集成膜法回收硫酸稀土溶液中硫酸

对减压膜蒸馏浓缩硫酸稀土溶液和与扩散渗析联合回收低浓度的硫酸做了研究．结果表明,水通量随着溶液中稀土及硫酸浓度的增大而减小,随温度升高、减压侧压力降低及料液流速增大而增大;先用减压膜蒸馏法浓缩硫酸稀土溶液,再用扩散渗析法回收硫酸对稀土截留率基本无影响,但大大增高了回收液硫酸的浓度,减少了扩散渗析的处理量,而浓缩倍数越大则效果越明显．     

扩散渗析法回收硫酸稀土溶液中硫酸研究

对扩散渗析法回收硫酸稀土溶液中硫酸进行了实验研究,结果表明,料液中稀土浓度0～0．2mol／L范围内的较小变化对硫酸回收率没有明显影响;料液流量越大,即设备单位膜面积处理能力越大,硫酸回收率越低,回收液硫酸浓度及稀土截留率也越低,控制硫酸回收率在70％～80％较为合适;水料流量比越大,硫酸回收率越大,但回收液硫酸浓度及稀土截留率均降低,控制水料流量比在1左右较为合适;扩散渗析法能达到有效回收硫酸稀土溶液中硫酸的目的．     

提高漂定液银回收效率的新方法

本文介绍废漂定液银回收的电解法。一般来说,回收漂定液白银的电解法有两种:1.高密度的电流(10安/分米~2)电解法。电解时,白银和铁离子同时在电解槽中通过阴极还原;电解效率低(18%)。2.低密度电流(1安/分米~2)电解     

扩散渗析回收含铜退镀液中的硝酸

采用扩散渗析法回收含铜退镀液中的HNO3,考察流量、流量比、温度等因素对硝酸的回收率、回收液中硝酸浓度以及铜和镍离子截留率的影响.将单级扩散渗析仪改装成新的三级扩散渗析仪,考察了三级逆流扩散渗析对实验结果的影响.单级扩散渗析的结果表明,最佳条件:水/料的流比为1∶1、流量90 mL/h、温度19℃,其硝酸回收率为86.95％、回收浓度6.04 mol/L、Cu2+和Ni2+的截留率分别为90.19％、92.71％.相对于单级扩散渗析,自行改装的三级扩散渗析过程能达到更高回收酸浓度和单位时间内处理更多的料液.在含铜退镀液体系下,利用国产扩散膜实现了扩散渗析对于H+和金属离子具有良好的分离,同时达到了回收硝酸浓度高于原退镀液的效果.     

单膜双室同槽电解金属锰联产EMD离子的传输机理研究

针对传统布式隔膜袋电解技术工艺中存在的诸多弊端,本研究提出了单膜双室膜电解工艺,以MnSO4+(NH4)2 SO4为电解液体系,实现在阴极产锰的同时在阳极联产电解二氧化锰,并在阳极室中回收硫酸.通过测定阴阳极室中各离子成分的变化情况,来深入分析电解过程中的离子传输行为,以验证单膜双室同槽电解的技术可行性.实验结果表明:单膜双室电解法能够有效实现同槽电沉积金属锰并联产电解二氧化锰,同时在阳极室中回收硫酸,硫酸浓度可达1.5 mol/L,满足前端锰矿酸浸工艺要求,促进了对资源的高效回收利用.采用TRJAM-10W阴离子交换膜的阴极产锰率和阳极酸回收率最高,分别可达77.0％和64.3％,而采用Ionsep-HC阴离子交换膜的阳极产EMD率最高,为27.3％.TRJAM-10W阴离子交换膜的槽电压最小,为4.43 V,其电能消耗也最低,为5607 kW·h·t-1.     

