用CCS—140型高频红外碳硫分析仪测定硅钢中微量碳和硫

硅钢中碳和硫的含量不仅非常低而且含量范围又非常的窄。因此,在冶炼硅钢时配备一台分析速度快,准确度高的碳硫分析仪是必不可少的。 目前,上海德凯仪器公司研制出国产CCS-140型高频红外碳硫分析仪。该机采用热释电固体红外检测器和相关信号处理技术,同时还使用了微机处理系统,具有较高的分析灵敏度和分析准确度,分析速度快等特点。半年多在生产上使用获得了比较满意的结果,满足了硅钢生产的需要。 1 仪器与试剂 CCS-140型高频红外碳硫分析仪(上海德凯仪器公司) 工作气体:氧气纯度≥99.5％     

口腔气体检测仪校准装置的研制

利用研制的三通道渗透管装置发生摩尔分数范围为0.1~1.0μmol/mol的硫化氢、甲基硫醇、二甲基硫醚混合气体,用于校准检测口腔气体检测仪。校准装置可以在固定输出总流量不变的情况下,快速改变发生硫化物的摩尔分数。对校准装置的温控系统和流量系统进行了测试,通过总硫分析仪对校准装置发生的低含量硫化物的量值进行了比较和验证。该校准装置发生的低含量硫化物量的相对扩展不确定度不大于6.8%(k=2)。     

小型高分辨电子轰击离子源反射式飞行时间质谱仪的研制

常用的气体分析质谱仪使用四极杆质谱作为分析器,分辨率一般低于300,无法解决同质量数离子带来的干扰问题.本实验自行研制了一种小型高分辨气体分析质谱仪,它采用电子轰击离子源反射式飞行时间质量分析器.仪器腔体总长45 cm,在m/z 28的位置,质量分辨率达到3000(Full width at half maximum,FWHM),实现了CO和N2的半峰谷分离;在m/z 69的位置,仪器分辨率达到5000(FWHM).在直接大气压进样条件下,可以检测到空气中136Xe(含量7.8 μ g/m3)和80Kr(含量2.8 μg/m3).使用ADC采集时,仪器的动态范围为1 06.该仪器将作为高端气体质谱仪,应用于过程监测在线分析、环境有机挥发物研究、热分析质谱及催化反应监测等领域.     

几种古老的气体发生装置

十八世纪末,硫化氢气体因被用作分析试剂出了名,随之而来的是需要有一种连续产生硫化氢气体的仪器装置,许多化学家为之努力工作,发明了不少仪器装置,成为现代气体发生器的先驱。格里芬（J.J.Griffin）曾经介绍过一种气体瓶（见图1）,它由两个圆球组成,下球内装硫化亚铁固体,从上球口加人足够量的酸就能与硫化亚铁发生反应产生硫化氢气体。     

将硫化氢转化为氢和硫的方法和装置

用于从进料气体获得氢产物和硫产物的方法和装置。进料气体包括硫化氢、氢产物包括元素氢硫产物包括元素硫。在该方法中，第一分离步骤分离进料气体以获得包括至少体积分数约90％硫化氢的第一纯化硫化氢级分。离解步骤离解存在于第一纯化硫化氢级分中的硫化氢，以将其转化为包括元素氢和硫的离解的第一纯化硫化氢级分。第二分离步骤分离离解的第一纯化硫化氢级分，以获得包括元素氢的富氢级分。也可以从离解的第一纯化硫化氢级分获得硫产物。最终，从富氢级分获得氢产物。     

测定甲醇合成气中微量硫化物的注意事项

根据微量硫分析仪测定人工煤气中微量硫化物的原理和仪器本身的特点，分析了用该法测定甲醇合成气中微量硫化物时，温度、气体配比等因素对测定结果的影响，指出了测定时应注意的事项。     

