流化状态下附碳赤铁矿粉物质形态的研究

对流化状态下赤铁矿粉附碳后的物相组成、显微结构、化学组成及矿粉被还原程度进行研究。通过矿相分析、电子显微镜分析、X射线衍射分析、穆斯堡尔谱学分析 ,发现流化状态下的赤铁矿粉随附碳时间的延长 ,颗粒结构变得疏松多孔 ,还原程度加深 ,颗粒表面形成的金属铁很少 ,有利于防止粘结。

熔融还原流态化预还原中铁精矿粉附碳处理的最佳化

附碳处理是一种最新开发的强化流态化还原过程的新技术,本文对铁精矿粉附碳处理的最佳化进行了研究。找出了附碳处理的最佳工艺参数,并指出确定最佳参数的依据,这对附碳处理工艺在流态化预还原中的工业应用具有重要的价值。

二步熔融还原中附碳处理加速流态化预还原过程机理研究

本文从还原模型、固态结构和形态学的角度对“二步熔融还原”中流态化预还原附碳精矿粉的还原机理进行了讨论,提出了附碳精矿粉的“裂化——催化”还原机理,并确定了一种工业上可行的加速还原反应速度的方法,这种方法还能解决流态化还原中常见的粘结现象。采用这种方法可使预还原时间(达到70%还原度)缩短到5分钟,仅为原来的1/3。

熔融还原中流态化预还原料附碳处理的防粘作用

本文对附碳处理的防粘结作用进行了研究,找出了附碳量与粘结指数的关系,以及附碳处理防止粘结的原因。结果表明,附碳处理对粘结的防止相当有效,只需少量附碳(1%～2%)就足以满足防粘结要求。

铁矿粉流态化附碳与还原过程的研究

在内径φ27mm的石英流化床中对铁矿粉进行低温附碳和高温还原的实验,通过对附碳矿粉及其还原样品的物检分析,不仅对矿粉还原过程中的形貌和成分的变化有了深刻的认识,进一步了解了还原反应进行的形式及内部结构的变化,以及所得附碳矿粉还原防粘的机理,为以后的扩大实验提供了依据。

铁矿微粉低温输送预还原及附碳行为

研究了铁矿微粉低温输送预还原中气固比、还原时间、炉温、矿粉粒径、还原剂种类等参数对矿粉还原率的影响,并运用正交设计和模式识别方法对工艺参数进行了优化,对预还原过程中样品的附碳行为进行了探讨.结果表明,在矿粉粒径14～20μm、炉温660～700℃、反应时间180～220s、还原气成分CO0～20%()的优化条件下,预还原率较高,最高达70.16%.XRD分析表明,还原样品发生碳吸附现象,少量氢气可提高碳吸附率.

经附碳处理的赤铁精矿粉在熔融还原、流态化预还原过程中的附碳（CA）效应

本文通过对经附碳处理的赤铁精矿粉在预还原时附碳（ＣＡ）效应的研究，提出了附碳的温度效应、催化效应及物理效应．分析了压力对各种效应的影响，并探讨了这些效应的机理．

熔融还原中流态化附碳过程的研究

本文通过对多种原料附碳后的矿相结构研究，分析了附碳过程的特性，找出了附碳中综合最佳参数，并探讨了附碳机理．

熔融还原流态化预还原赤铁精矿粉附碳还原综合动力学研究

本文通过对赤铁精矿粉流态化预还原试验，探讨了矿粉附碳中与附碳后的还原综合动力学问题，并建立了相应的宏观速率方程和动力学模型，为流态化预还原工艺提供了重要的操作依据．

经附碳处理的澳矿粉在熔融还原流态化预还原过程中的动力学特征

本文通过对附碳澳矿粉预还原实验的研究，建立了还原反应的宏观速率方程，分析了反应的动力学机理．根据实验结果的回归分析，说明了影响还原度的主要因素及其影响程度的大小，并对附碳３．０％的预还原产物建立了温度效应公式和动力学模型．

基于国六法规的碳罐脱附流量对蒸发排放性能的影响

国内整车排放不断加严,对燃油系统的开发带来了极大的挑战。为了应对国Ⅵ法规对蒸发排放性能的要求,文章以某一车型蒸发排放试验超过限值为引入点,详细分析了影响蒸发排放性能的各个因素,总结出在开发过程中控制蒸发排放性能的方法。

Determination of trace amount of antimony (Ⅲ) by adsorption voltammetry on carbon paste electrode

A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: preconcentration,reduction and stripping. Optimal conditions were found to be an electrode containing 25% paraffin oil and 75% high purity graphite powder as working electrode;a 0.10 mol/L HCl solution containing 40 μmol/L BPR as accumulation medium;a 0.20 mol/L HCl solution as reduction and stripping electrolyte;accumulation time,150 s;reduction potential and time,-0.50 V,60 s;scan range from -0.50 to 0.20 V. Interferences by other ions were studied as well. The detection limit was found to be 0.5 nmol/L for 150 s preconcentration. The linear range was from 1.0 nmol/L to 0.50 μmol/L. Application of the proposed method to the determination of antimony in water and human hair samples gave good results.

