含镍废液制备硫酸镍并深度除Fe、Cu、Zn

本文以镀镍行业产生的含Fe、Cu、Zn等杂质的硫酸镍废液为原料,通过采用氧化、化学沉淀、P204多级萃取等低成本的方法,实现了Fe、Cu、Zn等主要杂质的深度去除,制备出符合HG/T 2824-2009中Ⅰ类一等品的硫酸镍产品。试验重点考察了双氧水用量用量对除铁的影响,以及中和pH值、萃取pH值、萃取相比等技术参数对Fe、Cu、Zn、Ni除杂率的影响,并按照最佳条件处理了一批10 L废液得到2300 g硫酸镍产品,一次结晶率达60%。试验结果表明:用双氧水氧化后石灰中和至pH值5.0,Fe离子沉淀完全;在中和终点pH值4.5~5.7范围内,Fe、Cu、Ni的沉淀率随pH值的增大而增大,Zn的变化不大;pH值达5.7,Cu的沉淀率达98.4%;P204对金属离子的萃取顺序为:Fe3+Zn~(2+)Cu~(2+)Fe~(2+)Ni~(2+);P204可有效萃取分离Fe、Cu、Zn等杂质;经萃取分离后硫酸镍溶液中Fe、Cu、Zn的含量全部达到10-3g/L以下。     

Protonation of g-C3N4 and its temperature-sensing properties

Journal of Materials Science: Materials in Electronics - Graphitic carbon nitride (g-C3N4) was obtained through heat treatment of melamine and the g-C3N4 flakers were then protonated with sulfuric...     

ZnO Nanorods on a LaAlO3–SrTiO3 Interface: Hybrid 1D–2D Diodes with Engineered Electronic Properties

Integrating nanomaterials with different dimensionalities and properties is a versatile approach toward realizing new functionalities in advanced devices. Here, a novel diode‐type heterostructure is reported consisting of 1D semiconducting ZnO nanorods and 2D metallic LaAlO₃–SrTiO₃ interface. Tunable insulator‐to‐metal transitions, absent in the individual components, are observed as a result of the competing temperature‐dependent conduction mechanisms. Detailed transport analysis reveals direct tunneling at low bias, Fowler–Nordheim tunneling at high forward bias, and Zener breakdown at high reverse bias. Our results highlight the rich electronic properties of such artificial diodes with hybrid dimensionalities, and the design principle may be generalized to other nanomaterials.     

低品位微细粒金矿浮选精矿的处理工艺研究

针对低品位微细粒金矿中金的赋存特点,对其浮选精矿进行高压氧化-氰化浸出工艺处理。重点考察了高压氧化预处理过程中的温度、液固比和氧化时间对预处理效果的影响。预处理渣再磨后氰化浸出,金的浸出率(对浮选精矿)为94.30%,渣率为10.88%。     

玉龙喀什枢纽超高面板堆石坝的渗控方案及渗流分析

玉龙喀什水利枢纽混凝土面板堆石坝高度为230.5 m,为超高型的面板堆石坝,高度接近目前世界最高的同类坝型。本文依据高面板堆石坝渗流控制设计原则,对坝体进行了分区设计,提出了坝体混合料和全爆破料两种分区方案。使用三维有限元法,全面分析了坝体坝基的渗流场状况。结果表明:在正常运行条件下,上游水头由面板、趾板、高趾墩、坝基帷幕承担,渗控系统发挥了良好作用,面板及各填筑分区水力梯度均小于破坏水力梯度;全爆破料方案的坝体填筑料的最大水力梯度小于混合坝料方案,但是面板的防渗负荷相对较大;在面板发生整体渗漏的极端情况下,坝内浸润线和下游溢出高程升高的程度有限,但是极可能发生渗透破坏;坝基灌浆帷幕减少两岸渗漏的作用明显,河床和两坝肩渗漏量很小,绕坝渗流并不明显,受到右岸单薄山梁影响,右岸渗漏量略大于左岸。本文成果可供相似工程借鉴。     

Enhancement of the electrocaloric effect over a wide temperature range in PLZT ceramics by doping with Gd3+ and Sn4+ ions

The electrocaloric effect (ECE) in gadolinium and tin ions doped lead lanthanum zirconate titanate ceramics was investigated. Five samples with different compositions and hence different relaxor behaviors and polarization properties were prepared via a conventional solid-state reaction process. The ECE was measured directly by a high resolution thermometer from 293 K to 423 K. The results show that the ECE is mainly determined by the number of polarization states and polar-correlation strength. Furthermore, the results reveal that the temperature variation of ECE around Curie temperature is associated with the generation rate, activation energy, size and freezing temperature of polar nanoregions. As a result, Sn doped PLZT composition exhibits the best ECE, i.e., a peak ΔT > 2 K obtained at 5 MV/m, and ΔT > 1.78 K achieved in the whole temperature range measured at the same field, which are very attractive for high performance ECE devices.     

Effects of surfactant additives during ball milling on the microstructural,electrical, and piezoelectric properties of 0.4Ba(Zr0.2Ti0.8)O3-0.6(Ba0.7Ca0.3)TiO3 ceramics

Journal of Materials Science: Materials in Electronics - In this work, calcium barium zirconate titanate piezoelectric ceramics 0.4Ba(Zr0.2Ti0.8)O3- 0.6(Ba0.7Ca0.3)TiO3((1?x)BZT-xBCT,...     

Effect of various polymer additives on the rheology and thixotropy of organic vehicles

Journal of Materials Science: Materials in Electronics - In this study, the contents of ethyl cellulose (EC) as thickener in organic vehicle, which also acts as a binder, was examined using various...