DESIGN OF SOLIDS SEPARATION PROCESSES CONSISTING OF IDENTICAL STAGES

The separation of the constituent minerals of an ore is never achieved in one stage. It is carried out in multiple stages incorporating recycling of streams to increase the recovery of the required mineral. This paper outlines a methodology for designing a separation process system consisting of nonsharp separation stages and involving recycles and mixtures instead of pure component as products.

For given technical and economic criteria the regions of optimal configurations on the grade versus flowrate diagram have been recognised. This diagram is used for the selection of the optimal circuit configuration for given feed flow, feed composition and separation characteristics. The minimum economically processable grade of the feed has been identified. This allows a decision to be made about an ore deposit as to whether it carries potential value for further processing or not. The maximum economically achievable grade has also been identified. This places a limit on the upgrading of the product for maximum profit.

The paper reports a number of case studies from the view point of application perspective, using the grade-flowrate diagram, and compares this work with the work of Chan and Prince. This comparison provides essentially the same results as the work of Chan and Prince. Sensitivity analysis in regard to the use of parameter values is another key aspect of this paper. The effects of various technical and economical parameters on the grade-flowrate diagram have been studied in this particular paper.

Results obtained from different case studies show that the present study offers an effective means for design engineers to make an initial selection of a process configuration for stagewise separation processes prior to the detailed flowsheet design.     

P-950哌啶树脂分离金和钯

研究了盐酸浓度、氯化钠浓度、金和钯的起始浓度、选择性络合剂及温度等因素对Ｐ－９５０树脂分离金和钯的影响．结果表明，在适宜的盐酸浓度和有氯离子存在的条件下，该树脂能优先吸附金．提高温度有利于金与钯分离．用有机醛、酮为络合剂（ＲＯ）可从载有金和钯的树脂上选择性解吸金，而钯不被解吸，从而达到金和钯分离的目的     

肌苷发酵和分离耦合过程的动力学

许多发酵过程都受到高浓度产物的抑制,肌苷发酵亦存在明显的产物反馈抑制作用。为了降低产物抑制效应,采取发酵和离子交换分离产物、流加补料结合起来的耦合发酵方法。本文结合肌苷合成代谢途径,建立了肌苷耦合发酵动力学模型,用于指导工业生产。     

CALCULATION METHODS FOR DISTILLATION SYSTEMS WITH REACTION

A calculation procedure is presented for the solution of the equations describing a distillation process in which reaction is taking place. A mathematical model based on matrix notation is used to formulate the system equations. It is assumed that the distillation process can be represented by a system of interconnected stages, each of which is well mixed with the vapor and liquid phases in equilibrium. Reaction may take place in the vapor phase, liquid phase, or both. The equations describing this system are first presented. Then a calculation sequence and a correction algorithm are derived for the case in which the liquid and vapor solutions are ideal—that is, the equilibrium ratios are functions only of temperature and pressure and not of composition. The calculation sequence uses as variables of iteration the vectors of vapor flow rate, temperature, and reaction extents. A derivative correction method is used, and equations for the calculation of the Jacobian matrix are derived. The application of the method is illustrated by solution of two sample problems. The special case in which the heat of reaction is small, and constant molal overflow can be assumed, and the case in which the reaction rate is very fast and chemical equilibrium exists in each stage are considered.     

CFRP-PCPs筋内嵌加固混凝土梁抗弯刚度及截面内力分析

进行了8根CFRP-PCPs复合筋内嵌加固混凝土梁的加载试验研究。结果表明,与预应力CFRP材料的其他加固方式相比,采用预应力CFRP-PCPs筋内嵌加固混凝土梁可有效提高加固梁的刚度。依据试验荷载-挠度关系曲线,建立了三直线弯矩-曲率关系模型,并推导出了CFRP-PCPs筋内嵌加固混凝土梁短期刚度与挠度计算公式,将计算值与试验值进行对比,吻合度良好。     

果糖的应用特性及其分离

简要介绍了果糖的特性和应用特点，以及用模拟移动床吸附分离技术分离果糖的国内研究开发情况。     

ON LINEAR PROCESSES WITH GIVEN MOMENTS

Abstract. Let X _t = c ₀ Y _t + c ₁ Y _{t -1}+… be a linear process with known coefficients c _k , where Y _t is a strict white noise. Let m ₁, …, m _2r be given numbers. A method is presented to determine whether there exists a distribution of Y _t such that EX ^k _t = m _k for k = 1, …, 2 r . In the positive case, such a distribution of Y _t is described. Some explicit formulas for AR(1) and AR(2) models are derived. The results can be used for simulating a process with given moments of its stationary distribution. The procedure also enables proof that some stationary distributions cannot belong to the given linear process.     

SEPARATION OF o AND p CHLORONITROBENZENES THROUGH HYDROTROPY

Hydrotropic solutions can be used in separation of two isomers as hydrotropes at high concentrations can enhance solubilities of these isomers in aqueous solution differently. Solubility data are determined for o and p chloronitrobenzenes (CNBs) in aqueous solutions of sodium butyl monoglycol sulphate (NaBMGS). o CNB is highly solubilized as compared to p CNB and can be precipitated out selectively on dilution with water at a reasonable recovery. Precipitation kinetics of p CNB determined from a solvent capacity varying batch crystallizer using the method of s plane analysis show that the relative order with respect to linear growth rate in conventional power law relative nucleation correlation is near unity.     

