水泥基材料对铬污染土壤的固化/稳定化研究

通过毒性浸出和无侧限抗压强度实验研究单掺硅酸盐水泥熟料、FeCl2以及复掺硅酸盐水泥熟料与FeCl2对铬污染土壤的固化/稳定化效果及作用机制。结果表明,熟料水化产物包裹和连接土壤颗粒,填充孔隙和离子渗出通道,而FeCl2在碱性条件下仍具有良好的还原性,两者共同作用,使土壤获得较高的强度,同时降低Cr(Ⅵ)的浸出浓度。硅酸盐水泥熟料复合FeCl2是一种良好的铬污染土壤专用固化/稳定化材料。     

沸石及膨润土对水泥-铬渣体系中Cr(Ⅵ)浸出的影响

本文研究了沸石及膨润土对水泥-铬渣体系中Cr(Ⅵ)浸出的影响。结果表明:沸石和膨润土对Cr(Ⅵ)的浸出有较好的效果,在pH=3,掺量为30%的条件下,28d龄期掺入沸石和膨润土的硬化体中Cr(Ⅵ)浸出浓度分别下降了82%及63%,沸石的效果优于膨润土。雨淋的自然养护条件会导致体系中Cr(Ⅵ)的浸出浓度减少近一倍。同时,硬化体抗压强度随着掺量的增加而下降,膨润土对强度的不利影响大于沸石。     

硫硅酸钙的合成及水化性能的研究

以分析纯物料制备硫硅酸钙(C_5S_2$)矿物,通过XRD、f-CaO分析不同煅烧温度对C_5S_2$矿物合成的影响,Rietveld精修计算C_5S_2$矿物的合成率,SEM观测其形貌。将合成的C_5S_2$矿物按不同比例掺入硫铝酸盐水泥中,通过测定抗压强度及水化试样结合水含量来研究C_5S_2$矿物对硫铝酸盐水泥力学性能及水化速率的影响。研究表明:C_5S_2$矿物的最佳煅烧温度为1 150℃,合成率可达到94.9%,C_5S_2$晶体形貌为圆棒状。当C_5S_2$掺量在7.5%～10%时,水泥强度明显提高;当C_5S_2$掺量为10%时,水泥28 d强度可达到73.3 MPa。掺入适量C_5S_2$可以提高硫铝酸盐水泥的水化速率,当C_5S_2$掺量为10%时,水泥28 d结合水量达到27.48%,水化速率最高。     

以煤矸石为硅铝质原料制备水泥熟料的试验研究

为探索以煤矸石为硅铝质原料制备水泥熟料的热工工艺和合理配方,选取不同配方配制8种水泥生料,在实验室进行不同温度下煅烧水泥熟料的试验研究。对熟料样品进行了f-CaO质量分数测定和矿物组成分析,并对水泥凝结时间、抗压强度、水化放热进行了测试,结果表明:以煤矸石为硅铝质原料制备水泥熟料时,石灰饱和系数KH=0.89~0.95、铝率IM=1.2~1.6、硅率SM=2.1~2.6的范围内配制的水泥生料易烧性较好,适宜的煅烧温度为1400~1450℃。制备的水泥72h水化放热量低于PⅡ42.5型硅酸盐水泥。当熟料理论率值KH=0.95,IM=1.55,SM=2.55时,制备的水泥净浆3d抗压强度为45.3 MPa,28d抗压强度为95.3 MPa。     

电学方法研究掺有窑灰水泥的水化特性

利用非接触式电阻率新方法,研究普通硅酸盐水泥及粉煤灰和粉磨时间分别为1h、3h和4h的窑灰混掺后胶凝材料的水化特性.试验结果表明,窑灰分别粉磨1h、3h和4h后,在同样掺量情况下,对水泥浆体早期电阻率随时间的变化有明显的影响.高碱度和高Cl-、高SO3含量将直接影响到窑灰作为混合材或直接回窑后水泥的早期水化特性.不同掺量的粉煤灰在一定程度上可以平衡窑灰水泥浆体系中的碱,同时窑灰中的碱也可激发粉煤灰的早期活性,在熟料掺量小于50%时仍可获得较高的早期强度.     

