Sulfur phase and sulfur removal in high sulfur-containing bauxite

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.

Highly Efficient and Selective Removal of Pb（II） ions by Sulfur-Containing Calcium Phosphate Nanoparticles

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.

A review of gold extraction using noncyanide lixiviants: Fundamentals, advancements, and challenges toward alkaline sulfur-containing leaching agents

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.

Distribution and Significance of Methyl Steranes in Bohai Bay Basin, East China

31 samples of shales and mudstones developed in reducing hypersaline andfreshwater setting and 20 oil samples of Bamianhe oilfield, Bohai Bay basin were collected for adetailed study of petroleum system. Composition and distribution, especially significance ofsteroids, are discussed as a part of those. Abundant steroidal biomarkers, including C_(27-29)regular Steranes, C_(28-30) 4-methyl steranes, di-nosteranes and aromatic steranes, were detected.Results show that the composition and distribution of the steroids in samples studied are functionsof thermal maturity, organic source, paleoenvironment and lithology of potential source rocks.Alga-rich Es_4 shales (brackish water) developed in the south slope of depocenter (Niuzhuang sag)were found particularly rich in steroidal biomarkers including C_(30) 4-methyl steranes anddinosteranes. Es_3 mudstones (fresh water) were found devoid of dinosteranes. Distribution patternsof regular steranes are completely different from methyl steranes indicating different origins ofthe specific compounds of the fractioa Diagnostic distribution of steranes in rock extracts ofdiverse intervals makes the compounds to be essential indictors of source-rock tracing. Methylsteranes prove to be much more useful in oil-source rock correlation than regular steranes. Resultsalso show that alga-rich Es_4 shales located in the south slope are not likely the primary sourcerock responsible for the oils discovered based on the composition and distribution of steroids.

pH variation mechanism of high sulfur-containing bauxite

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.

Synthesis and Characterization of New Schiff Bases Formed by Condensation of 2,9-Phenathroline-1,10-dialdehyde with Sulfur-Containing Amines

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.

QSPR Study on the Boiling Points of Some Oxygenand Sulfur-containing Organic Compounds

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.

Catalytic kinetics of dimethyl ether one-step synthesis over CeO_2–CaO–Pd/HZSM-5 catalyst in sulfur-containing syngas process

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.

An Innovative Method for the Determination of Sulfur-containing Compounds by Vapor Molecular Absorption Spectrometry

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

Maturity effects on steranes of source rocks in Lishu fault depression,Songliao Basin

Geochemical analysis results of 30 source rock samples from Lishu fault depression in Songliao Basin show that samples are compositionally similar and represent a uniform organic facies.Differential distribution of steranes among the samples is due to rank,with vitrinite reflectances(Ro)ranging from 0.65 to 1.61%.In the maturity stage(Ro=0.65-1.20%),the absolute concentrations of steranes increase,which is affected by kerogen degradation,whereas the pyrolysis of high mature source(Ro=1.20-1.61%)show a decrease in the abundance of steranes.Simultaneously,the parameters of steranes vary greatly with maturity.Decrease of prognane/regular sterane value with the increase of maturity suggests that pregnane is not a product of regular steranes pyrolysis.The ratios of C27/C29regular sterane gradually increase,while the value of C29-20S/(20S+20R)and αββ/(αββ+ααα)decrease at high maturity stage,which is associated with the difference in the thermostability of steranes involved.This reversed trend can be used to determine the high-maturity stage of source rocks.Whereas the values of rearranged steranes/regular steranes in source rocks show an apparent positive correlation with maturity,it,therefore,appears to be particularly useful for maturity assessment at elevated levels.

The Synthesis of New Sulfur-containing Chiral Macrocyclic Ligands

Five new chiral sulfur-containing macrocyclic ligands which can be used in chiral recognition to guests have been synthesized and characterized

原油中C_(19-49)长链三环萜烷系列及其地球化学意义——以柴达木盆地西部英西地区原油为例

【目的】为了确定柴达木盆地西部英西地区古近系深部储层(E)原油的热演化程度和成因类型,【方法】利用色谱—质谱(GC-MS)和色谱—质谱—质谱(GC-MS-MS)技术,对其中的各类生物标志物、烷基菲和金刚烷类化合物的分布与组成特征进行了系统分析。【结果与讨论】分析结果表明该地区原油中正构烷烃系列均具有明显的偶碳优势,Pr/Ph比值低(<0.60),Ph/nC_(18)比值高(>1.30),伽马蜡烷含量高,伽马蜡烷指数介于0.90~1.36,属于典型咸水湖相原油,这与研究区古近纪的沉积特征一致。但依据不同原油中长链三环萜烷系列的分布与组成特征,可将他们分成两类:一类原油中C_(19-49)长链三环萜烷系列异常丰富,C_(19-30)TT/C_(27-35)H比值大于1.60,C_(23)TT/C_(30)H>1.40,并伴随有高甾藿比(>4.50)和高β-胡萝烷/nC_(37)比值(>3.20),表明藻类是其主要原始生烃母质;另一类原油中C_(19-30)长链三环萜烷系列含量中等,C_(19-30)TT/C_(27-35)H比值小于0.50,C_(23)TT/C_(30)H<0.55,其甾藿比相对较低(<2.0)、β-胡萝卜烷含量中等,β-胡萝烷/nC_(37)比值小于1.50,可见此类原油中藻类的贡献明显低于前一类原油。对比它们的甾、萜烷和金刚烷类化合物成熟度参数,发现这两组原油的成熟度相近,其对应的R_(o)值介于1.1%~1.3%,即它们形成于生油高峰之后、凝析油气形成以前这一演化阶段。【结论】影响研究区原油中长链三环萜烷系列相对丰度的主要因素是原始生烃母质,而非成熟度,因而它在研究区具有指示原油成因类型的作用,在后续油气勘探中应重点关注。

