杂质离子在EDI中的传质模型

该文介绍了EDI的工作原理，提出了水中杂质离子在EDI中的四个传质过程，即（1）杂质离子从水相到树脂相的传质；（2）杂质离子在树脂相中的传质；（3）杂质离子从水相互离子选择性交换膜的传质；（4）杂质离子在离子选择性交换膜内的电迁移传质。并推导出上述四个过程的传质速率方程，以利于进一步了解EDI的性能，便于EDI的推广应用。     

杂质离子对羟胺催化剂活性影响的研究

通过对羟胺反应液中的杂质离子对催化剂活性和选择性的影响进行实验测定,结果表明:羟胺反应液中的杂质离子中,非金属离子碘对催化剂活性影响最大,金属离子中铜对催化剂活性影响最大,多种离子对催化剂的毒性有积累性,杂质离子种类越多,对催化剂活性影响就越大,并总结多种杂质离子引起催化剂失活的规律,为工业生产中Pt/Pd-C催化剂的优化提供可靠的参考数据。     

离子交换法及其应用(三) 第三章 应用

§1.概述树脂广泛应用于各学科领域及工业生产中。就其作用分,大致可分为下列几种情况: 1.离子性杂质的除去离子性杂质能用离子交换树脂交换吸附除去。在一般情况下,溶液中的杂质离子有阳离子与阴离子两类,需联合使用H-型阳离子交换树脂与HO~-型阴离子交换树脂,将阳离子与阴离子同时除去(如制纯水、非电解质溶液中除离子),这通常叫做脱盐、去离子或去矿质。若杂质离子无需除尽时,叫做部分脱盐;另一情况是杂质只有一种离子(如KNO_2中混有KNO_3,杂质为NO_3~-离子),只需用一种离子交换树脂除去。除离子性杂质时,树脂型式的选择应依据     

盐水中的杂质对离子膜的影响

分析盐水中杂质对离子膜的影响,提出从水、硬件、工艺和原盐四方面避免盐水中的杂质对离子膜的影响.     

KNO_3熔盐中杂质离子对玻璃离子交换和增强的影响

利用电子探针和离子探针对KNO_3熔盐中一系列浓度的Ca~(2+)、Sr~(2+)、Ba~(2+)、Na~+杂质离子影响K~+-Na~+交换和离子交换玻璃的强度进行了研究。结果表明: 1.上述杂质离子对K~+-Na~+交换产生阻止效应和抑制效应。 2.扩散入玻璃的二价杂质离子,其浓度分布随在KNO_3熔盐中浓度变化呈极大值规律,并随这些离子进入玻璃和极化作用的加强,增大表面微张应力。离子交换玻璃的强度与二价杂质离子扩散规律直接相关。 3.KNO_3中含有二价杂质离子后,由于阻止效应和结构松弛的共同影响,使交换玻璃达到最大强度的处理温度大大提前。     

原盐质量对联碱生产的影响机理浅析

我公司采用原盐直接加入联碱生产系统的方法,原盐中杂质对生产影响很大。分析了原盐杂质中的钙镁离子、硫酸根离子对联碱生产的影响机理,并具体描述了杂质在生产过程中引起的不良影响。     

离子色谱法测定高纯度工业氢氧化钾中钠、钙、镁含量

本文采用离子色谱法(IC)测定高纯度工业氢氧化钾中钠、钙、镁杂质离子的含量。采用DionexACS1500型离子色谱仪,IonPacCS12A阳离子分离柱,用0.02mol/L甲基磺酸溶液为淋洗液,流速1.8ml/min,所含钠、钙、镁杂质离子得到很好的分离,利用峰面积对浓度的线性关系定量,效果良好。本法可以一次性同时检出需要严控的三种杂质离子,操作简单方便,灵敏度高、准确度好。     

湿法磷酸盐的技术经济指标评价:1.湿法磷酸中的杂质与湿法磷酸盐的关系

磷矿中的杂质以离子形态进入湿法磷酸(WPA)中,少量的离子生成沉淀物进入磷石膏中。对杂质离子给磷肥,饲料级、工业级与特种磷酸盐的质量影响,以及生成的副产物产量及其消耗或损失的P2O5量进行了分析。结果表明,无论采用何种方法除去WPA中的杂质,都不能改变杂质的性质,不会增减杂质的数量,不可能升降磷酸中阳离子在生产磷肥及磷酸盐时消耗的P_2O_5量。     

