第十九讲——电镀的安全生产与清洁生产(一)

介绍了氯化物镀锌液中硝酸根、铬酸根等阴离子,以及油污、光亮剂分解产物、表面活性剂等有机杂质的影响和去除方法。提出了减少有机杂质积累的若干措施,如坚持添加剂少加勤加的原则,控制好溶液组分(尤其是氯化钾和硼酸)和液温、pH等工艺条件,采用增溶性好的载体,以及研发新型光亮剂。     

正交实验法优化纳米二氧化硅与聚合硫酸铁的复配絮凝实验

研究表明,将纳米级二氧化硅与聚合硫酸铁复配后用于絮凝实验,较单一的聚合硫酸铁能更好地去除污水中的COD,本文以此为基础通过正交实验进一步优化了两者复配的实验室参数,并对各个影响因子进行了分析。     

锌酸盐镀锌液中的金属杂质及其对策

分析了锌酸盐镀锌液对金属杂质的敏感性.介绍了几种消除阳离子杂质的方法,如配位掩蔽法和沉淀去除法.讨论了乙二胺四乙酸、酒石酸钾钠、三乙醇胺等掩蔽剂的利弊,以及硫化钠沉淀法的可行性.指出了使用高纯度阳极的必要性.     

Workflow for managing impurities in an integrated crystallization process

A workflow consisting of experiments, modeling, and synthesis is presented for managing the impurity content in the product crystals of a crystallization process taking into consideration the entire train of crystallization and downstream processing steps. Experiments on solid–liquid equilibrium, impurity inclusion, washing, and deliquoring are designed in such a way that the experimental data or the model parameters derived from these data can be readily used for process design. Guidelines for experimental design and tradeoffs in process synthesis are discussed. The workflow is illustrated using the purification of Vitamin C (ascorbic acid) as a case study. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

HPO法生产己内酰胺工艺中杂质剖析

介绍了气相色谱法毛细管色谱柱分析己内酰胺中杂质的方法 ,采用质谱 -色谱仪联用 ,剖析了HPO法生产的己内酰胺中可能存在的杂质种类及杂质在生产工序中的分布 ,对己内酰胺生产工序中间物料及各种产品进行了定性分析。初步分析了杂质产生的原因 ,确定了己内酰胺中杂质主要产生于贝克曼重排反应     

Flocculation of fine particles in ceramic wastewater using new types of polymeric flocculants

It appears to be quite a few national and international studies were reported regarding flocculation and settling properties of ceramic industry wastewater containing various mineral matters. Cleaning of ceramic industry wastewaters with ever increasing environmental standards needs effective and economical solid–liquid separation processes. In this study, quantity and type of optimum flocculant concentration were investigated for solid–liquid separation of Umpac ceramic plant (located at Usak, Turkey) wastewaters. A new generation of flocculants namely unique molecular architecture (UMA) are used to obtain high settling velocity along with high solid content waste and circulation water with low turbidity values. Zeta potential of the tailings including quartz, feldspar, clorite, and mica was also measured at different pH values. The flocculation tests were performed in the presence of different types of polymers at different polymer dosages. It seems that Magnafloc 5250 shows higher performance than the anionic flocculant SPK 508 and other anionic UMA flocculants Magnafloc 6260 and Magnafloc 3230. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

镀铑液中铑和其它金属杂质的测定

介绍了镀铑液中铑的重量分析法--高纯锌粉还原法与仪器分析方法--电感耦合等离子发射光谱(ICP-AES).对这2种方法进行了对比,并且给出了ICP-AES法测定镀铑液中的微量铜、镍、铁、锌、铅等杂质的最佳测试条件.2种分析方法都具有准确、重现性好、相对标准偏差小的优点.     

自养脱氮工艺有机物去除段与硝化段精确分离的实现与实时控制

为了实现城市污水处理过程中的节能降耗,提出了三段式城市污水自养脱氮工艺,阐述了除有机物SBR在整套工艺中的重要地位,探讨了不同曝气量与污泥浓度条件下,除有机物SBR中有机物的去除特征与规律。结果表明,在不同的曝气量及污泥浓度条件下,COD降解结束前NO₂^--N与NO₃^--N的浓度均低于0.1 mg·L^-1,反应器进入COD难降解阶段后,NO₂^--N与NO₃^--N的浓度快速提高,可以认为在除有机物SBR内有机物的去除和硝化过程是分步进行的,即先进行有机物的去除,而后进行硝化过程。DO曲线与pH曲线的突越点与除有机物过程的终点始终保持一致,可将其作为实时控制参数监测有机物的去除终点,对好氧曝气过程进行实时控制。     

集成煤气脱萘与冷凝液回用的终冷工艺

新的终冷工艺集成了煤气冷却、煤气脱萘与煤气冷凝液利用,使煤气净化单元实现煤气梯级冷却。利用终冷器上段冷凝液作为脱氨工序的软水,可以减少焦炉煤气净化单元的剩余氨水量。终冷器利用洗油脱除煤气中的萘,含萘洗油经加热、油水分离后,送往洗苯-脱苯工序再生。     

马钢煤气脱萘新工艺的应用

对煤气脱萘的工艺、设备及能耗进行了研究。介绍了马钢开发的焦炉煤气脱萘新工艺,该工艺在横管初冷器内完成煤气的一步脱萘,煤气净化后不再设置其他脱萘工序。初冷器平均阻力在1000Pa以下,不用蒸汽清扫初冷器,煤气净化设备未发生萘的堵塞,每年可节约12000t标准煤,节能效果明显。     

