镁合金无铬化学转化膜的研究进展

镁合金是工业上应用广泛的轻金属材料,化学转化膜处理技术是提高铝合金耐蚀性的方法之一。综述了镁合金无铬化学转化膜处理技术,介绍了磷酸盐、锡酸盐、高锰酸盐、稀土金属盐和植酸处理等化学转化膜的形成机理,对于转化膜的性能进行了评价,展望了镁合金化学转化膜的发展趋势。     

建筑用热镀锌板表面不同镧盐转化膜的制备与性能

分别采用常规镧盐处理液、含有柠檬酸的改进镧盐处理液对建筑用热镀锌板进行化学转化处理,制备了常规镧盐转化膜、改进镧盐转化膜.测试并比较了不同镧盐转化膜的结合力、形貌、成分和耐腐蚀性能.结果表明:常规镧盐转化膜和改进镧盐转化膜都由Zn、La、C和O元素组成,与热镀锌板结合较好,并且都能抑制热镀锌板腐蚀.与常规镧盐转化膜相比...     

镁合金化学转化膜的研究进展

综述了国内外镁合金化学转化膜处理工艺的现状,介绍了铬酸盐、磷酸盐、锡酸盐、钼酸盐、稀土金属盐和植酸盐化学转化膜的研究进展。对以上各种转化膜性能进行了评价,并对比了各种方法的优缺点。最后提出镁合金表面化学转化膜技术未来的发展方向。     

植酸在涂装前处理酸洗工艺中的应用研究

介绍了植酸应用于涂装前处理酸洗中的原理,通过试验探讨了植酸处理液对涂膜耐盐雾和附着力的影响。结果表明:以植酸作为主要成分的化学转化膜处理液,能够形成致密的彩虹色化学转化膜,可有效防止钢铁酸洗后的返锈,增强涂膜的耐盐雾性和附着力。     

镁合金无铬化学转化膜的研究现状及发展趋势

综述了镁合金无铬化学转化膜技术,介绍了磷酸盐,锡酸盐、稀土金属盐、植酸盐、氟锆酸盐、高锰酸盐、钨酸盐、单宁酸盐、钼酸盐化学转化膜等的形成机理并进行了评价,展望了今后镁合金无铬化学转化膜的发展趋势.     

铝合金铈盐转化膜的研究

提出了一种铝合金铈盐化学转化成膜工艺,利用电化学方法研究了铝合金铈盐化学转化膜的成膜过程及耐蚀性能,结果表明,成膜促进剂的加入能有效提高铈盐转化膜的成膜速度,所得转化膜对铝合金的点蚀有较好的抑制作用。     

铝材的化学转化膜工艺探讨

介绍了铝材涂装前处理转化膜的应用,分析比较了不同类型的化学转化膜工艺,详细叙述了转化膜的工艺技术参数及质量控制方法。     

铝型材粉末涂装前处理工艺

本文主要介绍了铝型材喷涂粉末涂料前处理工艺。阐明了工艺过程作用,常见的化学转化膜的成分以及铝型材前处理新技术的发展。并介绍了前处理典型工艺和铬化膜常见弊病处理。     

铝及铝合金无铬化学转化处理的研究进展

本文综述了铝及其合金的无铬化学转化处理工艺,包括波美处理法、稀土盐转化处理法、钛/锆盐转化处理法、钼酸盐转化处理法、有机酸转化处理法、硅烷转化处理法六种方法,并对铝及其合金无铬化学转化工艺的研究方向进行了展望。     

热镀锌层柠檬酸改进型铈盐转化膜工艺

研究了热镀锌层柠檬酸改进型稀土铈盐转化膜工艺,探讨了工艺条件对转化膜耐蚀性的影响。通过正交试验和单因素试验得到柠檬酸改进型稀土铈盐转化膜的最佳工艺为:Ce（NO₃）3·6H₂O25³0g/L,H₂O₂4⁶mL/L,柠檬酸20g/L,处理温度70°C,处理时间10min。经柠檬酸改进后的铈盐转化膜耐蚀性能明显优于常规铈盐转化膜。     

影响黄铜化学转化膜质量的因素

采用碱式酸铜－氨水溶液对黄铜制品进行化学氧化。介绍了氧化工艺参数，前，后处理工序，黄铜基体材料状况等因素对黄铜化学转化膜质量的影响。     

On Complex Processing of the Khovu-Aksy Dumps

Theoretical Foundations of Chemical Engineering - The problem of treatment of the dump of Khovu-Aksy with conversion of arsenic into a storable nontoxic sulfide form was studied. The optimum...     