硫酸镁复合精制-氟化制备高纯氟化镁实验研究

杂质离子的存在会影响氟化镁在后续制备的氟化物玻璃、热压晶体等的应用,需要采取措施降低氟化镁中的杂质离子含量。同时为进一步降低原料成本,实验选用工业级硫酸镁为原料,通过对其进行复合精制、碳酸化、氟化获得了杂质离子含量符合要求的高纯氟化镁。硫酸镁的精制过程采用氧化还原与化学沉淀相结合的方式,用碳酸氢铵将精制的硫酸镁溶液碳酸化为碳酸镁,最后与电子级氢氟酸混合氟化得到高纯氟化镁。实验结果表明,采用此方法制得的氟化镁中铁、锰等杂质离子的质量分数均低于5×10-6,符合高纯氟化镁对杂质离子含量的要求。说明按照此方法制备高纯氟化镁是切实可行的。     

三价铬镀铬液中六价铬、铜、铁和镍杂质的分析方法

介绍了三价铬镀铬溶液中六价铬、铜、铁和镍杂质的分析方法。利用二苯氨基脲在酸性溶液中与六价铬的特效显色反应,用光度法测定三价铬镀铬溶液中的六价铬杂质。利用二乙基二硫代氨基甲酸钠与铜离子生成稳定黄棕色络合物的特性,用光度法测定镀液中铜杂质。利用钛铁试剂与三价铁离子在弱碱性条件下生成稳定的红棕色络合物的特性,用光度法测定镀液中的铁杂质。利用丁二酮肟与镍离子生成稳定的红色络合物的特性,用光度法测定镀液中的镍杂质。     

离子膜工艺盐水精制技术进展概述

介绍了盐水中杂质对隔膜和离子膜电解的不利影响,并概述了各种主要杂质的脱除方法,比较了优劣性.     

过氧化氢中无机杂质净化技术进展

综述了过氧化氢中无机杂质的来源和高纯过氧化氢生产中无机杂质的净化技术研究进展,这些技术包括：精馏法、离子交换树脂法、吸附法、结晶法、絮凝法、膜分离技术,以及这些技术的组合净化技术等.精馏净化产品纯度不高,但技术成熟,可工业放大;膜分离净化技术较安全,但膜的寿命短;离子交换树脂工艺简单,净化效率高,但树脂易被氧化.指出以精馏为前净化技术,再与膜分离、树脂法相结合是无机杂质去除技术的发展趋势.     

弱碱性阴离子交换树脂去除青霉素中的杂质

探索了用弱碱性阴离子交换树脂去除青霉素中的聚合物杂质。通过对树脂性能进行研究分析,将离子交换树脂应用于青霉素生产中,筛选出具有青霉素杂质去除能力的XX-16弱碱性阴离子树脂,通过树脂的选择性交换和吸附,将青霉素中的杂质进行有效吸附,有效降低了青霉素中的聚合物含量。     

Leaching characteristics and kinetics of the metal impurities present in rice husk during pretreatment for the production of nanosilica particles

Fundamental studies on the removal of metal impurities are essential for the production of nanosilica by combustion. This study reports the leaching characteristics, leaching kinetics and occurrence form of the metal impurities present in rice husk based on acid pretreatment. Acid pretreatment removes most of the metal impurities present in rice husk. In particular, 98 wt% removal of potassium can be reached. The acid concentration, leaching time and reagent type have significant effects on the leaching of metal impurities, and optimal conditions exist for the acid pretreatment process. Furthermore, the leaching of metal impurities occurs through two stages, and parts of the metal impurities exist in organic-bound form, which can be leached through ion exchange. The results show that the pseudo-second-order model is suitable for describing the leaching kinetics of the metal impurities present in rice husk, and empirical formulas for predicting the metal contents leached from rice husk during acid pretreatment at ambient temperature are also obtained. Additionally, the different occurrence form and quantities of metal impurities in rice husk lead to different leaching effects, which strongly influences the chemical properties and quality of the obtained silica particles.     

