铁、钴、镍及其合金在氨-碳酸铵溶液中阳极溶解机理的探讨

<正> 一、前言氧化镍矿经还原焙烧后,焙砂中含有铁、钴及镍的金属相。因此本研究以铁、钴、镍及其合金为对象,探索它们在氨-碳酸铵溶液中的阳极溶解过程。还原焙砂的浸出过程,实际上是一个电化学过程。它由两类电极反应组成:一是金属的阳极溶解反应;一是氧的阴极还原反     

从溶剂萃取反向胶团合成优质ZrO_2超细粉SCIEI

提出了结合化工单元操作－溶剂萃取，实现金属氧化物超细粉制备的新方法，选择磷酸三丁酯（ＴＢＰ）－煤油－盐酸的工业化萃Ｚｒ体系，实验确定了反向胶团溶液形成的条件，即高酸度及相对较高的萃取金属离子浓废，并以氨水为沉淀剂使之与反向胶团溶液反应，将沉淀物洗涤干燥焙烧。     

碱性介质中元素硫歧化产物浸金的研究

本文在热力学分析的基础上，通过考察硫代硫酸盐，多硫化物等多种价态硫离子在金浸取过程中的作用，提出了从元素硫歧化产物浸金的工艺路线，并进行了实验验证。     

MASS TRANSFER IN TURBULENT PULSATING FLOWS

The effect of flow oscillation to the mass transfer between turbulent fluid and solid wall was investigatedby measuring the mass transfer rate between fluid and pipe wall with imposed oscillating flow usingelectrochemical method.The velocity and concentration field in the viscous sublayer which controls the mass trans-fer in such a process was simulated by a simple wave model of single harmonics.Experimental results confirmthat the flow oscillation has no influene on time averaged mass transfer rate,but the phase difference betweenphase averaged velocity field and concentration field shifts with the frequency of imposed oscillating flow.Numeri-cal analysis reveals that the concentration boundarylayer which is responsible for the mass transfer is muchthinner than the viscous sublayer which greatly weakens the influence of imposed oscillating flow on mass transfer.     

阶跃与方波示踪法测量气体的有效扩散系数

建立阶跃与方波示踪测量气体有效扩散系数的实验装置,并提出了扩散系数计算中所涉及的超越方程特征根的求解方法。采用稳态法,脉冲、方波和阶跃示踪动态法测量气体的有效扩散系数,对以扩散池为主体的各种实验方法进行评价。实验结果表明,当颗粒内的孔隙主要由大孔构成时,各种方法所得结果相近。阶跃与方波示踪法可以可靠地用来测量气体的有效扩散系数。     

INTERPRETATION OF FLOW NONUNIFORMITY AND HYSTERESIS WITH A CAPILLARY ARRAY MODEL

A novel capillary array model is proposed to shed light on the development of themaldistribution of cocurrent downward gas-liquid flow and the hysteretic performance behavior in apacked column.The model is based on the principle of nonequilibrium thermodynamics and incombination with lateral random walk of elemental liquid rivulets.The liquid distribution over aone-dimensional array of capillaries is simulated and the basic features of gas-liquid flow in packedbeds are demonstrated.With proper correspondence of hysteresis branches with nonuniformity of flowdistribution assumed,the experimentally observed hysteresis in pressure drop,liquid holdup and masstransfer rate can be qualitatively simulated.Strenuous efforts are still required for further developingthis model into a predictive tool for the evaluation of performance of packed-bed type devices.     

MECHANISM OF EXTRACTION AND STRIPPING OF Fe(Ⅲ) WITH PRIMARY AMINE N1923 AS EXTRACTANT AND n-OCTANE AS DILUENT

对伯胺—正辛烷萃取体系在萃取和反萃过程中有机相组成和水含量的变化用FTIR和光子相关谱进行分析研究。结果表明:伯胺与水相酸作用生成了阳离子型表面活性剂的结构,在有机相中易生成反相胶团。其萃取和反萃过程的实质是反相胶团内外的阳离子交换过程。Fe(Ⅲ)以水合形式萃取入有机相中,Fe(Ⅲ)的水解可能发生在反相胶团的微环境中。     

SOLVENT EXTRACTION OF Fe (Ⅲ) FROM SULFATE SOLUTIONS WITH TERTIARY AMINES

本文报道叔胺(TOA)从硫酸盐介质中萃取Fe(Ⅲ)的机理。研究了萃合物的紫外及红外光谱。根据实验结果提出了萃合物的可能结构形式。认为叔胺只能萃取部分水解的Fe(Ⅲ),而伯、仲胺既能萃取水解形式的Fe(Ⅲ)也能萃取非水解形式的Fe(Ⅲ),不同的条件下两种机理可以同时进行或相互转变。讨论了三类胺萃取Fe(Ⅲ)及硫酸反萃取Fe(Ⅲ)的性能的差别。     

EFFECT OF BACKGROUND REACTANT GRADIENT ON TRACER DISPERSION: A CASE STUDY OF IMPULSE INJECTION OF REACTANT INTO AN OPEN REACTOR

The paradox is well known that the residence time distribution(RTD)is not valid forthe estimation of the conversion of a first order reaction in an open tubular reactor.A casc ofδ injection of reactive species into an open flow system is investigated theoretically in this paper.The analytical solution with the Laplace transform demonstrated that the conversion of a first orderreaction is identical to that in a closed reactor under steady state.The effect of the backgroundreactant concentration gradient addressed by the authors in a previous paper was employed to thiscase.and the numerical solution of the tracer dispersion based on this novel argument gave rise to asimilar value of conversion.suggesting the validity of the concept and the significance of the subtledifference between RTDs determined with or without the presence of a background reactant in anopen flow system.     

滴流床中固相润湿分数的实验研究

用表面镇镇的填料颗粒催化过氧化氢分解的化学反应法，测定了内径75mm的滴流床中固体填料的外润湿分数实验结果表明，润湿分数随表现气速和液速的增加而增加，降低液体的表面张力、增大粘度也有利于提高润湿分数.当表现液速达到5kg／（m2·s）时，固体填料基本上完全润湿，这与文献报道和作者数值模拟结论一致．