变形铝合金表面锆基化学转化膜的研究现状

化学转化膜是金属表面主要的处理方法之一，具备良好的附着力和耐蚀性，能为铝合金提供一定的临时防护。传统的六价铬酸盐化学转化膜在日渐严苛的环保压力下已经逐渐淘汰，取而代之的是近几年发展迅猛的三价铬及无铬锆基化学转化膜。铝合金可分为铸造铝合金和变形铝合金，按照所含主要合金元素和热处理状态可分为若干个系列和型号。本文选取几种典型的变形铝合金，综述了不同铝合金微观组织对转化膜成膜过程的影响，化学转化液添加剂、预处理和后处理工艺对转化膜性能的调控及作用机理，以及几种典型商业钝化剂在变形铝合金表面的应用。总结了目前变形铝合金表面锆基化学转化膜仍面临的问题和发展趋势，未来化学转化膜需在满足新型铝合金发展要求的基础上，通过不同有机、无机添加剂以及外场作用对转化膜的成膜均一性、完整性进行调控，以提高转化膜的综合性能。     

Enhancement of biodegradability of industrial wastewaters by chemical oxidation pre‐treatment

Chemical oxidation technologies are often employed for the treatment of complex industrial effluents that are not amenable to conventional biological methods. The role of chemical oxidation depends on the treatment objectives and may vary from partial remediation to complete mineralization. In the case of partial treatment, chemical oxidation aims at the selective removal of the more bioresistant fractions and their conversion to readily biodegradable intermediates that can subsequently be treated biologically. Coupling chemical pre‐oxidation with biological post‐treatment is conceptually beneficial as it can lead to increased overall treatment efficiencies compared with the efficiency of each individual stage. This paper reviews recent developments and highlights some important aspects that need to be addressed when considering such integrated schemes. Copyright © 2004 Society of Chemical Industry     

Low‐temperature photopolymerization and post‐cure characteristics of acrylates

Near‐infrared spectroscopy was used to investigate the post‐cure characteristics of acrylates polymerized from ? 75 °C up to room temperature. The results obtained showed that the double bond conversion increased with increasing initiator concentration. Post‐cure was much more striking for samples cured at lower temperatures. The chemical structure of monomer and photoinitiator had a great effect on the post‐cure process. The greater the functionality, the lower the final double bond conversion and the more distinct the post‐cure effect. Copyright © 2006 Society of Chemical Industry Society of Chemical Industry     

Wet oxidation pre‐treatment of woody yard waste: parameter optimization and enzymatic digestibility for ethanol production

Woody yard waste with high lignin content (22% of dry matter (DM)) was subjected to wet oxidation pre‐treatment for subsequent enzymatic conversion and fermentation. The effects of temperature (185–200 °C), oxygen pressure (3–12 bar) and addition of sodium carbonate (0–3.3 g per 100 g DM biomass) on enzymatic cellulose and hemicellulose (xylan) convertibility were studied. The enzymatic cellulose conversion was highest after wet oxidation for 15 min at 185 °C with addition of 12 bars of oxygen and 3.3 g Na₂CO₃ per 100 g waste. At 25 FPU (filter paper unit) cellulase g^?1 DM added, 58–67% and 80–83% of the cellulose and hemicellulose contained in the waste were converted into monomeric sugars. The cellulose conversion efficiency during a simultaneous saccharification and fermentation (SSF) assay at 10% DM was 79% for the highest enzyme loading (25 FPU g^?1 DM) while 69% conversion efficiency was still reached at 15 FPU g^?1 DM. Total carbohydrate recoveries were high (91–100% for cellulose and 72–100% for hemicellulose) and up to 49% of the original lignin and 79% of the hemicellulose could be solubilized during wet oxidation treatment and converted into carboxylic acids mainly (total carboxylic acids = 3.1–7.4% on DM basis). Copyright © 2004 Society of Chemical Industry     