Impurity effects on crystallization of KCL from aqueous solutions in a MSMPR crystallizer

Extensive experimental investigations into the effect of magnesium and sulfate ionic impurities on cooling crystallization of KCl were carried out in a steady-state Mixed Suspension Mixed Product Removal (MSMPR) crystallizer. The impurities selected for investigation were chosen from those naturally associated with KCl in potash industry. Eighty one experiments were performed in a factorial experimental design scheme. The results exhibited that magnesium ion did not have any significant influence upon crystallizations of KCl, while the sulfate ion enhanced the aggregation rate. The nucleation rate was only slightly affected by the presence of impurities. The size enlargement in presence of sulfate ion was ascribed to an increase in aggregation rate. It was demonstrated that the role of the impurities studied upon KCl crystallization is consistent and predictable and is a function of the chemical character of the impurity species. Based on these results two mechanisms for size enlargement were identified, first due to crystal growth by solid deposition and second due to aggregation. Aggregation was found to be the governing mechanism for producing large crystals.     

Prospective n-type impurities and methods of diamond doping

A major goal of diamond thin film technology research has been the reproducible production of p-n junctions, which are the basic units of many electronic devices. While p-type conductivity is relatively easily attained by boron doping, n-type conductivity has proved much harder to achieve. The experimental and theoretical results on prospective donor impurities are reviewed. In analogy with classical semiconductors, we will discuss the possibility of obtaining n-type diamond by using substitutional impurity atoms (nitrogen and phosphorus) and interstitial atoms (Li and Na).

New methods of forced diffusion and ion assisted doping during growth are discussed. Methods of forced introduction of impurities into the diamond lattice have an important advantage over traditional ion implantation methods. Ion implantation introduces structural defects (vacancies, vacancy + interstitial, and their combinations) that are difficult to cure. Both methods, forced diffusion and ion assisted doping during growth, introduce no additional structural defects, except that inherent to the impurity itself.     

FM21型离子膜电解槽问题分析

针对FM21型离子膜电解槽运行中离子膜穿孔、进槽盐水供应故障,检修后送电前盐水杂质含量多,停槽时阳极液中有效氯含量多、碱液中铁和盐含量高等问题,提出了应对措施。     

Mechanisms of oxidative degradation. I. Oxidation of synthetic rubbers catalyzed by metallic ions

The oxidative stability of rubbers depends on the structure of the rubber and the impurities contaminating the rubber. It is known that the oxidation of natural rubber is accelerated by the presence of metallic impurities. Besides GR-S rubber and nitrile rubber, the effects of metallic impurities on the oxidation of new rubbers, especially those introduced after the discovery of Ziegler-Natta catalyst, have not been reported. In the first part of this paper, the theoretical background on the mechanisms of metalcatalyzed oxidation is given. Most of the early work was carried out for the oxidation of hydrocarbons in the liquid phase. The difficulties in applying the liquid-phase results to the oxidation of high polymers in the solid phase are mentioned. The new rubbers used for this study are polyisoprene, polybutadiene, cis-poly-1,3-butadiene, styrenebutadiene copolymer, butyl rubber, ethylene-propylene terpolymer (EPT), propylene oxide rubber, polyacrylic rubber, and butadiene-acrylonitrile rubber. The effects of stearic acid and various stearates on the oxidation of these rubbers are presented. The number of electrons transferred by the metal ion during redox reactions was found to be related to the effectiveness of the ion as a catalyst. Both the high and low oxidation states of the metal ion were shown to be active catalysts, supporting the accepted theory of metal catalysis through a hydroperoxide decomposition mechanism.     

高浓度镀铬废水的处理研究

利用分步中和－沉淀方法去除高浓度镀铬废水中重金属离子杂质。处理后高浓度镀铬废水可供化工厂生产铬黄。     

脱除苯酚中微量杂质的工艺技术进展

简要介绍了苯酚精制过程中含有微量的有机杂质异亚丙基丙酮、羟基丙酮、苯并呋喃的形成机理,及其对苯酚产品质量的影响,并概述了分别使用水滑石型材料（HTM）、ⅥA族金属改性的氧化铝、沸石、酸性离子交换树脂为催化剂的一步苯酚精制法和使用酸性树脂＋闪蒸法和两步固体酸法的两步精制法脱除苯酚中羟基丙酮、亚丙基丙酮、苯并呋喃等微量有机杂质的生产技术的新进展。