固相水合法重质纯碱生产中几个工艺问题的探讨

潍坊碱厂200kt/a固相水合法重质纯碱生产装置经一年多试车生产和技术攻关,已实现了长周期、连续稳定生产,产品质量达到国外JISK—1201—1950标准。本文就该厂的重灰装置,对固相水合法重质纯碱生产中的几个工艺问题进行了探讨,提出了如何稳定水合机的进碱量;一水碱的水分调节;炉气处理流程以及如何提高重质纯碱的粒度质量等方面的经验和方法。     

浅析固相水合重灰大颗粒的控制

重质纯碱中大颗粒含量高不但影响产品的质量,也影响重灰工序生产的稳定和产能。结合我厂多年的重灰生产经验,对重质纯碱运碱系统进行部分改造,同时注重工艺过程控制,剖析生产过程中导致大颗粒高的具体原因,提出相应处理方法。     

浅谈高海拔地区重质纯碱生产的操作要点

在高海拔低气压条件下重质纯碱生产过程中存在水合时不产生结晶现象,其主要原因是因为低气压条件下轻质纯碱与水结合时,温度难以达到结合所需的温度。从而一水碱生成较难,重质纯碱粒度无法达到要求。通过技术分析:控制Mg2+含量,通过Mg2+的粘度特性来满足生产重质纯碱的要求(Mg2+的控制以不影响产品质量为限)。同时通过对化合水浓度的测定控制,化合水温度的控制以及控制轻质碱杂质含量等技术手段,再加上通过对水合机的机械改造办法使水合机内搅动更剧烈,使碱水混合更均匀,同时严格控制好水合时的温度,以达到生产重质纯碱的理想状态和目的。     

液相水合法制低盐重质纯碱法

本发明为一种液相水合法制低盐重质纯碱法，属于化工领域。本发明的液相水合法制低盐重质纯碱法，是将轻质纯碱和碳酸钠饱和液同时加入到水合机中进行水合反应，经水洗、脱水、煅烧、冷却得成品低盐重质纯碱；由于采用了液相水合法，液体与碱可充分混合，生产出的纯碱粒度均匀。另外在离心脱水时加洗水，     

关于重质纯碱

本文较为系统地阐述了重质纯碱的种类,特性、用途、国内外重灰生产的发展概况,重灰生产方法的介绍,以及重灰生产的能耗和经济效益。     

重质纯碱白度的提高与现有工艺的改进

针对目前天津碱厂重质纯碱产品白度低的问题 ,做了较深入的研究工作 ,发现了由普通纯碱制造重质纯碱过程中白度降低的原因 ,同时指出了目前重质纯碱生产中存在的问题与缺欠 ,并提出了改进意见。经过对现有工艺的改进 ,重灰产品的白度能达到 91%以上。     

新型沸腾煅烧干燥技术在纯碱行业的开发与应用

阐述一种以“新型结构的沸腾干燥床”配套不同的生产工艺生产轻质纯碱和重质纯碱的专利技术。并从设备、工艺、投资、运行稳定性、主要技术经济指标等方面分别与轻灰回转干燥技术和重灰回转干燥技术及国外引进的沸腾流化技术进行对比分析,特别是该技术用于重质纯碱生产的比例将会逐步加大,目前在新建、扩建和搬迁的许多纯碱厂已采用。     

用于重质纯碱生产的外热式煅烧炉传动改造的初步探讨

介绍了重质纯碱的特性、前景、重灰煅烧炉的结构以及改造内容。     

国外重质纯碱生产概况

<正> 重质纯碱(称重灰)的优点是重度大,颗粒大、粉尘少、不易结疤和节省包装运输费用等。虽然生产成本较轻质纯碱(称轻灰)稍高,但它的国际市场价格要比轻灰高约3%(见表1)。它用于炼钢工业和玻璃生产时可以延长反应炉的寿命一年左右,深受用户欢迎,近年来各国都在发展重灰的生产。     

挤压法重质纯碱技术

自贡鸿鹤化工总厂１５０ｋｔ／ａ（２０ｔ／ｈ＿挤压法重质纯碱装置是引进日本细川密克阴集团德国Ｂｅｐｅｘ公司技术建成的我国第一套挤压法重质纯碱装置,也是同等生产规模世界第二套Ｂｅｐｅｘ公司的纯碱挤压装置。介绍自贡鸿鹤化工挤压法重质纯碱的工艺流程、化工单元组合、引进主要设备的工作原理、布置特点、试车及技术改进情况。对以轻质纯碱为原料生产重质纯碱常采用的固相水合法与挤奈中工艺路线简单地进行技术经济比较。可     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.