TL852系列碳硫分析仪的性能与特点

TL 852系列碳硫分析仪,系在TL 851系列碳硫分析仪的基础上,吸收国内外90年代仪器制造技术和碳硫分析技术,精心设计、精心制造的新一代分析仪器,技术先进,性能可靠,受到用户欢迎。 1 TL 852电弧燃烧炉 电弧炉已有25年的历史,它最大的特点是省电、省时,能对样品实现高速燃烧。但早期的电弧炉对样品的燃烧是不完全的,究其原因有二:一是电弧功率低,能量小,对样品的引燃效果差,尤其是特种样品,更是无能为力;二是采用铜锅燃烧样品。铜是热的良导体,样品燃烧过程中产生的热量(电弧炉热量的主要来源)绝大部分被铜锅传递吸收,燃烧温度达不到碳硫分析所需的高温,碳硫回收率低,且不稳定。 TL 852电弧燃烧炉,采用高频高能电弧,电弧功率达4kW。不仅适用于普通卷状样、屑样,对较难燃烧的粉末样和炉前甩片样等特种样品,均有很好的引燃效果,引燃率达100％。 TL 852电弧燃烧炉,采用陶土坩埚燃烧样品。陶土为保温材料,热传导率比铜低几个数量级,可充分利用样品燃烧过程中产生的热量,提高炉温和高温持续时间,有利于碳硫的充分完全氧化。     

钨丝电热蒸发-氩氢火焰原子荧光光谱分析法研究

以钨丝原子化器替换传统氢化物原子荧光分析仪石英炉原子化器及其氢化物发生气体进样系统,构建了一种新颖的集电热蒸发进样-氩氢火焰原子化为一体的原子荧光光谱分析系统;并用标准溶液研究了该系统的分析性能.在优化的仪器条件下,直接在钨丝表面进样,Pb、Ni和Au的检出限分别为:1.5、2.0和2.0μL.再结合电沉积预富集技术,...     

定碳定硫分析仪检定规程的探讨和修订建议

JJG 395–1997《定碳定硫分析仪检定规程》中的部分技术要求和检定项目已不能满足现代碳硫分析仪器检定/校准的要求。对规程的适用性、称量稳定性、示值误差、标准物质、重复性、分析时间等进行了探讨,并给出了修订建议。探讨了评定仪器检测空白的可能性,提出了依据碳硫测定基准国标方法的仪器检定/校准方法,以评定不同用途的测试仪器,并扩展了仪器检定/校准的范围。为计量部门修订规程提供参考,同时也为实验室合理评价,验收碳硫分析仪,及时掌握仪器的运行状况,保证分析数据的准确性、一致性和溯源性提供借鉴。     

利用正交试验法确定碳硫分析仪的分析工艺条件

在钢铁试样分析中 ,碳和硫几乎是必不可少的分析元素。本文利用正交试验法[1] ,根据它的“均衡分散性”和“综合可比性”的正交性原理 ,确定碳硫分析仪的分析工艺条件 ,利用该方法得出的分析工艺条件进行试样分析简便可行 ,其结果准确可靠。1　试验部分1.1　主要仪器与试剂ＣＳ 30 0型碳硫分析仪 (美国力可仪器公司 )Ｌ Ｃ .Ｓ坩埚 (湖南醴陵金利化工厂 )标样 :编号为 70 15 ,其中的碳含量ｗＣ0 .4 5 % ,硫含量ｗＳ0 .0 5 1%。纯钨粒 :助燃剂 ,粒度为 4 0目 ,其中ｗＣ<0 .0 0 0 8% ,ｗＳ<0 .0 0 0 5 %。氧气 :燃烧气 ,纯度大于 99.5 0 %氩…     

Acid volatile sulfide determination in sediments using elemental analyzer with thermal conductivity detector

A method for the determination of acid volatile sulfides (AVS) in sediments, using a common elemental analyzer with thermal conductivity detector, is proposed. The method uses a mixture of Sn and V(2)O(5) for pyrolysis and combustion to determine total sulfur (TS), and non volatile sulfur (NVS), after an acidic attack. AVS is calculated as the difference between TS and NVS. The method for TS is validated by analyzing a certified reference material. The recovery in the determination of acid volatile sulfide is determined by spiking a river sediment with ZnS. The method is accurate and gives a good reproducibility, recovering 97.7-99.6% of the sulfur in the 0-3% total sulfur content, with SD of approximately 0.015%.     

