N-正丁基异辛酰胺和磷酸三丁酯的萃铂性能对比研究

溶剂萃取技术已被广泛应用于回收和分离提纯铂族金属。磷酸三丁酯(TBP)萃取分离铂成功地应用于失效汽车催化剂富集精矿溶解液中铂的萃取分离。分别用N-正丁基异辛酰胺(BiOA)和磷酸三丁酯(TBP)作为萃取剂,研究了对铂废料电解液中铂的萃取性能。N-正丁基异辛酰胺(BiOA)的一级萃取率高达99.85%、萃取容量达20.1 g/L、用水作反萃剂的累计二级反萃率达99.5%;磷酸三丁酯(TBP)的一级萃取率达99.2%、萃取容量达16.5 g/L、用水作反萃剂的累计二级反萃率在50%左右。BiOA萃铂体系在以上3方面的性能优于TBP萃铂体系,但还需进一步做更多更深入的研究,探寻BiOA萃铂体系的工业化应用可能。     

用乳状液膜法分离浓缩L-苯丙氨酸

以煤油－Ｎ２０５－Ｐ２０４－ＨＣｌ组成的乳状液膜体系，在喷射提取柱内分别对Ｌ－苯丙氨酸及Ｌ－苯丙氨酸和Ｌ－天冬氨酸的混合溶液进行提取。实验结果表明，用１０００ｍＬ乳状液对初始浓度为２１．２５ｇ／Ｌ的单一Ｌ－苯丙氨酸水溶液提取３次后，外相浓度降到０．９５ｇ／Ｌ，内相最高浓度为１２６．１０ｇ／Ｌ；对Ｌ－苯丙氨酸浓度为８．６４ｇ／Ｌ的混合溶液提取两次后，外相Ｌ－苯丙氨酸浓度降至０．９０ｇ／Ｌ，内相Ｌ－苯     

N-正丁基异辛酰胺对铂的萃取性能研究

溶剂萃取技术已被广泛应用于回收和分离提纯铂族金属。随着新萃取剂和新萃取体系的研究开发,贵金属萃取技术研究不断取得新的进展。用N-正丁基异辛酰胺(BiOA)作为萃取剂,研究对铂废料电解液中铂的萃取性能。在合适的萃取条件下,即酸度为4 mol/L、萃取剂浓度为2 mol/L,相改善剂磷酸三丁酯(TBP)的加入量为3vol%,萃取率达99.5%以上;用水作反萃剂,反萃率达99.2%以上。铂反萃液,通过常规的水合肼还原的方法,即可获得99.95%纯度的海绵铂。该萃取体系高效、环保,具有工业化的应用价值。     

反胶团萃取分离纯化色氨酸

色氨酸是人体内的必需氨基酸之一。针对色氨酸的分离纯化,提出一种基于CTAB为表面活性剂的反胶团法分离纯化方法。结果表明,CTAB浓度为40mol／L;以正丁醇作为有机溶剂;异辛烷作为助表面活性剂,二者之比为1：1（V：V）;萃取PH为12;萃取离子选择氯化钾;萃取浓度为0．3mol／L;反萃PH为4;反萃离子为氯化钾;萃取浓度为2mol／L,萃取时间为15min;水浴振荡250r／min;反萃时间为20min;水浴振荡250r／min;萃取温度为室温;回收率最高可以达到60％左右。     

用反萃界面沉淀法制备二氧化钛超细粉体

用反萃界面沉淀法,以氨水为反萃剂,通过优化煅烧温度和反萃条件制备出超细TiO2光催化剂.结果表明,采用反萃沉淀法制备超细TiO2光催化剂,改变煅烧温度和水油相加入的方式、降低氨水的浓度、制备温度和陈化时间等因素均有显著的影响.用氨水反萃制备纳米TiO2其最佳煅烧温度为350℃,氨水的浓度和陈化温度存在最佳值.氨水浓度(体积比)为1:5,陈化温度为17.5℃有利于生成小颗粒;陈化时间较短和将水相加入油相有利于生成小颗粒.     

钴离子在P507—CCl4液膜体系中的活性迁移

研究了在Ｐ５０７－ＣＣｌ４大块液膜体系中，载体Ｐ５０７浓度、反萃液硫酸的浓度、料液ｐＨ、醋酸根浓度等因素对Ｃｏ２＋的活性迁移的影响．实验结果表明，载体浓度增加，Ｃｏ２＋的迁移通量增加．反萃液硫酸浓度增加，料液ｐＨ及醋酸根浓度适度增加均有利于Ｃｏ２＋的迁移．实验中观察到Ｃｏ２＋在膜迁移中的滞留现象，并在支撑液膜实验中测定了较大的Ｐ５０７浓度时Ｃｏ２＋的渗透系数Ｐ．     

三正辛胺—二甲苯支撑液膜萃取Cd（Ⅱ）的研究

研究了Ｃｄ（Ⅱ）在三正辛胺－二甲苯支撑液膜体系中的迁移规律．结果表明,载体三正辛胺浓度显著影响Ｃｄ（Ⅱ）的渗透系数Ｐ．料液中Ｈ＋浓度、Ｃｄ（Ⅱ）浓度和膜溶剂对Ｃｄ（Ⅱ）的迁移有影响．在此液膜体系中反萃剂醋酸铵比氢氧化钠好,温度升高能提高Ｃｄ（Ⅱ）的迁移速率．     

中空纤维支撑液膜去除水中氨氮的传质行为研究

以聚丙烯(PP)中空纤维膜为支撑体,二(2-乙基己基)磷酸(简称D2EHPA)为载体,煤油为膜溶剂,探讨D2EHPA-煤油-H2SO4中空纤维支撑液膜(SLM)体系对水中氨氮的传质行为.以去除率为指标,考察了料液初始氨氮浓度及pH值、载体浓度、反萃剂浓度对传质效果的影响;并通过对比实验分析了导致传质速率降低的主要原因.结果表明:在反萃剂H2SO4浓度为2 mol/L,料液相pH值在8～13范围内,提高料液pH值、增大膜相中载体浓度,均能提高氨氮的去除率.D2EHPA-煤油-H2SO4体系对氨氮的传质能力随氨氮浓度降低而下降.料液中氨氮浓度下降和pH值降低是导致氨氮传质速率降低的主要原因,调节料液pH值可调控和提高氨氮的去除与传质效果.     

砷的乳状液膜分离与分光光度测定研究

研究了表面活性剂，液体石蜡，内相反萃剂，油内比和料液中盐酸，ＫＩ浓度等条件对分离，富集砷的影响，确定了兰１１３Ａ－液体石蜡－煤油－ＮａＯＨ液膜体系最佳组成和其它最适实验条件。分离后的砷用ＤＤＴＣ－Ａｇ法测定，多种常见共存离子不影响砷的分离和测定；对实样品用标准加入法测定，回收率９７．６％，相对标准偏差为１５％。     

用反萃界面沉淀法制备氧化锌超细粉体

以草酸乙醇水溶液反萃Zn-P204-CCl4组成的有机相中的锌离子获得草酸锌前驱体,经450℃条件下煅烧得到的氧化锌粉体.结果表明,有机相中P204浓度的增加、无机相中草酸浓度的降低、乙醇浓度的增加和反应体系温度的降低有利于降低氧化锌粒径.在适宜条件(有机相: P204 35%(体积分数); 无机相: 草酸浓度0.3mol/L,乙醇的浓度80%(体积分数);反应温度为20℃)下,可以制备平均粒径约32nm氧化锌超细粉体,此氧化锌光催化降解亚甲基蓝的最佳投加量为0.4g/L.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...