective separation of ilmenite than single reagents due to their synergistic effect.Combining the lead ion(Pb^(2+))and the benzyl hydroxamic acid(BHA)into a Pb-BHA complex has a marked effect on ilmenite flotation,which puts forward a new idea of developing combined reagents for ilmenite flotation.This review considers reagent types and action mechanisms in ilmenite flotation.On the basis of the analysis of previous research,a brief future outlook of reagent types and action mechanisms in ilmenite flotation is also proposed in this study. 展开更多
关键词 ILMENITE FLOTATION reagent action mechanism combined reagents
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Diagnosis of spontaneous bacterial peritonitis: An update on leucocyte esterase reagent strips 被引量:16
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作者 Anastasios Koulaouzidis 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第9期1091-1094,共4页
Ascites remain the commonest complication of decompensated cirrhosis. Spontaneous bacterial peritonitis (SBP) is defined as the infection of ascitic fluid (AF) in the absence of a contiguous source of infection and/or... Ascites remain the commonest complication of decompensated cirrhosis. Spontaneous bacterial peritonitis (SBP) is defined as the infection of ascitic fluid (AF) in the absence of a contiguous source of infection and/or an intraabdominal inflammatory focus. An AF polymorphonuclear (PMN) leucocyte count ≥ 250/mm 3 -irrespective of the AF culture resultis universally accepted nowadays as the best surrogate marker for diagnosing SBP. Frequently the results of the manual or automated PMN count do not reach the hands of the responsible medical personnel in a timely manner. However, this is a crucial step in SBP management. Since 2000, 26 studies (most of them published as full papers) have checked the validity of using leukocyte esterase reagent strips (LERS) in SBP diagnosis. LERS appear to have low sensitivity for SBP, some LERS types more than others. On the other hand, though, LERS have consistently given a high negative predictive value (> 95% in the majority of the studies) and this supports the use of LERS as a preliminary screening tool for SBP diagnosis. Finally, an AF-tailored dipstick has been developed. Within the proper setting, it is set to become the mainstream process for handling AF samples. 展开更多
关键词 PERITONITIS Leukocytes ESTERASES DIAGNOSIS reagent strips BACTERIAL
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Optimization of efficient stable reagent of alkaline thiourea solution for gold leaching 被引量:5
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作者 王云燕 柴立元 +2 位作者 闵小波 何德文 彭兵 《Journal of Central South University of Technology》 EI 2003年第4期292-296,共5页
Na2SiO3 and Na2SeO3 were chosen as stable reagents of alkaline thiourea solution substituting Na2SO3, according to the structure-property relationship between the stability of alkaline thiourea and the structure of th... Na2SiO3 and Na2SeO3 were chosen as stable reagents of alkaline thiourea solution substituting Na2SO3, according to the structure-property relationship between the stability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of the stable reagents on stability of alkaline thiourea was investigated. The results show that contrary to Na2SeO3, Na2SO3 and Na2SiO3 affect the stability of alkaline thiourea solution remarkably. The stable effect of Na2SiO3 on alkaline thiourea is obviously better than that of Na2SO3. The stable reagents Na2SO3 and Na2SiO3 decrease the decomposition rate of alkaline thiourea solution greatly, and the decomposition rate of alkaline thiourea reduces from (72.5%) to (33.8%) with addition of (0.3 mol·L-1) Na2SiO3. Dissolution currents of gold in the alkaline thiourea solution containing Na2SO3 and Na2SiO3 are (2.0) (mA·cm-2) and (3.5) (mA·cm-2) at the potential of 0.42 V, respectively, and Na2SO3 is consumed excessively due to the oxidation reaction of Na2SO3 occurring in the studied potential range. Na2SiO3 is an efficient stable reagent of alkaline thiourea solution, and gold dissolution is accelerated much more obviously by Na2SiO3 than by Na2SO3. 展开更多
关键词 ALKALINE THIOUREA gold LEACHING STABLE reagent NA2SIO3 Na2SO3 Na2SeO3
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Novel Synthetic Method for the Vilsmeier-Haack Reagent and Green Routes to Acid Chlorides, Alkyl Formates, and Alkyl Chlorides 被引量:12
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作者 Yoshikazu Kimura Daisuke Matsuura 《International Journal of Organic Chemistry》 2013年第3期1-7,共7页
An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byprod... An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions. 展开更多
关键词 Phthaloyl DICHLORIDE Vilsmeier-Haack reagent ACID Chlorides ALKYL FORMATES ALKYL Chlorides
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