氯化法钛白生产工艺中四氯化钛氧化微观反应机理研究进展

氯化法是国际上生产高档金红石钛白的主要方法,具有产品质量好、环境污染小、自动化程度高、综合能耗低等优点,在钛白生产领域具有很高的应用价值和发展前景,但对于四氯化钛的氧化反应机理却尚未明确,因此探明四氯化钛氧化反应机理已成为氯化法钛白生产技术的研发重点。本文从表观反应机理、微观反应机理角度论述四氯化钛氧化反应机理研究概况,并对二氧化钛的气相成核、晶核表面生长及三氯化铝的作用机制等研究进展进行分析,展望四氯化钛微观氧化反应机理的研究方向。最后指出,四氯化钛氧化反应机理的研究对氧化反应器的放大设计、产品的形态控制、避免结疤等工业生产具有重要指导意义。     

淀粉粘合剂的反应历程及质量控制

探讨了淀粉粘合剂生产工艺过程及反应历程,指出了传统生产工艺的缺陷,确定了冷法生产工艺中适宜的工艺条件,解决了粘合剂存在的粘接强度低、稳定性差等若干产品质量问题,并在实际应用中获得成功。     

A low-temperature combustion synthesis process for production of Ti from TiO2

Calciothermic reduction of titanium dioxide is suggested as an alternative to the conventional Kroll process for production of metallic titanium. In this study, a simple reactor was used to carry out the reaction of TiO₂ with 20 wt % excess Ca at 1000°C to obtain titanium product with a mean size of Ti particles around 20 μm. A sharp decrease in reaction temperature can be achieved by using KClO₄ as an additive. In this case, sub-micron agglomerated titanium particles were obtained.      

Fe2O3催化无烟煤燃烧燃点降低机理的实验研究

利用TG-DTG法和DTA法研究了无烟煤催化燃烧时燃点的变化情况,结果表明Fe2O3可使无烟煤的燃点降低。基于无烟煤燃点的形成原因和催化热解过程,研究了催化热解过程中热解转化率、热解气组成、半焦表面结构的变化情况,结果表明Fe2O3促进了无烟煤的热解,热解转化率、热解气的组成明显变化,热解气热值增加。催化热解产生的半焦表面形貌粗糙,颗粒细碎,比表面积大。由于热解过程直接影响到点燃过程,因此通过催化热解的研究,可知催化燃烧过程中均相燃烧（热解气燃烧）提供给异相燃烧（半焦燃烧）的热量高于非催化燃烧。同时催化热解所得半焦的吸附氧气能力强,在低温时吸附氧气的速率较快,缩短了达到点燃时所需氧气浓度的时间,进而降低了无烟煤的燃点。     

Fe2O3催化无烟煤燃烧燃点降低机理的实验研究

利用TG-DTG法和DTA法研究了无烟煤催化燃烧时燃点的变化情况,结果表明Fe2O3可使无烟煤的燃点降低。基于无烟煤燃点的形成原因和催化热解过程,研究了催化热解过程中热解转化率、热解气组成、半焦表面结构的变化情况,结果表明Fe2O3促进了无烟煤的热解,热解转化率、热解气的组成明显变化,热解气热值增加。催化热解产生的半焦表面形貌粗糙,颗粒细碎,比表面积大。由于热解过程直接影响到点燃过程,因此通过催化热解的研究,可知催化燃烧过程中均相燃烧（热解气燃烧）提供给异相燃烧（半焦燃烧）的热量高于非催化燃烧。同时催化热解所得半焦的吸附氧气能力强,在低温时吸附氧气的速率较快,缩短了达到点燃时所需氧气浓度的时间,进而降低了无烟煤的燃点。     

氯化氢生产工艺探讨

简介合成法与解吸法生产氯化氢的工艺流程，并对其产品进行了比较，分析了两种生产工艺的特点，并提出改进措施。     

海绵钛的生产及应用

介绍了海绵钛的主要特点、用途、质量及生产方法。     

全钛渣原料硫酸法钛白粉生产工艺环境评价

硫酸法钛白粉生产过程副产的硫酸亚铁和废酸是制约硫酸法钛白粉生产工艺发展的重要因素之一。硫酸法钛白粉生产工艺所用原料有3种：全钛精矿、渣矿混合和全钛渣。对不同原料硫酸法钛白粉生产工艺的环境负荷进行了研究,结果表明：采用全钛渣为原料的硫酸法钛白粉生产工艺既能减少副产物对环境的影响,又能降低酸耗、能耗,是现阶段硫酸法钛白粉生产工艺中环境最优的。     

