回程式钠离子交换器技术改造

本文详细分析了贵溪冶炼厂动力车间4#、5#钠离子交换器改造前存在的问题,提出了改造方案,介绍了改造后的使用效果,并对改造前后的运行数据、产生的经济效益和社会效益作了对比。     

Two-stage fast flotation of coal tailings using reflux flotation

Low pulp density and low grade slurries in the coal and minerals industries are discharged as waste to tailings dams, incurring significant losses of valuable particles. This paper investigates the rapid processing and cleaning of hydrocyclone overflow coal slurry using two laboratory scale Reflux Flotation Cells in series as a means to economically beneficiate low quality tailings streams. The Reflux Flotation Cell incorporates a novel arrangement of inclined channels to enhance bubble-liquid segregation, enabling extremely high gas rates and liquid rates per unit of vessel area. Hence, in the first stage, fast flotation is employed to rapidly recover fine coal particles using a feed flux of 11.4 ± 0.5 cm/s, up to an order of magnitude increase in the throughput rate over conventional flotation systems. First stage product was then sent to a second stage for counter-current washing using fluidisation wash water to produce a fully deslimed product, having ash percent in agreement with the minimum ash attainable using flotation as determined through tree flotation analysis. The results demonstrate the potential for two-stage Reflux Flotation to deliver high throughput at a high separation efficiency from low quality slurry, with a fivefold reduction in the required vessel footprint, thus overcoming the principal economic deterrent of having to install banks of large-scale flotation cells.     

Maximizing bubble segregation at high liquid fluxes

This study is concerned with a common class of problem involving two phase separation of a dispersed gas flow from a continuous liquid flow under extreme processing conditions. Relatively fine spherical bubbles of order 500 μm were generated in the presence of a surfactant under a high shear rate within a rectangular, multi-channeled, cuboidal downcomer. Liquid fluxes, as high as 176 cm/s through each channel of the downcomer, sheared bubbles from a sintered surface mounted flush to the channel wall before disengaging the downcomer flow into a vertical vessel. Both high feed fluxes, up to 15 cm/s, and high gas fluxes, up to 5.5 cm/s, ensured a high gas holdup beneath the downcomer and the hindered rising of the bubbles. Enhanced bubble–liquid segregation was achieved using an arrangement of parallel inclined channels incorporated below the main vertical chamber. This novel device, referred to as the Reflux Flotation Cell, prevented the entrainment of bubbles to the underflow, and significantly reduced the liquid flux to overflow, even in the absence of a conventional froth zone. Extreme upward bubble surface fluxes of up to 600 s⁻¹ were achieved, while counter-current downward liquid fluxes reached 14.4 cm/s, arguably four times the bubble terminal rise velocity. Hence successful phase separation was achieved while operating well beyond the so-called flooding condition arising from extreme levels of gas and feed fluxes. This hydrodynamic arrangement should find application in increasing surfactant extraction rates in foam fractionation and ion flotation, gas absorption, and even particulate flotation.     

Entwicklung einer leistungsstarken Mikrorektifikationsapparatur für analytische und präparative Anwendungen

In this contribution it is reported about the realization of efficient micro rectification equipment (MRA), which can be operated intermittently or continuously and be used both for analytical as well as for preparative separations of mixtures of liquid substances. Different binary systems were separated. A theoretical separation stage number of 12 was obtained together with a height equivalent to one theoretical plate of 1.08 cm. Compared to the state of microtechnology this can be regarded as an excellent progress.     

变频调速技术在靖安油田注水系统中的应用

本文针对靖安油田注水站场大部分时间处于变工况运行状态、普遍存在着高压回流的现象,结合往复式柱塞泵的工作原理,安装了变频调速装置,灵活应用闭环控制技术,通过改变注水泵电机转速来调节注水泵排量,减少了高压回流量,有效的降低了注水系统电能损耗,收到了良好的节电效果。     

水解酸化-活性污泥法处理卤代杂环类农药中间体废水的研究

采用水解酸化-活性污泥法工艺处理卤代杂环类农药中间体废水,研究了混凝预处理、活性污泥的驯化和培养以及污泥回流比等关键因素对农药中间体废水的脱色、COD去除率的影响。确定了生化处理的最佳条件。运行结果表明：当混凝剂的加入量为1‰、按10%速率提升进水负荷、水解酸化池的污泥回流比控制在40%～50%、深沉曝气池的污泥回流比控制在30%～40%时,系统出水水质可稳定达到金山第二工业区接管标准。     

三出口萃取工艺动态过程研究

本文根据总萃取比恒定的三出口萃取工艺(A/B/C)中各组份的动态物料平衡,采用 FORTRAN 语言编写了串级萃取动态模拟计算程序,并进行了正常启动和回流启动两种动态过程的实例计算。结果表明,各组份在级体内总量及各出口产品纯度等均随串级排数增多而逐渐趋近于静态模拟计算结果。采用回流方法启动时,可显著缩短达到稳态所需的时间,大大减少启动过程中的非合格产品。本文还根据多个萃取体系的动态模拟结果,分别对萃取段或洗涤段开设第三出口的工艺介绍了回流启动方法。     

酯交换法生产碳酸二甲酯工艺节能研究

以甲醇钠为催化剂,碳酸丙烯酯和甲醇为原料酯交换生产碳酸二甲酯.在传统工艺基础上对浮阀塔塔盘进行了改造,在新型反应精馏塔上进行了中试并考察了塔盘液位高度、回流比等因素对塔顶产品纯度的影响.结果表明,随着回流比增大,塔顶碳酸二甲酯含量开始增加并逐渐趋向稳定;随着塔盘液位高度增加,塔顶碳酸二甲酯含量增加并逐渐稳定;塔顶丙二醇...     

Preparation of Nano-structured LiFe_xMn_(1-x)PO_4(x=0,0.2,0.4) by Reflux Method and Research on the Influences of Fe(Ⅱ) Substitution

Nano structured LiFexMn1-xPO4(x=0,0.2,0.4) materials were successfully prepared by one-step reflux method in a water/PEG400 mixed solvent, and were coated by carbon using glucose as the precursor. The materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The electrochemical properties of the materials were investigated by galvanostatic cycling, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that the materials consisted of nanorods with a diameter of 50 nm and a length of 500 nm. Galvanostatic cycling showed that the capacity of LiMnPO 4 could be largely increased by Fe2+ substitution. At a current rate of C/20, the capacity of the three samples (x=0,0.2,0.4) were 47, 107 and 150 mA·h·g-1 , respectively. CV result showed that the Fe2+ substitution could decrease the polarization during charging/discharging, accelerating the electrochemical process. EIS result showed that the Fe2+ substitution could decrease the charge transfer resistance between the electrode and electrolyte,     

浅析制氩系统二次氮塞发生的原因及处理

在处理制氩系统轻微氮塞过程中,因为主塔回流比过大,发生了更严重的二次氮塞。简介制氩系统流程,详细介绍氮塞故障的发生经过和原因分析过程,并阐述氮塞的消除方法。