A microcomputer-controlled facility for the analysis of phases from the AKUFVE mixer-centrifuge unit

An AKUFVE mixer-centrifuge unit is used to collect distribution data for plutonium and uranium in a nitric acid/tributyl phosphate system under various conditions. The equipment necessary to make on-line measurements in both phases and to perform off-line titrations of the nitric acid is described. An explanation is given or the design of the Control Program. Written in BASIC with a few machine code subroutines, the program executes blocks of code of ‘sequences’ corresponding to particular functions. There are a dozen sequences which may be called in any order or individually to perform these functions.     

Separation of Copper and Zinc by Solvent Extraction During Reprocessing of Flotation Tailings

Results from the solvent extraction of copper and zinc from pregnant solutions after bioleaching of re-floated tailings from the Kipushi concentrator in DR of Congo are presented. LIX984N has been used as extractant for copper, while D2EHPA as such for zinc, following prior removal of the ferric iron via precipitation. The McCabe-Thiele diagrams constructed for Cu and Zn extraction have theoretically suggested the need for two stages for copper and one for zinc. Stripping these metals to the aqueous phase by sulphuric acid has yielded rich electrolytes with 48.5 g/L copper and 85.5 g/L zinc. Thus, copper and zinc could be further recovered from the stripped solutions by electrolysis.     

钨萃取平衡分配比的研究

使用一套溶剂萃取平衡的试验装置,选择膦酸三丁酯（ＴＢＰ）为萃取剂,苯为稀释剂,系统地测定了钨的溶剂萃取平衡及萃取条件对萃取平衡分配的影响,可为工业过程设计、工程优化和计算机模拟提供依据。     

油砂溶剂抽提实验研究

对新疆油砂使用溶剂萃取法进行处理,选用93#汽油作为溶剂进行正交实验和单因素实验,通过对比萃取前后油砂显微结构对油砂萃取理论进行研究。实验表明油砂粒径、萃取时间、萃取温度、剂砂比对油砂萃取率的影响依次降低。当萃取时间30min、萃取温度80℃、油砂粒径小于450μm(中位粒径268μm)和剂砂比为4∶1时,萃取率可达到90%,尾砂含油率为1.7%。     

Extraction of Non-Ferrous Metals and Iron with Systems based on Bis(2,4,4-Trimethylpentyl)Dithiophosphinic Acid (CYANEX 301), A Review

Extraction is widely used in the hydrometallurgy of nonferrous metals. In addition to such well-known extractants as oxygen-containing organophosphorus or monocarboxylic acids, thio-substituted organophosphorus acids in particular, the commercially available extractant CYANEX 301, the active component of which is bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HR), is of interest. This extractant is a sulfur-containing analogue of CYANEX 272 (bis(2,4,4-trimethylpentyl) phosphinic acid). In this review, the state of CYANEX 301 in various solvents in the absence and presence of electron-donor additives, the chemistry of the extraction processes of non-ferrous metals in the HR systems, the compositions of the extracted compounds, stability of the extractant in aggressive media, technological developments, and prospects for using CYANEX 301 in hydrometallurgy of non-ferrous metals are discussed.     

An Overview of the Physiochemical Nature of Metal-Extractant Species in Organic Solvent/Acidic Organophosphorus Extraction Systems

The interfacial behavior of metal-extractant species in the liquid/liquid extraction of metal ions still remain incompletely understood at the molecular level under high loading conditions. Traditionally, metal-extractant complexes in the organic phase under dilute conditions have been characterized by slope analysis. At high loading, the metal-extractant aggregates structure appears to change. The metal-extractant aggregates have been described as either polymers or reversed micelles. This behavior is difficult to confirm by direct experimental measurements. Recently, molecular modeling was used to study the molecular structure of metal-extractant aggregates. The study confirmed that the metal-extractant species are reversed micelles at high loading conditions.     

An application of a cascaded self tuning regulator to a karr solvent extraction column

An application of a cascaded Clarke-Gawthrop self tuning regulator (STR) to a Karr liquid-liquid solvent extraction column is presented. The Karr column, a reciprocating plate column, exhibits nonlinear asymmetric responses which are complex functions of the operating conditions and requires adaptive control in order to prevent instability. The outer loop of this cascade scheme controls the extract concentration of the continuous phase while the inner loop controls the hydrodynamic holdup in the column and prevents flooding. The manipulated variable was the frequency of reciprocation. The STR-STR cascade arrangement is compared with a fixed parameter Proportional plus Integral (PI) controller in the outer loop and an STR in the inner loop.     

Synergistic effects in the solvent extraction of some divalent metals by mixtures of versatic 10 acid and pyridinecarboxylate esters

Pyridinecarboxylate esters were found to cause appreciable synergistic shifts in the pH₅₀ values for the extraction of some divalent base metals by solutions of Versatic 10 acid in xylene. For n-octyl 3-pyridinecarboxylate, the synergistic shifts decreased in the order Ni > Co > Cd > Cu ≈ Fe > Mn > Zn, and for the commercial extractant Acorga DS5443A in the order Ni > Cu > Co > Fe > Cd > Mn > Zn. No synergistic effects were observed for divalent lead, calcium and magnesium. On the basis of the pH₅₀ values obtained, several possible practical metal separations are suggested. No loss of metal-loading capacity was found when the organic phases were contacted with 1 M sulphuric acid for prolonged periods at 30°C. The effect of changes in the structure of a series of isomeric octyl pyridinecarboxylates is reported for one of the smaller cations studied (copper), as well as for one of the larger cations (cadmium).     