热分析试验评价节煤剂对煤粉燃烧过程的影响

为探究节煤剂产品特性,本文利用热分析方法讨论了3种节煤剂对煤粉燃烧过程的影响。结果表明,添加不同节煤剂,#1、#2、#3煤样着火点分别降低了9.2 ℃、11.2 ℃和88.9 ℃,并且提高放热效率。燃尽指数表明,节煤剂使#1和#2煤样燃尽性能提高,而#3燃尽性能变差。动力学计算表明,节煤剂能够降低煤粉从着火点到最大燃烧速率阶段的反应活化能,从而提高该燃烧过程的反应速率。     

硫酸法钛白粉生产循环经济模式

针对硫酸法钛白粉生产中“三废”产生量大、处理成本高的问题,提出一种以废酸的资源化利用为核心的循环经济模式。水解工序排出的加（H2SO4）约20％的废酸通过多效真空浓缩为w（H2SO4）约55％的硫酸,用于钛白粉或磷化工装置,浓缩过程析出的一水硫酸亚铁用于生产硫酸,焙烧产生的w（Fe）约65％的烧渣作为钢铁厂炼铁原料。详细讨论了废酸浓缩工艺及工艺参数的选择,以及硫酸亚铁制酸需解决的工程问题。     

三氯氢硅生产工艺的优化

分析三氯氢硅合成工艺、精馏工艺中存在的技术问题并进行了改进,介绍了技改取得的效果,并指出今后技改的方向。     

Schlesinger法合成硼氢化钠工艺条件及优化途径

目前工业化合成硼氢化钠的工艺有Schlesinger法和Bayer法,而Schlesinger法是工业化合成硼氢化钠应用最广的工艺,其关键步骤为氢化钠和硼酸三甲酯的合成。本文一方面从氢化钠的合成、硼酸三甲酯的合成及硼氢化钠的合成3个方面详细论述了Schlesinger法合成工艺进展情况;并指出目前方法存在的问题,如采用油液分散金属钠法合成的氢化钠活性差,制约了氢化钠的应用,硼酸三甲酯工业合成过程中过多使用浓硫酸造成环境严重污染。另一方面对Schlesinger法工艺改进提出了几点设想,如企业全流程合成硼氢化钠可节约外购成本和仓储成本;硼酸三甲酯的合成取代浓硫酸的应用,提纯采用盐析的方法均可以减轻环境污染;硼氢化钠水解过程中采用稀液碱溶液代替淡水,可避免硼氢化钠水解,提高产品收率。     

A CFD model for gas uniform distribution in turbulent flow for the production of titanium pigment in chloride process☆

The fluid dynamic behavior of feeding gas (TiCl4) in an annular channel affects the combination of O2 and TiCl4 in an oxidation reactor, a key piece of equipment in titanium pigment production. The numerical procedure was validated by a 3-dimensional gas flow in the annular channel. Applying the validated model, the flow character-istics of TiCl4 in the oxidation reactor with a tangential inlet were simulated and characterized. The flow distribu-tion with five rectifying rings of different structure was simulated and analyzed. The results showed that the rectifying ring improved the distribution uniformity of the pressure and outlet velocity. Compared to the original case without a rectifying ring, the non-uniformity of the pressure and outlet velocity could be reduced by up to 91%and 69%respectively. The rectifying ring #5, which can be instal ed and adjusted easily, is more effective in realizing even distribution. In addition, instal ation of the rectifying ring effectively reduced the circulating flow in an annular channel as well as the total energy loss.     