堆浸贫液除杂回用工艺生产实践

通过氰化贫液进行酸化、氧化、吸附的处理,去除了贫液中有害杂质,使贫液满足了回收利用的要求,提高了浸出效果,降低了生产成本,减少了环境污染,并取得了一定的经济效益。     

一种黄金冶炼贫液及氰化尾渣处理新技术

该文介绍了黄金冶炼贫液、氰化尾渣资源回收和无害化处理新技术的研究和应用。首先通过对贫液的预处理,回收贫液中的有价锌和铜金属离子,提高了处理后贫液中氰化钠的含量。贫液处理改善了氰化厂系统循环液的水质,进一步降低了氰化尾渣中总氰化物的含量。再将氰渣进行调浆,采用新型氧化剂对氰渣进行破氰处理,消除氰根离子对硫精矿浮选的抑制作用,最后直接浮选硫精矿和铜精矿,剩余的尾渣为高硅渣,经过鉴别后可以达到一般固体废物的标准。     

铝或铝合金的光亮电解着色

方法包括:(1)在硫酸溶液中阳极氧化铝(合金)基体。(2)在含硫酸、硝酸、氨基磺酸和/或硫酸氢铵溶液中交流电解。(3)在含硼酸、硼酸铵、酒石酸、柠檬酸或乳酸等的溶液中阳极电解形成保护涂层。(4)在含金属盐的电解着色液中电解。     

膜电解再生氨性含铜蚀刻废液及氯化亚铜制备技术研究

试验利用膜电解分离技术对氨性含铜蚀刻废液的再生开展了相关研究工作,考察了槽电压、阳极液pH值、电解时间等因素对膜电解电流效率的影响,并确定了最优电解条件:槽电压2.80 V、阳极液初始pH为9.07、电解时间3.0 h时,此时电流效率可达94.0%.电解后的阴极液用于制备氯化亚铜,试验得出最佳制备工艺条件:水解反应温度为20℃,按理论反应摩尔比为1:1.056的比例加入亚硫酸钠,再加入阴极液体积1.2倍的HCl(1:1)溶液调节溶液pH为3.5,稀释倍数为11的条件下,氯化亚铜产率达到64.32%,纯度为99.13%.试验结果表明该工艺操作方便、简单可行,是处理蚀刻废液、回收铜的有效方法,具有一定的应用价值.     

镍镉合金扩散层工艺研究

为满足飞机发动机叶轮耐高温腐蚀要求,研究了镍镉合金扩散层的结构,同时分析了镍镉合金镀液工艺参数对扩散层性能的影响.采用合适的电解镍液或化学镀镍液的配方来制取低应力镍层;采用液体喷丸方法提高零件表面强度及抗摩力腐蚀能力.结果表明,该两种方法有效克服了镍镉合金扩散层不耐疲劳和高温应力腐蚀的弊病,即使在工作中承受旋转、弯曲、振动、离心等复杂应力作用的镍镉扩散层,也具有优良的性能.     

Formation of formic acid,acetic acid and lactic acid from decomposition of citric acid by coal ash particles at room temperature

It was found for the first time that citric acid was decomposed to formic acid, acetic acid and lactic acid in the presence of coal ash particles at pH 3 at 20 °C, while it was not decomposed at more than pH 5. The yield of organic acid at stirring time of 60 min is in the order of formic acid > acetic acid > lactic acid. Since citric acid dissociates to citric anion at more than pH 5, it was suggested that citric anion and negatively charged coal ash particles repelled electrically each other at more than pH 5, resulting in that citric acid could not be adsorbed and not be decomposed on coal ash. Based on the obtained results, the decomposition of citric acid at pH 3 was suggested to be due to catalytic effects of coal ash. Since formic acid and acetic acid can be used as a material of hydrogen fermentation, coal ash could be used as a catalyst to synthesize the important material for hydrogen fermentation from wastewater of citric acid.     

马来酸异丙酯-丙烯酸二元共聚物的合成研究

以马来酸异丙酯(MI)和丙烯酸(AA)为原料,采用活泼单体滴加的方式,通过水溶液自由基共聚合反应制备了MI/AA二元共聚物(PM-AA)。采用FT-IR对产物的结构进行了表征。通过正交实验和单因素实验对影响聚合反应的因素进行了考察和优化。在n(MI)∶n(AA)=1∶2,聚合温度85℃,AA滴加时间为1.5h,聚合时间2h,引发剂过硫酸铵用量为总单体质量的8%时,MI的转化率为76.17%。     

Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions

Runaway phenomena and thermal explosions can originate during the nitration of salicylic acid by means of a nitric acid/acetic acid mixture when the thermal control is lost, mainly as a result of the formation and thermal decomposition of picric acid. The prediction of the behaviour of this system is thus of great importance in view of possible industrial applications and the need to avoid the occurrence of unwanted dangerous events. During a previous investigation a model was developed to simulate its behaviour when the starting concentration of the substrate is too low, thus, preventing the precipitation of poor soluble intermediates. In this work this model is extended to deal with more concentrated systems even in case of a solid phase separating during the process. To this purpose the previously assessed dependence of the solubility of 3-nitro and 5-nitrosalicylic acids upon temperature and nitric acid concentration is included in the model. It is assumed that when 3-nitro and 5-nitrosalicylic acids are partially suspended in the reacting medium a kinetic regime of "dissolution with reaction" is established; that is, the redissolution of these species is a fast process compared to the successive nitration to give dinitroderivatives. Good results are obtained in the comparison of the experimental data with those calculated both in isoperibolic and adiabatic conditions when the revised model is used.     

Conductometric simultaneous determination of acetic acid, monochloroacetic acid and trichloroacetic acid using orthogonal signal correction-partial least squares

A simultaneous conductometric titration method for determination of mixtures of acetic acid, monochloroacetic acid and trichloroacetic acid based on the multivariate calibration partial least squares is proposed. It is possible to obtain an adjustable model to relate squared concentration values of the mixtures used in the calibration range by conductance. The effect of orthogonal signal correction (OSC) as a preprocessing technique used to remove the information unrelated to the target variables is studied. The calibration model was build using conductometric titrations data of 16 mixtures of three acids. The concentration matrix was designed by a orthogonal design. The root mean squares error of prediction (RMSEP) for acetic acid, monochloroacetic acid and trichloroacetic acid with and without OSC were 0.08, 0.30 and 0.08, and 0.15, 0.40 and 0.18, respectively. The results obtained by OSC-PLS are better than the PLS and this indicate the successful application of the OSC filter as a good preprocessing method in multivariate calibration methods. The proposed procedure allows the simultaneous determination of these acids, in the synthetic mixtures.     

果冻中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸同时检测方法

建立了高效液相色谱法同时测定果冻中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸的检测方法。果冻中的5种添加剂经溶解、定容、过滤后测定。方法:采用C18柱;流动相:乙酸铵(0.02mol/L):甲醇=90∶10;柱温:25℃;波长:230nm;检测器:二极管阵列。样品标准加入回收率为98.7%～100.4%,相对标准偏差(RSD)为0.9%～3.0%。方法简便准确,可运于果冻的常规检测。     

Separation and purification of hyaluronic acid by glucuronic acid imprinted microbeads

The purification of hyaluronic acid (HA) is relatively significant to use in biomedical applications. The structure of HA is formed by the repetitive units of glucuronic acid and N-acetyl glucosamine. In this study, glucuronic acid-imprinted microbeads have been supplied for the purification of HA from cell culture (Streptococcus equi). Histidine-functional monomer, methacryloylamidohistidine (MAH) was chosen as the metal-complexing monomer. The glucuronic acid-imprinted poly(ethyleneglycoldimethacrylate-MAH-Copper(II)) [p(EDMA-MAH-Cu²⁺)] microbeads have been synthesized by typical suspension polymerization procedure. The template glucuronic acid has been removed by employing 5 M methanolic KOH solution. p(EDMA-MAH-Cu²⁺) microbeads have been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) images and swelling studies. Moreover, HA adsorption experiments have been performed in a batch experimental set-up. Purification of HA from cell culture supernatant has been also investigated by determining the hyaluronidase activity using purified HA as substrate. The glucuronic acid imprinted p(EDMA-MAH-Cu²⁺) particles can be used many times with no significant loss in adsorption capacities. Also, the selectivity of prepared molecular imprinted polymers (MIP) has been examined. Results have showed that MIP particles are 19 times more selective for glucuronic acid than N-acetylglucose amine.     

在醇水溶剂中硫酸、油酸共掺杂聚苯胺的研究

在一水醇介质中制备了硫酸、油酸共掺杂的聚苯胺，考察了其电化学行为，并用ＩＲ、ＵＶ－Ｖｉｓ、ＤＳＣ和ＳＥＭ进行了表征。结果显示该聚合物为鳞片状、较高的电导率（２Ｓ·ｃｍ－１）、良好的电化学行为和热稳定性。同时讨论了醇溶剂的影响.