Preparation of pure SnO_2 powders from tin slag of printed circuit boards waste

The recycling method and principle of SnO2 from the tin slag of printed circuit boards(PCB) waste were investigated. In this study, pure SnO2 powders were obtained through a multi-step process including ball-milling, roasting, dissolving, precipitating, and pickling. The total recovery rate of tin can be up to 91 %. The SnO2 powders obtained is the single phase, and the content of SnO2 is up to 99.9 %. However, the SnO2 particles are easier to agglomerate during the precipitation process. The agglomerate SnO2 particles are about 7.778 lm in mean particle size(D50). This preparation method presents a viable alternative for the tin slag recycling. The tin is not only recycled, but also reused directly to prepare pure SnO2 powders.     

Structure and electrical properties of (1-x)BaTiO_3+(x)La_(2/3)-Sr_(1/3)MnO_3 composites

Liquid-phase sintering method was used to prepare BaTiO 3 powders and the structure and electrical properties of (1-x)BaTiO 3 +(x)La 2/3 Sr 1/3 MnO 3 (LSMO) composites were investigated. The results of X-ray diffraction showed that the prepared BaTiO 3 powders were pure and fine, indicating that sintering temperature was effectively lowered when the NaCl sintering aid was added. X-ray diffraction patterns of (1-x)BaTiO 3 +(x)La 2/3 Sr 1/3 MnO 3 (LSMO) composites showed that LSMO and BaTiO 3 phases were coex...     

用MOD法制备BaPbO_3导电缓冲层

BaPbO3晶体为钙钛矿结构,与YBCO晶格具有一定的匹配性,属于半共格界面。在高温下化学性质稳定,不与YBCO反应,并且具有良好的导电性,因此很可能成为YBCO超导涂层的导电隔离层。实验采用乙酸钡和乙酸铅为原料,以丙酸为溶剂,制得了稳定均匀的涂层前驱液。经过旋转涂覆和适当的热处理工艺,在LaAlO3(100)单晶基底上生长了BaPbO3薄膜。经XRD分析其物相组成是单相的具有少许织构的BaPbO3;通过SEM观察其表面均匀致密,厚度约800nm;用四引线法测得薄膜室温电阻率为1×10-3Ω·cm。     

利用废玻璃和粉煤灰制备钙铝硅微晶玻璃及其性能

采用粉体直接烧结-晶化法,以废玻璃和粉煤灰为主要原料,制备了CaO-Al2O3-SiO2(CAS)微晶玻璃。利用差热-热重分析仪、X射线粉末衍射仪、扫描电子显微镜等分析手段,确定出微晶玻璃热处理工艺制度,并对微晶玻璃的晶相结构和显微组织进行了分析。结果表明:经过820℃烧结1 h,1100℃晶化热处理2 h获得的CAS微晶玻璃体积密度最大,吸水率最低;CAS微晶玻璃为单相硅灰石结构;抗弯强度最大值达81.5 MPa。     

氧化铝增韧陶瓷的高效ELID精密磨削实验研究

氧化物增韧陶瓷是一种高技术陶瓷材料,具有高强度、高韧性以及良好的耐磨、耐腐蚀性能。在一般的加工过程中,采用普通树脂砂轮对硬度较高的氧化铝增韧陶瓷材料进行磨削时,磨料的消耗比较快,磨削比较低,仅为8,10左右。通过ELID磨削对氧化铝陶瓷进行高效磨削实验,从砂轮速度、进给速度、砂轮粒度和砂轮电解活化钝化趋势等因素中,找到合适的加工工艺参数,使效率和精度达到最优。实验表明,砂轮速度和进给速度对磨削比影响较大;砂轮粒度和砂轮电解活化钝化趋势对表面质量影响较多。使用优化后的ELID磨削工艺使氧化铝陶瓷材料的加工效率提高了50％。磨削比增大到60～100。     

太阳能晶体硅切割废料中高纯硅的提取(英文)

研究从太阳能晶体硅切割废料中制取高纯硅。分析切割废料的组成、粒度分布等,利用物理沉降法对废料中的硅粉进行富集,然后经酸洗除杂。研究酸洗工艺参数如酸洗时间、温度、固液比等对提纯效率的影响,并优化工艺参数。最后将酸洗除杂的硅富集料进行真空高温熔炼获得含99.96%Si、1.1×10-6B及4.0×10-6P(质量分数)的高纯硅。结果表明:从晶体硅切割废料中回收太阳能多晶硅是未来的一个重要发展方向。     

Preparation of Cu-Ni Film Resistors with Low Resistivity and Low TCR

Thin film resistors with low TCR and low electric resistivity were prepared from phosphorus free Cu-Ni alloy obtained by electroless and electrolytic deposition with heat treatment at low temperature.     