硫铝酸钙-贝利特水泥熟料的低温制备及其水化性能研究

以煤矸石、脱硫石膏、石灰为主要原料,采用水热合成-低温煅烧方法制备了硫铝酸钙-贝利特水泥熟料,通过X射线衍射(XRD)、扫描电镜(SEM)等分析了水热合成物、煅烧试样及水化产物的矿物相,利用等温量热仪测定了水泥早期水化放热随时间的变化,并测定了水泥的力学性能。结果表明:在120℃下水热合成前驱体后再经煅烧,可在1 050℃低温下制成硫铝酸钙-贝利特水泥熟料。与一步法相比,该低温水泥的早期水化放热速率较高。当水泥中的二水石膏掺量为13%(质量分数)时,水泥1d、28d的抗压强度分别为30.2 MPa和57.3 MPa,28d的水化产物主要为长纤维状的AFt。     

污泥对水泥熟料烧成和强度的影响

利用污水处理厂污泥替代硅质原料配制多组水泥生料,污泥掺量变化范围0-10%,生料KH(石灰饱和系数)变化范围为0.88~0.97,在1400℃下煅烧,测定各熟料的f-CaO和强度,并结合XRD,SEM/EDS等分析,研究污泥掺量及生料KH对水泥熟料烧成和强度性能的影响。另外还对掺10%污泥所烧制的熟料进行了重金属溶出试验。结果表明,在生料KH保持0.94而污泥掺量变化的情况,污泥掺量在2.5%左右时对改善生料的易烧性和熟料强度均有利,而污泥超过这个掺量后,生料易烧性和熟料强度随污泥掺量增加而明显降低;在污泥掺量保持2.5%而KH变化的情况下,KH小于0.91时,掺入污泥对生料易烧性和熟料强度不利,而KH大于0.94时,污泥掺入能改善生料易烧性,对熟料强度也略有提高;即使水泥生料中污泥掺量高达10%,所烧制的水泥其重金属滤出值远远小于标准的规定值,不会对环境产生危害。从水泥生料易烧性、熟料强度和重金属溶出试验看,只要生料配比合理和污泥掺量合适,污泥可以在水泥生产中得到无害化处置和资源化利用。     

生态水泥中SiO2掺量对焚烧飞灰中重金属固溶特性的影响

按不同SiO2掺量(质量分数)进行垃圾焚烧飞灰的水泥固化试验,研究了SiO2掺量对熟料试样的重金属分布、浸出毒性的影响。结果表明,SiO2掺量低于16%时,提高掺量有利于增加熟料中Cr、Ni、Cu、As固溶率;但SiO2掺量超过16%后,重金属固溶率与其成反比。Cd、Pb、Zn的挥发率随SiO2掺量增加而减少,掺加SiO2能明显抑制Zn的挥发,但基本不影响Hg的挥发。SiO2掺量增加后熟料结构进一步致密化,重金属浸出量减少。     

水泥熟料固化重金属Cu2+和Zn2+及水化浸出行为分析

危废处理是当前的热点问题,水泥窑协同处置作为一种有效的处理方式,逐步为社会所接受。多数的危废中包含Cu²⁺和Zn²⁺,文章研究了危废中重金属Cu²⁺和Zn²⁺在水泥熟料中的固化性能和在熟料中的分布,并探讨了重金属在水泥净浆中的浸出行为和环境安全性。通过熟料易烧性X射线衍射(XRD),矿物相分离萃取,浸出实验得出:Cu²⁺和Zn²⁺均改善了熟料易烧性;Cu²⁺促进了C₄AF的生成,同时也促进了C₃S晶粒的生长,并固溶在其中;Zn²⁺与熟料形成新的矿物相Ca₁₄Al₁₀Zn₆O₃₅。通过相对分布系数(D)和分配系数(K_f)说明Cu²⁺主要分布在硅酸盐相中,硅酸盐相固化Cu²⁺的能力强于中间相;Zn²⁺主要分布在中间相中,中间相固化Zn²⁺的能力强于硅酸盐相。掺量为2.0%的Cu²⁺和Zn²⁺在水泥净浆7 d龄期的浸出浓度最大,分别为1.724和0.387 mg·L^-1。水泥熟料固化Cu²⁺和Zn²⁺在水泥使用过程中不会对环境造成二次污染。     

阿利尼特水泥研究进展及其发展应用前景

阿利尼特水泥是一种节能水泥。介绍了阿利尼特矿物的组成、结构和固溶能力,总结了阿利尼特水泥的水化硬化性能、力学性能和节能特性,重点分析了氯掺加量和煅烧温度对阿利尼特水泥熟料烧成的影响,提出了利用固体废弃物制备阿利尼特水泥的资源化利用新思路,指出了阿利尼特水泥生产和使用过程中急需解决的技术难题。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.……     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.