钛白粉生产过程的生命周期评价

按照生命周期评价（LCA）方法，对攀枝花地区钒钛磁铁矿的开采、选矿、运输以及硫酸法生产阶段进行了研究，定量地分析了整个生产过程中的资源、能源投入、环境排放及其环境影响，针对分析中发现的资源投入、能源消耗等关键环节和主要环境问题，联系工艺与设备进行了讨论，旨在为钛白粉行业的技术改进、清洁生产以及区域规划提供基本的数据支持。     

氮离子注入对1Cr18Ni9Ti耐蚀性能的影响

氮离子注入用于提高金属材料的耐磨性、耐疲劳性能,研究较多,工程上已有应用实例。用于耐水溶液腐蚀方面研究得较少,仅见对纯铁和碳钢耐蚀改性的理论研究。本文介绍用氮离子注入对1Cr18Ni9Ti不锈钢进行表面改性以提高在硝酸磷肥溶液中的耐蚀性能,通过表面成份及组织结构分析探讨耐蚀改性的机理。     

金属材料的小孔腐蚀

<正> 一、前言小孔腐蚀是钝性金属在含有活性离子的介质中一种常见的局部腐蚀。化工生产中常用的碳钢、不锈钢、铝、钛等材料在活性离子(Cl~-、Br~-、I~-、ClP_4~-、SCN~-等)的作用下,会发生小孔腐蚀,铜及铜合金,以及锆和钽等高耐蚀性金属,在一定条件下也会遭受这种腐蚀。生产中由于小孔腐蚀导致设备或管线穿孔的事例很多。例如,氮磷复肥生产中316L不锈钢换热器因磷矿石中带来的氯化物引起孔蚀而泄漏;化纤生产中纯铝冷却管被NaSCN溶液腐蚀穿孔;在沿海化工厂中,黄铜或白铜冷却器管子在海水作用下不到一年     

铈锆复合氧化物的研究及产业化进展

CeO2-ZrO2复合氧化物具有良好的储放氧性能(Oxygen Storage Capacity,OSc),可以有效地调节尾气空燃比、拓展催化剂的工作温度窗口,是汽车尾气三效催化剂(Three Way Catalysts,TWC)中的关键材料之一.随着环保要求的不断提高和相关排放法规的日益严格,对铈锆复合氧化物的热稳定性、低温还原性能和储放氧能力提出了更高的要求.简述了包括共沉淀法、溶胶-凝胶法、高能球磨法、模板法在内的铈锆复合氧化物常用合成方法,阐述了铈锆复合氧化物的基本改性机制,综述了常见的碱土元素以及过渡金属对铈锆复合氧化物的改性效果及原理,介绍了我国铈锆复合氧化物的市场需求、国内外主要铈锆生产厂家的生产技术及其主要产品性能、我国铈锆复合氧化物的产业化现状及进展.最后,从研究应用和产业化发展两个方面进行了展望.     

In situ DRIFTS study of NOx adsorption behavior on Ba/CeO2 catalysts

A series of Ba/CeO2 catalysts with different Ba loading amounts were prepared by incipient wetness impregnation. Their NOx adsorption behaviors under NO and NO＋O2 conditions were investigated by in situ DRIFTS. It was found that NOx was ad-sorbed and stored in the form of nitrites and nitrates on both Ba and Ce sites on the surface of the catalysts. The less thermally stable BaCO3 was suggested to be the main active phase for NOx trapping. Ceria served primarily as an oxygen supplier in the absence of O2, and the reaction from nitrites to nitrates on Ba sites was the key step in this case. In the presence of O2, however, gaseous O2 became the main oxygen source. The NOx adsorption capacity of the catalyst was dominated by the Ba content. Moreover, the stability of ni-trites and nitrates formed on Ce sites was found to be lower than those formed on Ba sites which existed in the form of the ionic bar-ium nitrate species.     

稀土催化材料的应用进展

众所周知，我国稀土矿以轻稀土组分为主，其中镧、铈等组分约占60％以上。随着我国稀土永磁材料、稀土发光材料、稀土抛光粉、稀土在冶金工业中等应用领域逐年扩大，国内市场对中重稀土的需求量也快速增加。造成了高丰度的铈、镧、镨等轻稀土的大量积     

还祖国一个美丽的蓝天简

雾霾引发全社会思考 2013年以来,我国的雾霾天气引起了全世界的关注。雾霾覆盖了我国国土面积的1/4以上,受影响人口达到约6亿人,涉及华北、黄淮、江汉、江南、华南、华南北部等多个地区。一些墩布在污染物监测中多次“爆表”,直冲严重污染的红线。     

Structure and oxygen storage capacity of Pr-doped Ce_（0.26）Zr_（0.74）O_2 mixed oxides

Binary Ce-Zr(CZ),Pr-Zr(PZ) and ternary Ce-Zr-Pr(CZP) mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction(XRD),Raman spectra,X-photon spectra(XPS) and CO temperature programmed reduction(TPR) were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity(OSC) was evaluated with CO serving as probe gas.The results showed that a pseudo cubic structure was formed for the Zr-rich ceria-zirconia mixed oxides with Pr doping.The insertion of Pr prevented the phase segregation of the mixed oxides during the hydrothermal ageing.The Pr doped samples showed better redox performances in comparison with CZ,and the sample doped with 5 wt.% Pr showed the most remarkably promoted dynamic oxygen storage capacity.This phenomenon was closely related to both the reducibility and oxygen mobility of the mixed oxides.The introduction of praseodymium into ceria-zirconia could accelerate the oxygen migration by increasing the amount of oxygen vacancies,although it was difficult for Pr3+ ions themselves to participate in the oxygen exchange process.     

新型多层太阳电池薄膜性能

Au薄膜作为新型多层太阳电池关键的组成部分,其表面染料吸附量对电池性能有很大的影响。采用亚硫酸盐电镀法制备纳米Au薄膜,利用扫描电镜研究了Au薄膜的表面形貌,利用紫外可见分光光度计研究了汞溴红在Au薄膜表面的吸附工艺和性能,并计算出Au薄膜表面的最大染料吸附量。采用亚硫酸盐电镀的Au薄膜制备出这种多层太阳电池,并测试了其光电转换效率。