干法乙炔脱硫

论述了干法乙炔生产中去除乙炔气体中H2S杂质的工艺计算和工艺指标的控制,解决了干法乙炔清净不合格的问题。     

头孢地嗪水溶液中降解杂质成分的检测及表征

应用超高效液相色谱串联质谱法分析头孢地嗪水溶液降解杂质成分。头孢地嗪水溶液经加热、酸碱及氧化破坏后,采用UPLC-MSE方法检测标准品及降解水溶液中杂质。依据保留时间、一级质谱母离子峰、二级质谱特征碎片分析确定头孢地嗪水解产物为反式异构体、Δ3异构体或其他降解杂质,加热、酸碱和氧化均会使杂质含量增加。头孢地嗪对热、酸、碱及氧均不稳定,样品应于暗晾干燥处密封保存,且注射溶液配制后应尽快使用。     

铬酸钠碱性液除钒工艺研究

采用无钙焙烧或湿法冶金工艺制备的铬酸钠碱性液,铬酸钠溶液中钒杂质已成为必须去除的杂质之一。研究探讨了羟氧化铬在铬酸钠含钒溶液中的除钒效果,考察了温度、羟氧化铬加入量、反应时间、溶液p H值等因素对除钒效果的影响。结果表明:每升铬酸钠溶液[ρ(V2O5)=0.600 g/L]需使用羟氧化铬40 g,在除钒温度60℃、时间30~120 min、p H值9~12的条件下,除钒效果较好。     

Statistical analysis of the removal of aluminum and magnesium impurities from wet-process phosphoric acid

The present paper relates to the treatment of crude wet-process phosphoric acid with ammonium nitrate and hydrofluoric acid to precipitate aluminum and magnesium impurities in the form of an easily separable phase: (NH₄)_xMg_yAl_z (F, OH)₆.2 H₂O. To check the effect of some concentration factors on this reaction, an orthogonal central composite design is realized with three variables: %Al³⁺, %NH₄⁺ and %F^?. It is concluded that the amount of aluminum in acid is the limiting factor of magnesium precipitation. Thus complete removal of magnesium, which is a major impurity in wet-process phosphoric acid, can be obtained by adding to the crude acid extra soluble aluminum salt simultaneously with hydrofluoric acid and ammonium nitrate.     

膜法脱硝技术改造

重庆天原化工有限公司的膜法脱硝装置经不断改进已实现经济平稳地运行。对试车、开车运行经验进行了总结。     

Flocculation of montmorillonite by some hydrophobically modified polycations containing quaternary ammonium salt groups in the backbone

The flocculating efficiency of some hydrophilic/hydrophobic cationic polyelectrolytes on montmorillonite suspension in water was investigated as a function of both the polycation structure and the flocculation parameters: polycation/montmorillonite contact time, suspension pH, polycation dose, and temperature. Cationic polyelectrolytes with quaternary ammonium salt groups in the backbone and hydrophobic side chains (hexyloxypropyl, PCA₅H₁ and PCA₅H₂; and decyloxypropyl, PCA₅D₁, respectively) were used as flocculants. The flocculation was time dependent. A negative influence of the stirring time and of the abrupt variation of pH from basic to acidic on the separation efficiency was evidenced. The increase of the polycation dose from 0.58 mg polycation/g montmorillonite up to 1.74 mg/g montmorillonite showed a positive influence on the sedimentation of montmorillonite particles for all the polycations taken into account. The influence of the polycation structure was reflected in the lower turbidity found in the case of the polycation PCA₅D₁ compared with that of PCA₅H₁, at the same concentration; this reflects the positive influence of the hydrophobicity increase on the suspension separation. A common characteristic for all the polycations is that, for more than about 60 min of settling, the lowest turbidity was found at 25°C and the highest at 5°C. The turbidity found at 15°C was in between, both before and after 60 min of settling time. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 871–876, 2002; DOI 10.1002/app.10371     

钙法脱硝运行总结

根据工艺需要以及试验和成本核算结果探讨了钙法脱硝工艺的可行性,并制定了实施方案,取得了很好的效果;改进后的工艺在运行过程中又发现了一些问题,再经改进,最终使工艺趋于完善。     

二甲基二烯丙基氯化铵聚合物的除浊性能研究

研究了二甲基二烯丙基氯化铵聚合物（PDMDAAC）系列絮凝剂对高岭土模拟水样的除浊效果及其影响因素；借助于微电泳技术，探讨了该系列絮凝剂的絮凝机理，并考察了其与PAC复配的除浊效果。实验结果表明：PDMDAAC系列絮凝剂具有优良的除浊效果，尤其对于高浊水；絮凝剂的特性粘度越高，阳离子度越高，除浊效果载好；PDMDAAC系列絮凝剂具有电中和和吸附架桥两种功能，与PAC复配，PDMDAAC系列絮凝剂可使除浊效果更佳而且可以降低处理成本。     

碱性无氰镀锌液的杂质去除技术

为解决碱性无氰镀锌液中杂质造成的质量问题,通过分析杂质来源,提出了处理方法。利用电解吸附原理,设计制作了专用于除杂的工具──电解除杂网。制定了镀液洁净度等级,介绍了去除杂质的操作方法。该技术效率高,成本低,操作简单,实现了对洁净度的可视化监控,且方便分等级处理杂质。     

铁盐法电絮凝联合除砷工艺的应用

介绍包头华鼎铜业发展有限公司铜冶炼烟气制酸酸性污水的处理及回用情况。酸性污水主要特点是砷含量高,采用铁盐中和沉降、过滤、电絮凝、物理吸附联合除砷除杂后,得到的洁净水砷质量浓度0.3 mg/L,其他指标均达GB 25467—2010标准。污水处理后全部回收使用,实现冲地水、制酸污水零排放。