Preparation and Electrical Resistance Characteristics of Electroless Copper-Nickel Alloy Deposits

Studies have been made of an electroless copper-nickel-phosphorus alloy from a citrate complex bath using hypophosphite as reducing agent and electroless copper-nickel binary alloy from a triethanolamine complex bath using formaldehyde as reducing agent. With an increase in copper content of alloy, the specific resistance of deposit decreased. The TCR of copper-nickel-phosphorus alloy increased remarkably because of the crystallization of Ni₃P after heat treatment. But the increase in TCR of copper-nickel binary alloy was moderate and not so striking as for the phosphorus containing alloy.     

Ir(ppy)_3分子的磷光发射温度依赖和磁场增强效应

应用磁光光谱技术,测量并研究了溶解在四氢呋喃(tetrahydrofuran,THF)中Ir(ppy)_3分子的磷光发射特性随温度和磁场的变化规律。发现在2.2 K时可见光波段Ir(ppy)_3有两个磷光发射峰,分别位于547.70和515.18 nm。这是由系统的金属到配位体电荷转移态(~3MLCT)中两个激发态到基态的光跃迁引起。改变温度可以改变三重态中亚能级I、Ⅱ和Ⅲ上的电子分布,使得磷光发射峰的强度在10 K时发生反转,并且光谱发射强度在20~300 K间随温度增加而减弱。在强磁场作用下,Ir(ppy)_3在2.2 K温度下的磷光发射强度随磁场强度增大而增强。外加磁场能改变~3MLCT态的三个亚能级上的电子跃迁几率,从而能增加磷光发射强度。     

余热锅炉流场温度场数值计算

用ｋ－ε方程模拟了余热锅炉内流场和温度场分布。几何拓扑结构用多块结构以减少计算机内存的浪费,用贴体坐标系统来描述复杂的几何边界,网格系统用交多格。使用才阶中心差分法离工用扩展项和源项,对于控制方程的对流项的离散采用混合差分（ＨＤＳ）格式。求解方程使用ＳＩＭＰＬＥ算法。给出了余热锅炉内流场和温度场的分布,为研究余热锅炉炉内流动和传热、传质提供了理论依据,对余热锅炉的设计、节能改造提供了详细的数据和有     

Influence of sintering schedule on the electrical properties of Mn（NO3）2-doped Ba0.92Ca0.08TiO3 PTCR ceramics

The relationship of electrical properties of Mn-doped Ba0.92Ca0.08TiO3 PTCR (positive temperature coefficient resistance) ceramics with two sintering schedules was discussed. Using TEM (transmission electron microscope) combined with EDS (energy dispersive X-ray spectrometer), the Mn ions distributed at grain boundaries were analyzed. The results show that the PTCR effect of Mn-doped PTCR ceramics is more dependent on the sintering schedule than those of Mn free. The phenomenon may be caused by the valence states variance of Mn ions segregated at the grain boundaries.     

Pr,Mn改性BaTiO_3陶瓷的制备及其PTC特性

采用溶胶凝胶法制备了Pr,Mn掺杂的BaTiO3陶瓷,并对其进行了Pr,Mn气相扩渗。研究结果表明,Mn掺杂能提高BaTiO3陶瓷的室温电阻率至1015Ω·m,但再经Pr扩渗后降至107Ω·m,经Pr-Mn共渗后降至2.01Ω·m。Pr掺杂能降低BaTiO3陶瓷的室温电阻率至105Ω·m,再经Mn扩渗后,室温电阻率变化不大,但经Pr-Mn共渗后室温电阻率显著降低,达到2.04Ω·m。Pr气相扩渗能显著降低电阻率,而Mn的加入有利于改善PTC特性。经Pr扩渗的Mn掺杂BaTiO3陶瓷在350℃后有明显的NTC效应,升阻比高达106;经Mn扩渗的Pr掺杂BaTiO3陶瓷在370℃附近出现突降点,电阻率降至0.1Ω·m,升阻比约为105。XRD分析表明,Pr,Mn掺杂或扩渗都没有改变BaTiO3陶瓷的物相结构。XPS分析表明,在气相扩渗过程中,C和Pr元素都进入了陶瓷体,并主要分布于晶界或者陶瓷的气孔中,导致了改性BaTiO3陶瓷电阻率的明显下降和NTC效应的产生。气相扩渗对掺杂后的陶瓷有减小结合能的活化作用,而对纯BaTiO3陶瓷有增强稳定性的作用。     

Separation of cadmium and nickel from waste Ni—Cd batteries

To separate the cadmium and nickel resources in waste Ni-Cd batteries,a self-designed vacuum distillation recycling system was studied under laboratory conditions.The effects of system temperature,operating pressure,and time on the separation of Ni and Cd were studied respectively.The mechanism of vacuum thermal recycling was also discussed.Results show that vacuum distillation is a very effective separation method for waste Ni-Cd batteries.At a Constant pressure,the increase of temperature can improve the separating efficiency of Cd.When the temperature is 1173K,Cadmium can evaporate completely from the samples during 3h at 10Pa,The reduction of pressure in a certain range is effective to the separating of Cd from Ni-Cd batteries by vacuum distillation.     