纳米分子筛的合成及硫化氢吸附性能

利用无模板水热法合成纳米尺寸的小孔SOD型和大孔X型分子筛, 并考察了其硫化氢脱除性能. 通过对比两种分子筛的硫化氢吸附性能, 证实分子筛对硫化氢的吸附主要集中于孔道内和可及的活性位. 考察了晶粒尺寸、 体积空速和吸附温度等因素对硫化氢吸附的影响, 发现纳米尺寸X型分子筛具有更大的硫容, 并且在低温和低空速下分子筛中的硫化氢分子易于脱除. 随后对纳米X型分子筛进行了金属离子交换改性, 发现Cu改性的分子筛硫容优于其它离子改性的吸附剂, 能达到20.6 mg/g. NaX-N和Cu-NaX-N再生后的硫容分别为新鲜分子筛的62.4%和78.5%.     

TG-MS与Py-GC相结合法研究惰性气氛下含硫模型化合物热解过程中硫的脱除及释放行为研究

采用热重-质谱法(TG-MS)和热解-气相色谱法(Py-MS)相结合的方法对模型化合物(十四硫醇、二丁基硫醚、苯硫醚、二甲基噻吩、苯并噻吩和二苯并噻吩等)在惰性气氛下硫的脱除及释放行为进行研究。惰性气氛下硫的脱除顺序为:十四硫醇>二丁基硫醚>二甲基噻吩>苯并噻吩>苯硫醚>二苯并噻吩,苯硫醚除外,该顺序与含硫官能团的热分解顺序一致。在热解过程中,所有模型化合物在质谱和气相色谱仪上均被检测到SO₂;除苯硫醚和二苯并噻吩外,其他模型化合物中均检测到了COS;而只在十四硫醇、二丁基硫醚和二甲基噻吩中检测到了H₂S。且热解气中SO₂含量要显著高于H₂S和COS。这是由于活性炭作载体时,惰性气氛下内部氢的含量显著小于内部氧的含量,所以大多数的含硫自由基易与内部氧结合以SO₂的形式逸出。对于苯硫醚、苯并噻吩和二苯并噻吩中没有检测到H₂S,是由于内部氢的不足,使得含硫自由基不能与内部氢结合,所以没有检测到H₂S逸出。     

Chemical and electrochemical processes in low-temperature superionic hydrogen sulfide sensors

Effect the morphology of the surface of the working electrode (PbS) exerts on the sensitivity of a low-temperature potentiometric hydrogen sulfide sensor is studied. The sensor, which is based on electrochemical cell Na _x WO₃/NASICON/PbS, may be used for fast selective detection of hydrogen sulfide in air in natural conditions. It is demonstrated that the sensors with PbS that are deposited out of solution have a faster response than the pressed-to ones. The dependence of EMF on the hydrogen sulfide concentration for the former is linear in semilogarithmic coordinates. Thus difference is explained by the microstructure of the lead sulfide layer. It is shown that the lead sulfide interaction with hydrogen sulfide involves a reversible partial reduction of sulfur and lead at the surface. The species that form in so doing contain sulfur atoms in lower oxidation degrees (poly-and oligo sulfides, sulfite). A mechanism of the sensor operation is proposed on the basis of data yielded by experiment and quantum-chemical simulation. The mechanism includes reversible transport of hydrogen from sulfur atoms to oxygen atoms.     