空分装置的模拟与调优计算

利用ＡｓｐｅｎＰｌｕｓ软件作平台,建立了空分精馏系统的计算模型,以齐鲁二化空分装置的设计值及５种有代表性的实际操作工况进行模拟计算,计算结果分别与设计值及实际工况值吻合较好。并以提高氧气产量为目标,对５种工况进行模拟调优研究,找出提高氧气产量的途径,在不增加空气量的情况下,可提高氧气产量１５％左右。     

OPTIMAL POLICIES OF A LIQUID CHROMATOGRAPHY SEPARATION

A simulation model of a chromatographic separation is used to define an objective function representing the system performance, which is oplimized by transforming an optimal control problem into a nonlinear programming problem. The decision variables of the problem are the injection time period, the cycle time and the switching times for the production cut of each key component. The objective function is either the product recovery to be maximized, or the off-cut collection to be minimized.

Two numerical examples are presented in order to illustrate this' approach: the separation or a binary mixture and the purification of one key component in a ternary mixture. In each case, an extensive sensitivity analysis of the optimal solution is presented.     

中空纤维He-CH_4膜分离器分离性能的研究

以He-CH_4二元混合气体为被分离体系,对由中空纤维型醋酸纤维膜与毛细管型硅橡胶膜构成的单膜分离器和由此构成的连续式双膜分离塔进行了实验研究;探讨了有关参数及流型对分离器分离性能的影响;测试、关联及分析了渗透系数和分离因子随气体操作条件改变的变化规律;用作者建立的理论模型对所有的实验点进行了验证。     

有固相析出的顺流多效蒸发过程热量衡算

在齐－柯法的基础上，提出了一种有固相析出的顺流进料多效蒸发过程热量衡算方法，并结合相图给出了蒸发过程物热衡算的逐步逼近计算步骤。     

THE DEPOSITION OF REJECTED MATTER IN MEMBRANE SEPARATION PROCESSES

The mechanism by which particles rejected at a membrane filter that is operated in cross-flow are returned to the feed stream has remained unclear. Comparisons with concentration polarization during molecular rejection raise difficulties because molecular diffusivities are much larger than those considered plausible for particles. In the present work particles are postulated not to return to the bulk but rather to flow along the surface of the membrane in a layer whose thickness increases in the direction of feed flow. A model for both the steady and transient case is solved using the method of characteristics. The role of the rheology of the close-packed layer is emphasized.     

THE DEPOSITION OF REJECTED MATTER IN MEMBRANE SEPARATION PROCESSES

The mechanism by which particles rejected at a membrane filter that is operated in cross-flow are returned to the feed stream has remained unclear. Comparisons with concentration polarization during molecular rejection raise difficulties because molecular diffusivities are much larger than those considered plausible for particles. In the present work particles are postulated not to return to the bulk but rather to flow along the surface of the membrane in a layer whose thickness increases in the direction of feed flow. A model for both the steady and transient case is solved using the method of characteristics. The role of the rheology of the close-packed layer is emphasized.     

酶促反应色谱分离耦合过程参数分析

对酶促反应以谱分离耦合过程进行了反应动力学参数及操作参数分析,并以蔗糖酶促水解为模型反应进行了正交实验研究,结果表明,该耦合过程对产物非竞争性抑制的消除效果要优于竞争性抑制。产率对底物浓度最为敏感,其次为洗脱速率和进料体积,而转化率的敏感性次序由大到小依次为洗脱速率,底物浓度和进料体积。     

SEPARATION OF m-XYLENE FROM o-XYLENE BY EXTRACTIVE DISTILLATION

m-Xylene is difficult to separate from o-xylene by rectification because the relative volatility is only 1.12. m-Xylene can be separated from o-xylene using extractive distillation in which the extractive agent is composed of the proper higher boiling organic compounds. Typical effective agents are benzoates, DMSO, DMFA, adiponitrile, maleic anhydride, phthalic anhydride, polychloroaromatics and sulfolane.     

COBALT-NICKEL SEPARATION BY SOLVENT EXTRACTION WITH BIS(2,4,4 TRIMETHYLPENTYL)PHOSPHINIC ACID

Abstract

The use of an organophosphinic acid to separate cobalt from nickel by solvent extraction is described. Comparative data indicate that the phosphinic acid is superior to analagous phosphoric and phosphonic acids in terms of cobalt-nickel selectivity and the ability to reject calcium. Important reagent properties, such as low aqueous solubility and hydrolytic stability, are discussed. The results of continuous, counter-current, mini-plant tests demonstrate the recovery of high purity cobalt from concentrated nickel sulphate solutions.     

格法0.7 mm超薄玻璃生产实践

总结了0.7 mm超薄玻璃格法生产实践的成功之处,介绍了生产中原料、熔制及引上工艺采取的措施,分析提出了0.7 mm玻璃生产中的难点和关键问题以及部分建议.     

A SIMPLE APPLICATION OF MURPHREE TRAY EFFICIENCY TO SEPARATION PROCESSES

Vapor-liquid equilibrium is predicted by using the Soave modification of the Redlich-Kwong equation of state (EOSrpar;. The concept of equal fugacities is used to calculate the equilibrium constant, K₁ = y₁/x₀, then, it is shown how the Murphree tray efficiency can be applied on the liquid or the vapor phases to modify that constant. The derivatives needed are calculated numerically, and it is shown that for absorbers and distillation columns, Murphree tray efficiency applied this way can be used to simulate the actual number of stages

Murphree tray efficiency values can be specified for one, several or all of the components on any stages of a column

A dehydration example is shown, the dew point depression values of a mixture of water-gas, using a triethylene glycol solution for dehydration purposes, are calculated by incorporating the method into a process simulator program called PROSIM® and compared with the values reported in the literature.