AOS生产反应机理描述及相关工艺计算

简述了α-烯基磺酸盐(AOS)的特性,通过对AOS磺化反应机理的分析,就反应过程物料组成及相关控制指标进行了理论计算,提供了一系列理论数据,阐述了AOS生产工艺控制关键点。     

A new reduced reaction mechanism of a surrogate fuel for kerosene

The introduction of detailed chemical reaction mechanisms for aviation fuels into complex multidimensional fluid dynamics problems is not practical at the present time. Simplified reaction mechanisms that have been thoroughly evaluated must be developed to address specific issues arising in realistic combustor configurations. A reduced chemical kinetic mechanism features 210 elemental reactions (including 92 reversible reactions and 26 irreversible reactions) and 50 species for the ignition and combustion of n‐decane was compiled and validated for a wide range of combustion regimes. Validations were performed using experimental measurements on a premixed flame of Jet‐A1, O₂ and N₂, stabilised at 1 atm on a flat‐flame burner, as well as from n‐decane shock‐tube ignition experiments. Numerical calculations were performed using this reduced mechanism and the detailed mechanism respectively for n‐decane surrogate fuel. The calculated values of ignition delay times at pressures of 12, 50 bar and equivalence ratio is 1.0, 2.0, respectively and the main reactants and main products mole fractions agree well with experimental data. The present study shows that this reduced mechanism for the n‐decane surrogate can be employed to predict premixed combustion of kerosene. © 2012 Canadian Society for Chemical Engineering     

羰基合成法生产苯乙酸工艺介绍

介绍了羰基合成法生产苯乙酸的工艺过程和工艺特点 ,生产出的产品符合HGB 344 2 - 6 2和QJ/JD HDD1- 99     

低温燃烧合成复相PSZ陶瓷微粉

用水合硝酸盐作氧化剂、以尿素为燃料,根据推进化学计算原料的配比,进行了复相PSZ超细陶瓷粉的低温燃烧合成,考察了不同点火温度以及不同环境温度的影响,并与硝酸盐直接煅烧分解进行了比较。结果发现,点火温度较高时,则燃烧产物中非晶态物质减少;与硝酸盐直接煅烧相比较,低温燃烧合成可快速得到c-ZrO2晶态微粉：细小的分散开的纳米级颗粒和较粗大的颗粒。     

2,4-二氯过氧化苯甲酰合成新工艺研究

研究了以对甲苯磺酰氯为原料合成2,4-二氯过氧化苯甲酰的新工艺,该工艺对原工艺进行了重大改革,其材料成本仅为原工艺的1/10。     

Spontaneous ignition hazards in stockpiles of cellulosic materials: Criteria for safe storage

The ambient temperature at which ignition is brought about in various sizes, shapes and masses of sieved bagasse pith was investigated on a laboratory scale. ΔT-time and ΔT-position profiles were obtained, and critical temperatures are determined to closer than 0.5 K; this is the highest precision for location of the sub-critical/super-critical margin so far reported for any thermal ignition system. Such quality is a pre-requisite for quantitative extrapolation in order to predict the critical sizes for field stock-piles in normal climatic conditions. Scaling rules based on stationary-state, thermal ignition theory are used and comparisons of the results are made with real piles. The predictions are shown to grossly over-estimate the safe size of stock-piles, and the reasons for this discrepancy are discussed. Distinctions between the reactivity in perfectly dry substrates (as is inevitable at the temperatures prevailing in laboratory experiments) and that of natural, wet piles, and the part played by water are important features. A need for supplementary measurements of heat-release rates at temperatures close to those prevailing in stock-piles is stressed. The results are found to be consistent with similar measurements in woodflour and the conclusions are, therefore, applicable to all cellulosic materials at high temperatures.     

A pinch‐like targeting framework for systematic thermal process intensification

The design of intensified systems remains an “Edisonian” effort, whereby new intensification schemes are the product of creativity rather than the result of applying systematic procedures. Under this motivation, this article presents a novel and systematic approach for identifying targets for thermal process intensification, defined as combining two or more heat sources and sinks present in a process flowsheet, possibly along with a thermal utility stream, in a single intensified device where heat exchange takes place. The targeting problem is formulated as a mixed‐integer linear program. An extensive case study illustrating its application is presented. © 2017 American Institute of Chemical Engineers AIChE J, 64: 877–885, 2018