A practical parametrical characterization of the Fenton and the photo‐Fenton sulfamethazine treatment using semi‐empirical modeling

BACKGROUND: Sulfamethazine (SMT) has received little attention in the water treatment literature. Yet, SMT is among the non‐biodegradable substances increasingly found in aqueous media and affecting both public health and wastewater treatments. For a long time, advanced oxidation processes (AOPs) were studied via pure empirical modeling, although the surface response models resulting from lumped information (TOC, COD, etc.) present limitations regarding extrapolation and optimization. Conversely, detailed first‐principles modeling may not be affordable due to the computational burden and the chemical analysis needs. Thus, a balanced approach may be practical in many cases. RESULTS: Experiments on SMT solutions (500 mL, 50 mg L^?1) were performed under conditions set by an experimental design. A set of replicated degradation time‐profiles (TOC and SMT concentrations) was obtained and a semi‐empirical kinetic model was fitted to these data to determine maximum conversion and kinetic rate. CONCLUSIONS: SMT can be completely degraded from water via photo‐Fenton treatment. Conditions for this treatment were investigated and its outcomes were systematically characterized by a simple kinetic model and two lumped parameters, conversion and kinetic rate. Both, the model and the corresponding parametrical characterization are introduced as a means to discriminate the most efficient treatment conditions in a practical and efficient way. Copyright © 2011 Society of Chemical Industry     

Subtly adjusted active layer self‐assembly process for efficient organic solar cells

The phase separation degree of active layers plays a vital role in enhancing the power conversion efficiency of organic solar cells. Two post treatments were employed to optimize the phase separation degree of active layers by subtly adjusting the self‐assembly process for SMPV1:PC₇₁BM based active layers (SMPV1, 2,6‐bis[2,5‐bis(3‐octylrhodanine)‐(3,3‐dioctyl‐2,2':5,2''‐terthiophene)]‐4,8‐bis((5‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b']dithiophene; PC₇₁BM, [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester). In this work, a power conversion efficiency of 7.93% was obtained for devices with an as‐cast active layer, which is close to the highest values reported for SMPV1 based devices. The power conversion efficiency was further increased to 8.64% or 8.99% for active layers with thermal annealing or thermal annealing together with solvent vapor annealing, respectively. The enhanced performance is mainly attributed to more efficient photon harvesting and charge transport induced by the post annealing treatment of the active layers. The face‐on molecular orientation of SMPV1 is increased for active layers with post annealing treatment, which is beneficial for charge transport along directions perpendicular to the substrate. This work further confirms the positive effect of post annealing treatment on the performance improvement of organic solar cells. © 2019 Society of Chemical Industry     

120kt/a硫铁矿制酸装置试运行总结

宁夏兴尔泰集团中宁兴德化工有限公司120 kt/a硫铁矿制酸装置采用沸腾焙烧、废热锅炉、电除尘器、文—填—电酸洗净化、"3+2"二转二吸流程。装置竣工到正式开车时隔2年,不少设备和管道都进行了更换和维修。开车正常近一年来装置开工率为96%以上,烧出率99.28%,做到了出磁性渣、提高了矿渣的利用价值,蒸汽产量达到1.1 t/t,转化率达到99.72%,吸收率99.99%,尾气及污水经处理后达标排放。     

铁钼法甲醛工艺中甲醇转化率低的原因及改进

介绍了河南开祥化工有限公司引进美国DBW铁钼氧化法生产甲醛的工艺,从空气质量、催化剂、氧含量、空速、反应温度、吸收水pH、甲醇雾化率等方面,分析了甲醛生产过程中甲醇转化率低的原因,并总结了实际生产中提高甲醇转化率的方法:控制工艺操作参数、保证催化剂装填质量、注意催化剂的保护等。