Preparation and performance of rare earth Zr catalyst for reforming waste plastics cracking product

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｓａｓｏｌｕｔｉｏｎｆｏｒ“ｗｈｉｔｅｐｏｌｌｕｔｉｏｎ” ,ｐｒｏｄｕｃｔｉｏｎｏｆｆｕｅｌｏｉｌｂｙｃｒａｃｋｉｎｇｗａｓｔｅｐｌａｓｔｉｃｈａｓｂｅｅｎｐａｉｄｍｕｃｈｍｏｒｅａｔｔｅｎｔｉｏｎ .Ａｌｏｔｏｆｓｔｕｄｉｅｓｏｎｗａｓｔｅｐｌａｓｔｉｃｃｒａｃｋｉｎｇｐｒｏｃｅｓｓａｎｄｆａｃｉｌｉｔｙｈａｖｅｂｅｅｎｃｏｎｄｕｃｔｅｄ ,ｂｕｔｎｏｔｓｏｍｕｃｈｏｎｔｈｅｒｅｌａｔｅｄｃａｔａｌｙｓｔ.Ｔｈｅｃａｔａｌｙｓｔｓｕｓｅｄｉｎｔｈｅｗａｓｔｅｐｌａｓｔｉ…     

ZnO-B_2O_3对CaCu_3Ti_4O_(12)陶瓷结构和介电性能的影响

采用传统固相反应法,将ZnO-B2O3(ZB)与1 100℃预烧的CaCu3Ti4O12(CCTO)粉末混合烧结成陶瓷。探讨ZB对CCTO陶瓷显微结构和介电性能的影响,并进一步分析CCTO陶瓷的巨介电机理。结果表明:当添加少量ZB(w≤2%,质量分数)时,形成体心立方BCC类钙钛矿结构的CCTO单相;当w>2%时,生成Zn2TiO4杂相;当ZB的添加量为0.5%和10%时,CCTO陶瓷的介电常数明显增大,介电损耗也较高;而当ZB的添加量为1.0%~5.0%时,介电常数的变化很小,同时具有较低的损耗和良好的温度稳定性。其中,w=2%时CCTO基陶瓷具有优异的介电性能(100 kHz),即相对介电常数εr=336,介电损耗tanδ=0.018,介电常数温度系数τε=-1.5×10-5℃-1。ZB掺杂CCTO基陶瓷的阻抗谱表明:CCTO陶瓷由半导体化晶界和相对绝缘的晶粒构成,因此,其具有巨介电常数。     

Effect of temperature on copper corrosion in high-level nuclear waste environment

The effect of temperature on the corrosion behavior of copper in simulated high-level nuclear waste environment was systematically studied. Electrochemical methods, including electrochemical impendence spectra, Mott–Schottky technology, cyclic polarization, and potentiostatic polarization, were employed to characterize the corrosion behavior of copper at different temperatures. Stereoscopic microscopy and scanning electron microscopy were used to examine the surface morphology, and X-ray photoelectron spectroscopy analysis was used to identify the composition of the passive film. The experimental results show that corrosion resistance of the passive film does not blindly decrease with the increase of temperature but increases at 60 °C owing to a compact outer layer; there is a potential for pitting corrosion, which decreases as the temperature increases. The main product of copper in an anaerobic aqueous sulfide solution is Cu₂S but the content of CuS increases at higher temperatures. The whole passivation range shows p-type semiconductor characteristics and the magnitude of the acceptor density is 10²³ cm^?3, which increases with increasing temperature.     

Corrosion of 15Mo3 carbon steel superheater tubes in waste incineration plants: A comparison between a field-returned tube and laboratory tests

In this study, a field-returned superheater tube of carbon steel 16Mo3 (1.5415) was analyzed in detail. In addition to cross-section analysis, different scales were investigated layer by layer using microscopic, diffraction, and spectroscopic techniques. The corrosion products can be divided into three layers: The layer adjacent to the metallic tube surface was an iron- and chlorine-rich scale, followed by an FeS layer present at the gas flow side, and the outermost layer was an iron oxide scale consisting of Fe₃O₄ and α-Fe₂O₃. The different mechanisms responsible for the structure of such scale formation and the different corrosion products formed at the tube are discussed. Furthermore, the root cause for the disability to form a protective scale under such conditions was identified by comparison with results from laboratory tests.