硝酸镁法稀硝酸提浓制取浓硝酸

前言浓硝酸是化工、医药、国防、染料和纺织工业的重要原料。工业上生产浓硝酸有直接法和间接法两种。直接法是在一定的温度和压力下用液态氮氧化物、氧气和水直接合成浓硝酸。间接法是先制成稀硝酸,再将稀硝酸在脱水剂存在下蒸馏制得浓硝酸。稀硝酸是一种具有最高恒沸点的水溶液,其最高恒沸点为121.9℃,相应的硝酸浓度为68.4%。欲将稀硝酸直接蒸馏得到浓硝酸是不可能的,只有在脱水剂作用下才能使稀硝酸脱水     

增设稀甲醛提浓塔

在生产1，4-丁二醇工艺中，增加稀甲醛提浓塔，可以解决原料甲醛浓度偏低，回收的稀甲酵量增多时，无法全部用于甲醛配制而制约产量的矛盾。     

洗涤方法再探讨

用浓浸稀洗法洗衣服较一般方法好,对同一衣物用同量的洗衣液有较好的去污力,或达到同一去污效果用少量洗衣液即可.在洗衣液中采用价廉,不耐硬水的表面活性剂将进一步降低洗衣液的生产成本,而且节能.     

提高综合法硝酸生产装置的浓稀比

介绍综合法硝酸装置生产情况,通过对该装置浓稀比的现状分析,找出浓稀比偏低的主要原因。采取一系列优化措施,解决了生产难题,使装置浓稀比达到行业领先水平。     

应用稀氨水逐级增浓技术回收氨

本文论述了采用稀氨水逐级增浓技术,取得了明显的经济效益和环境效益。该技术的关键在于“一点加水”和“等压吸收”,使该厂省去了回收塔、硬水清洗塔、水泵等设备。氨回收率由64%提高到90.3%,由亏氨变成了盈氨,年经济效益达36万元,当年可回收投资。     

铜与浓稀硝酸反应的微型化实验设计

铜与浓稀硝酸的反应以及一氧化氮、二氧化氮的性质实验室中学化学重要实验,在中学化学中,硝酸、一氧化氮、二氧化氮的性质是通过几个独立的实验分别研究的,在实验过程中,会多次对环境造成污染,也会对实验人员观察者造成伤害,同时也无法演示NO转化为NO2的过程.分开做实验也容易造成药品浪费.     

稀硝酸──浓硝酸联合生产方法介绍

控制浓硝酸生产中产生酸水的氯根含量，将其酸水返回稀硝作为吸收用水，构成稀硝─浓硝联合生产法，可获得可观的经济效益和社会效益。     

以稀磷酸代替浓磷酸生产硫基氮磷钾实践

介绍了云南云天化股份有限公司云峰分公司100 kt/a复合肥装置工艺流程。为解决云峰公司磷酸产能不足问题,采用磷酸中间产品稀磷酸生产氮磷钾产品,通过优化工艺操作,控制好系统水平衡和热平衡,减缓系统设备及管线结疤,提高了装置运行率。生产中装置产能提高近33%,节约磷酸浓缩蒸汽81～105 kg/t。     

稀氨水提浓节能技术在中加清洁生产示范中的应用

介绍了稀氨水提浓节能技术 ,节能与环保并举 ,为小化肥生产解决了一道难题。     

磷酸二铵洗涤系统浓磷酸更改为稀磷酸的可行性分析

为减少磷酸二铵洗涤系统浓磷酸消耗量及工艺水消耗量,对生产系统水分和五氧化二磷进行物料衡算。得出将洗涤工序部分浓磷酸更改为稀磷酸是可行的,不仅可减少结垢及降低浓磷酸的消耗量,而且可减少生产中工艺水的消耗量。     

Effects of soaking soybeans in dilute acids on biologically active components

Soaking soybeans in dilute acids affected activities of lipoxygenase, trypsin inhibitor and urease. Effects of soaking time, acid concentration and soaking temperature were investigated. Lipoxygenase activity was completely eliminated by soaking in 0.3 M HC1 at either 23°C or 40°C for 8 hr. Less than 50% trypsin inhibitor remained and urease was inactivated to an acceptable level (0.04 ΔpH).     

Diffusion in dilute polytetrahydrofuran solution

The diffusion coefficients of four polymer-solvent mixtures at 34.0‡C were measured using a Mach-Zehnder diffusiometer. Monodisperse (M_w/M_n <1.05) polytetrahydrofuran (PTHF) with and without OH-end group were chosen for this work to study the effects of association of polymer molecules on the diffusion coefficient. In order to minimize the interaction between solvent and polymer molecules, bromobenzene having no hydrogen bond-forming capability was employed as a solvent. The experimental results showed that the OH end group indeed affected diffusion property of dilute polymer solution. An association model was developed in this work and the experimental results were interpreted based on the model.     

The characterization of acetylated commercial polyvinylbutyral in dilute solution

Single organic solvents have been found in which commerical polyvinylbutyral does not aggregate after acetylation, and can therefore be characterized from the molecular standpoint by using classical absolute methods (light scattering and membrane osmometry). In addition, this possibility is also demonstrated by means of size exclusion chromatography with both the styragel and silicagel column packings.     

高浓度洗煤废水处理技术与工程实践

研究分析了晓明矿洗煤废水的性质及难处理的原因,并针对晓明矿洗煤废水难以自然沉降的难题,研究开发出采用电石渣和PAM处理洗煤废水的实用技术,介绍了该项技术的实际应用情况。     

聚氯乙烯树脂稀溶液黏度测定方法的研究

研究了聚氯乙烯树脂稀溶液黏度的测定方法,通过试验确定了方法的操作条件,并验证了方法的可行性。     

The structure of linear polyethylene crystals formed in dilute solution

Summary Raman LAM and internal mode studies have been made on crystals of linear polyethylene formed in dilute solution. The molecular weight range, 5×10⁴–1.5×10⁶, was much greater than has been studied heretofore. The crystallite core thickness and degree of crystallinity was found to be independent of molecular weight for a given crystallization mode. The internal mode analysis indicates a substantial disordered overlayer, which is primarily isotropic in character.     

The electrochemical hypochlorination of allyl chloride in dilute HCl solution

The electrochemical hypochlorination of allyl chloride has been studied. It was found that the reaction is best effected using 1 to 1.5 N HCl as the electrolyte, introducing allyl chloride as an emulsion and working at low current density (< 150 mA cm^–2).     

盐酸体系汽液平衡及稀盐酸处理方法的研究进展

国内化工及相关行业每年产生数千万吨稀盐酸需要处理并循环使用,因此,稀盐酸处理方法的研究近年来一直受到高度的重视。盐酸体系的汽液平衡及其盐效应下的汽液平衡对于研究稀盐酸处理方法具有重要意义。文中总结了HCl-H_2O二元体系、HCl-H_2O-盐三元体系的汽液平衡以及汽液平衡数据的关联计算。阐述了常规解吸法、压差法、萃取精馏法、组合法和多效膜蒸馏过程等稀盐酸处理方法的研究现状和进展。针对目前稀盐酸处理方法,提出了基于组合法处理稀盐酸的新方法,对研究废稀盐酸处理方法具有一定的指导意义。