Control of mass transfer and hydrodynamic holdup in a karr solvent extraction column

This paper reports an experimental application of multiloop control to a Karr solvent extraction column (a reciprocating plate column). The control objective was to keep the extract outlet concentration above some minimum level and to maintain a high value of dispersed phase holdup while keeping away from the flooding point. Transfer function models were identified from step tests about a nominal operating point and various interaction/operability analysis techniques were used to synthesize a control scheme. The control implemented in this study was a model inversion based scheme in which the extract outlet concentration was controlled by manipulating the continuous phase superficial velocity and the dispersed phase holdup was controlled by manipulating the frequency of reciprocation. Both servomechanism and regulatory responses are presented. A variable dead time Dahlin controller was used to control the extract outlet concentration and a Clarke-Gawthrop self tuning regulator was used to control the dispersed phase holdup. This multiloop control scheme is compared to single loop control of the extract outlet concentration.     

乙烯装置急冷油系统研究进展

介绍了近年来乙烯装置急冷油减黏工艺与减黏剂的研究最新进展，对不同的减黏工艺进行了比较，评述了国内外减黏剂的研究现状和机理。     

闭式涡轮搅拌萃取塔液滴直径的估算

本文利用均匀各向同性湍流特性分析连续相湍流脉动液滴大小的影响,得出搅拌强度和液滴平均直径之间的关系,根据所使用的三种塔几何结构所得的实验数据检验。理论分析结果与实验所得结果较好地相符。本文也讨论了分散相存留分数对平均液滴直径的影响。     

有机磷(膦)酸对碱土金属的萃取

Solvent extraction equiliria of four main alkaline earth metals (magnesium, calcium, strontium and barium) with di(2-ethylhexyl) phosphoric acid (DEHPA), 2-ethylhexyl phosphonic acid mono-(2-ethylhexyl) ester, di(2,4,4-tri-methylpentyl) phosphinic acid and IR spectra of the extracts have been studied. The selectivity order is dependent of the e/r value and hydration energy of the metal ions. The minor shift of the P→O in IR absorption of the alkaline earth metal extracts indicates that the interaction between the metal ions and P→O is much weaker for alkaline earth metals than for transitional metals. The distribution of the four alkaline earth elements between aqueous solutions and solutions of DEHPA and neutral organophosphorus compunds, tri-n-butyl phosphate (TBP) or tri-octyl phosphine oxide (TOPO) in kerosene have been determined at varying ratio of TBP or TOPO to DEHPA and the positive synergism is observed. The synergic effects is explained by using IR spectra of the loaded organic phase.     

玻璃原料及配合料的控制

简述了浮法玻璃硫酸盐的澄清机理,介绍了玻璃原料COD值的分析方法及影响因素,主要介绍了玻璃Redox的控制原理及计算方法。     

Glutathione is a key player in metal-induced oxidative stress defenses

Since the industrial revolution, the production, and consequently the emission of metals, has increased exponentially, overwhelming the natural cycles of metals in many ecosystems. Metals display a diverse array of physico-chemical properties such as essential versus non-essential and redox-active versus non-redox-active. In general, all metals can lead to toxicity and oxidative stress when taken up in excessive amounts, imposing a serious threat to the environment and human health. In order to cope with different kinds of metals, plants possess defense strategies in which glutathione (GSH; γ-glu-cys-gly) plays a central role as chelating agent, antioxidant and signaling component. Therefore, this review highlights the role of GSH in: (1) metal homeostasis; (2) antioxidative defense; and (3) signal transduction under metal stress. The diverse functions of GSH originate from the sulfhydryl group in cysteine, enabling GSH to chelate metals and participate in redox cycling.     

Pseudohydroxide Extraction from Aqueous Sodium Hydroxide Solutions with 3,5‐di‐tert‐Butylphenol in Isopar® L Modified with 1‐Octanol

Abstract

Pseudohydroxide extraction (PHE) was investigated for recovering sodium hydroxide (NaOH) from alkaline process solutions. PHE relies on the deprotonation of a lipophilic weak acid by hydroxide ion with concomitant transfer of sodium ion into an organic phase. Contact of the sodium‐loaded organic phase with water results in the reconstitution of the extractant in the organic phase and NaOH in the aqueous phase, thus leading to a process in which NaOH equivalents are transferred from an alkaline feed solution to an aqueous stripping solution. In this work, we investigated PHE using a process‐friendly diluent—Isopar^® L. The lipophilic cation exchanger 3,5‐di‐tert‐butylphenol (35‐DTBP) was used as the extractant. The Isopar^® L diluent was modified with 1‐octanol to improve its solvation properties and the solubility of 35‐DTBP so that practical Na⁺ concentrations could be achieved in the process solvent. The PHE mechanism at process‐relevant conditions was explored by Raman and Fourier transform infrared spectroscopic measurements. Complementary electrospray ionization mass spectrometry studies were also performed. Equilibrium computer modeling suggested that the Na⁺ extraction behavior can be largely explained by the formation of 1∶1 and 1∶2 Na/35‐DTBP species in the organic phase. Extraction isotherms obtained using simulated caustic leaching solutions indicate the potential utility of this approach for recycling NaOH from complex alkaline mixtures.     

天然表面活性剂卵磷脂的提取

利用溶剂萃取法从大豆粗磷脂中提取得到了天然表面活性剂卵磷脂,研究了影响卵磷脂得率的各种因数,得到较佳工艺参数。