渤南洼陷沙四段膏泥岩中高丰度孕甾烷成因及其指示意义

渤南洼陷沙四段膏泥岩样品中检出了高丰度孕甾烷(相对于规则甾烷),孕甾烷/规则甾烷值为0.52~7.88,平均值为3.12。这些膏泥岩样品具有指示性较强的盐湖相生物标志化合物分布特征,如较低的姥鲛烷/植烷值(Pr/Ph=0.12~0.76)、高伽马蜡烷指数(GI=0.04~1.45)、高升藿烷指数(HHI=0.03~0.22)和较高的二苯并噻吩/菲值(DBT/P多大于1),均指示了高盐度水体、强还原性和富硫沉积环境,生源输入主要为嗜盐菌和藻类等低等水生生物。根据渤南洼陷沙四段原油中检出丰富的含硫甾烷,推测渤南洼陷高丰度孕甾烷可能与含硫甾烷形成过程中的不完全硫化作用有关。通过剖面上各生物标志化合物参数随埋深的纵向变化特征发现,孕甾烷与Pr/Ph、HHI和GI值等呈现良好的相关性,它们均指示还原、高盐度以及富硫贫铁的沉积环境。

Comparison of the capacity of biological desulfurization of Thiobacillus ferrooxidans from different sulfur-containing substrates with or without additional ferrous iron

Thiobacillus ferrooxidans,abbreviated as T.ferrooxidans is one of the important microorganisms in the field of biological desulfurization.Effects of ferrous iron and sulfur-containing substrates on biological desulfurization of T.ferrooxidans were studied.Results show that in the absence of Fe^(2+),T.ferrooxidans can utilize three kinds of sulfur-containing substrates of Na_(2)S_(2)O_(3),elemental S and Na_(2)SO_(3) for growth and metabolism.For utilization complexity,Na_(2)S_(2)O_(3) was easiest to use,next was elemental S,and Na_(2)SO_(3) was the worst for use.During the utilization of ferrous iron and sulfur-containing substrates by T.ferrooxidans,the iron oxidation system was first started.With the decrease of the Fe^(2+)concentration,the sulfur oxidation system was started,and then the two systems synergistically acted.The presence of three sulfur-containing substrates had different effects on Fe^(2+)oxidation,and elemental S did not inhibit the oxidation of Fe^(2+),while Na_(2)S_(2)O_(3) and Na_(2)SO_(3) had some inhibition on the oxidation of Fe^(2+),especially the inhibition of Na_(2)SO_(3) was significant,and complete oxidation of ferrous iron needed more time.The isolated T.ferrooxidans is applied to the removal of H2S gas,aiming to provide a new technological approach for biological removal of H2S.

Nickel(II)-Catalyzed Reductive Coupling of Xanthate Esters with Sulfur-Containing and Selenium-Containing Compounds:Synthesis of Unsymmetric Sulfides and Selenides

Unsymmetric sulfides and selenides have great applications in the pharmaceutical field.Herein,we describe the reductive coupling reaction of xanthate esters with sulfur-containing and selenium-containing compounds(thio(seleno)sulfonates and disulfides(selenides))under the nickel-catalyzed condition.It provides a mild and effective method for the synthesis of unsymmetric sulfides and selenides which has the advantages of mild reaction conditions,high yields and a wide range of substrates.

城市大气细颗粒物中烃类污染物的污染特征、来源及影响因素研究

正构烷烃、霍烷和甾烷是大气细颗粒物(PM_(2.5))中常见的烃类污染物。然而,这类污染物在城市不同区域的污染特征及其与人类活动之间的关联仍缺乏认识,环境因子对其大气浓度的影响还有待探明。本项目以大城市广州为研究区域,对PM_(2.5)中两类烃类污染物进行分析。结果发现,广州这两类烃类污染物的浓度(正构烷烃:1.75~126 ng/m^(3),霍烷和甾烷:0.077~3.35 ng/m^(3))整体低于我国其他城市;正构烷烃浓度在工业活动相对较为密集的城区较高;石化企业的生产活动对霍烷和甾烷具有潜在的排放贡献。正构烷烃特征指标显示,植物源是PM_(2.5)中该类污染物重要的来源;在市政和工业活动密集的采样点,人为源的影响更为显著。源解析模型也证实,植物源对城区正构烷烃的排放贡献达38.1%,高于生物质燃烧和机动车尾气等排放源。夏季,机动车尾气对霍烷和甾烷的排放贡献明显增加;该类污染物在其他季节主要源于煤燃烧。温度和风速是影响这两类烃类污染物大气浓度最重要的环境因子,与污染物浓度呈负相关;环境因子对正构烷烃浓度的影响与其同系物的碳数有关。