Fe-K/AC催化氧化脱硫剂制备及反应机理研究

采用正交实验法制备了负载铁、钾的活性炭(Fe-K/AC)热煤气催化氧化脱硫剂,考察了活性组分铁、钾含量、二价铁和三价铁比例、煅烧温度对催化氧化脱硫反应活性的影响。由正交实验极差分析可知,各因素影响程度依次为:钾含量>铁含量>煅烧温度> Fe²⁺/Fe³⁺,最优制备条件为,铁含量0.5%、钾含量5.0%、煅烧温度600 ℃、Fe²⁺/Fe³⁺比0.5。通过对脱硫剂的孔隙结构和表面形貌分析可知,活性炭表面负载的铁金属氧化物具有催化氧化硫化氢生成单质硫的活性,碱金属氧化物具有协同作用,可以改变表面酸碱性,促进硫化氢的催化转化,但过高的金属氧化物负载量会阻塞孔道,减小反应比表面积,从而降低脱硫剂的反应活性。     

Investigation of the mechanism of catalytic recyclization of furan to thiophene

Investigation of the formation of thiophene from furan and hydrogen sulfide at various catalysts showed that the activity of the catalysts increases with increase in the strength and concentration of Lewis acid centers. It was found by IR spectroscopy that if the degree of coverage of the aluminum oxide surface with hydrogen sulfide is higher than monolayer its dissociative chemisorption does not occur. Mechanism was postulated wich assume that the reaction takes place through stage with the formation of a surface intermediate, including coordination of the α-carbon atoms of the furan ring with the Lewis acid center and with the sulfur atom of molecular hydrogen sulfide.     

Control of Redox Events by Dye Encapsulation Applied to Light‐Driven Splitting of Hydrogen Sulfide

Solar production of hydrogen by consuming low‐value waste products is an attractive pathway that has both economic and environmental benefits. Inspired by the reactive pocket of enzymes, a synthetic platform to combine photocatalytic hydrogen evolution with sulfide oxidation in a one‐pot process via control over the location of the electron‐transfer steps is developed. The redox‐active coordination vessel Ni‐ TFT , which has an octahedral pocket, encapsulates an organic dye to pre‐organize for photocatalytic proton reduction via an oxidative quenching pathway using the nickel corners as catalysts, generating molecular hydrogen and the oxidized dye. The oxidized dye is displaced by a neutral dye and oxidizes sulfide once outside the pocket to give element sulfur. The overall reaction constitutes hydrogen sulfide splitting, forming molecular hydrogen and elemental sulfur, which is analogous to the water‐splitting reaction.     

Sulfur modification of polyethylene surfaces. I. Insertion of sulfur into polyethylene surfaces

Atomic sulfur generated respectively by the pyrolysis of carbonyl sulfide and by the photolysis of carbonyl sulfide, carbon disulfide, and sulfur vapors has been shown to modify irreversibly the surface of polyethylene as shown by wettability measurements. The nature of the modification is not completely apparent from this portion of the study, however, insertion of the atomic sulfur into a carbon—hydrogen bond to form a surface thiol group appears likely. The modified surfaces thus formed are shown to undergo several classical organic reactions, as determined by wettability measurements.     

Mechanochemical reactions of elementary sulfur and iron sulfides with hydrogen,oxygen, and water

Mechanochemical reactions of elementary sulfur and iron sulfides with hydrogen, oxygen, and water were studied. Three reactions were discovered: (1) between elementary sulfur and dihydrogen, (2) between pyrite and dihydrogen, and (3) between elementary sulfur and water; these reactions are accompanied by hydrogen sulfide evolution. Mechanochemical synthesis of iron sulfide from the constituent elements in water involves hydrogen sulfide, which is generated by the reaction of elementary sulfur with water. We show that elementary sulfur is generated during pyrite oxidation by dioxygen during or after dispersion. In an oxygen-free medium, pyrite is more reactive to water than iron sulfide. Pyrite reacts with dihydrogen and water in an oxygen-free medium directly, avoiding the dissociation stage.