水松叶片含水热降解产物中饱和烃生物标志化合物组成特征及其指示意义

基于水松加水热模拟实验,对正构烷烃、类异戊二烯和甾烷类化合物等水松热解主要产物进行了研究。实验结果表明,随模拟实验温度升高,热解产物中,正构烷烃含量逐渐增加,主峰碳也由最初的n-C27逐步前移,Pr/n-C17和Ph/n-C18比值增大,规则甾烷分布由“V”形转变为反“L”形,达到340℃后各类化合物不稳定发生热裂解,多种参数发生改变。通过探讨生物标志化合物在有机质熟化过程中的演化规律,为陆相有机质生烃机理的研究提供基础认识。

UNUSUAL DISTRIBUTION OF TRITERPANE AND STERANE TERRESTRIAL BIOMARKERS IN YACHENG CONDENSATES FROM YING-QIONG BASINS, SOUTH CHINA SEA

The condensates from the Yacheng Gas Field, Ying-Qiong Basins, have unusual chemical characteristics, with distribution dominated by terpanes and steranes derived from higher-plants. Pr/Ph ratios (6-11) are very high. Drimane, cadinanes and homocadinanes exist in high concentration. Anomalously abundant 18α(H)-oleanane and remarkably abundant bicadinanes are present in Yacheng condensates, while 17α(H)-hopanes are in extremely low concentration. Taraxastane and significantly abundant 17α(H)-diahopanes occur in the condensates. In addition, a number of C 29 and C 30 unknown pentacyclic triterpanes were monitored in the condensates, some of which are abundant. The unknown compounds may be terrestrial biomarkers or their occurrence may suggest a sub-oxic (dyacrobic) clay-rich depositional environment. C 29 homologues are relatively predominant in regular and rearranged steranes. The concentration of diasteranes is markedly higher than that of regular steranes. The characteristics of Yacheng condensates are indicative of terrestrial source input. Based on condensate-condensate and condensate-rock correlations, combined with results of studies on sedimentary facies. Yacheng condensates may be sourced from Yacheng and Lingshui Formations in the Qiongdongnan Basin. The maturity of Yacheng condensate is relatively high, at late oil window stage (corresponding to 0.9%-1.3% R 0), based on sterane and terpane maturity parameters.

北部湾盆地沟鞭藻类分子化石的分布及成因

北部湾盆地流沙港组二段湖相烃源岩是盆地的主力烃源岩,其中检测到甲藻甾烷和三芳甲藻甾烷,以及丰富的4-甲基甾烷等重要分子化石。通过对北部湾盆地北部地区古近系流二段烃源岩的元素地球化学和有机地球化学特征等分析,研究了富有机质页岩的古氧化还原条件和古盐度,并进行甾类生物标志物对比,探讨了甲藻甾烷,三芳甲藻甾烷和C_(30)-4-甲基甾烷分布特征及其与沟鞭藻的成因关系。研究结果表明:流二段底部富有机质页岩中的C_(30)-4-甲基甾烷和三芳甲藻甾烷丰度呈负相关关系,表明弱还原的淡水—微咸水沉积条件可能不适宜甲藻甾烷和三芳甲藻甾烷的形成,而可以形成高丰度的C_(30)-4-甲基甾烷。油页岩中高丰度的C_(30)-4-甲基甾烷与其较高的成熟度有密切的关系。

甾烷类化合物分子印迹聚合物功能单体的筛选及MIPs制备

为了制备对甾烷类化合物具有特异性选择能力的分子印迹聚合物(MIPs),利用紫外光谱法对预聚合体系进行筛选,确定功能单体的种类、配比及其作用方式。将3种模板分子(胆固醇、β-谷固醇、去氧胆酸)分别与4种功能单体,即丙烯酸(AA)、甲基丙烯酸(MAA)、甲基丙烯酸甲酯(MMA)、丙烯酰胺(AM)的相互作用强度进行对比。研究结果发现,功能单体AA均可与3种模板分子发生较强的相互作用并形成稳定的预聚合体系,从而优选出AA为MIPs的功能单体。另外,通过不同比例AA紫外光谱吸光度变化和差示紫外光谱分析,显示3种模板分子与功能单体AA的最佳浓度比均为1∶4,且形成的稳定配合物构型分别为胆固醇-1AA、β-谷固醇-1AA及去氧胆酸-3AA。同时,以EDGMA为交联剂、AIBN为引发剂,采用沉淀聚合法成功合成了MIPs,傅立叶变换红外光谱(FTIR)分析结果显示MIPs制备良好。因此,此方法可用于对甾烷类化合物具有特异性选择能力的MIPs功能单体的筛选及其制备,并为深层—超深层烃源岩油源对比研究提供技术支持。