熔融还原中流态化CA过程动力学

本文对赤铁精矿粉的ＣＡ过程动力学进行了研究，得出了不同温度、压力、线速及成份变化条件下的附碳模型，指出了时间是影响附碳量的主要因素．为其它矿种附碳的反应动力学提供了可行的研究方向．

Synthesis of poly(m-phenylenediamine) with improved properties and superior prospect for Cr(VI) removal

Chemically oxidative polymerization of m-phenylenediamine was improved through adding the weak alkaline, Na2CO3. Results show that the poly （m-phenylenediamine） （PmPD） possesses a weak solubility in acidic solution according to total organic carbon （TOC） that the TOC is less than 8 mg/L, which is much lower than the discharge standard （20 mg/L）. The TOC of the PmPD synthesized with NaOH can be as high as 120.9 mg/L. This very weak solubility of PmPD synthesized with Na2CO3 facilitates its application in water purification. The oxidation state of PmPD is decreased and the yield is increased with a maximum of 84%, promoting the concentration of Na2CO3 in the synthesis. Moreover, the Cr（VI） performance of PmPD was marvelously enhanced with Na2CO3 to improve the synthesis. The largest Cr（VI） adsorbance can reach as high as 666.8 mg/g, which is far more than the performance of other common adsorbents.

Determination of the Real Surface Area of Palladium Electrode

Four methods, including voltammetric measurement of double layer capacitance, surface oxides reduction, under potential deposition of Cu and carbon monoxide （CO） stripping have been applied to evaluate the real surface area of a polycrystalline Pd （pc-Pd） electrode. The results reveal that the second and third methods lead to consistent results with deviations below 5%. And from the determined double layer capacitance and CO stripping charge, it is deduced that the double layer capacity unit area is 23.1±0.4μF/cm2 and the saturated CO adlayer should be ca. 0.66 ML in order to ensure that the real surface area as determined is consistent with the other two techniques. The applicability as well as the attentions when applying these techniques for the determination of the real surface area of pc-Pd electrodes have been discussed.

Date palm kernel-based GAC and its dynamic modeling of residual chlorine breakthrough curve in multimedia filter

First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activation. Secondly, the ability of the produced GAC to remove pollutants is examined through batch experiments of residual chlorine adsorption whereas the equilibrium isotherm experimental data are tested for the Langmuir and Freundlich isotherms equations. Thirdly, the experimental and theoretical study of dynamic adsorption process and the effect of major operating parameters on dynamic adsorption are investigated. The results show that the Langmuir isotherm gives the best fitting to experimental data, which indicates that the residual chlorine adsorption can be characterized by mono layer adsorption behavior. The produced GAC has a great potential as an adsorbent for residual chlorine in water systems and it can compete favorably with the conventional adsorbents. The Thomas extended model with combined mass transfer resistances is used for verifying the experimental results and the results show that the proposed model coincides well with the experimental data of the dynamic adsorption process.

Modelling of adsorption of textile dyes over multi-walled carbon nanotubes:Equilibrium and kinetic

The paper deals with the application of multiwall carbon nanotubes(CNTs) to the adsorption of dyes from wastewater. Textile dyes are dangerous and diffused pollutant in wastewater, and the paper results confirmed the good adsorption ability of CNTs, with respect to classic active carbon, even for different dye types. The effect of surface treatments of CNTs was primarily investigated, revealing that neither the presence of residual catalyst nor common surface treatment(oxidation) affects the CNT's performances. Therefore less expensive nonpurified CNTs were assessed as good and economically convenient alternative for the process. In order to gain in generality in adsorption kinetic modelling, the parameters of the "best fitting" pseudo-second order model have been correlated to the main process variables(the dye initial concentration and the specific mass of CNTs.) setting-up a predictive kinetic model useful design new application of these materials in currently operating industrial operations for adsorption. In addition, isothermal data were used to screen all the relevant adsorption isotherms models and the Temkin model was confirmed as the more effective to accurately fit equilibrium data for any of the considered different dye types.

Influence of Carbon Content on S Zorb Sorbent Activity

The reaction activity of S Zorb sorbents with different sulfur contents was investigated, and the structure and composition of carbon-containing sorbents were characterized by XRD, FT-IR and TG-MS in order to delve into the kind and morphology of carbon on the sorbent. Test results have revealed that coke could be deposited on the S Zorb sorbent during the operating process, and the coke content was an important factor influencing the reaction performance of the S Zorb sorbent. Retention of a definite amount of coke on the sorbent while securing the desulfurization activity of the S Zorb sorbent would be conducive to the reduction of octane loss of reaction product.

Review on porous nanomaterials for adsorption and photocatalytic conversion of CO_2

Photocatalytic conversion of“greenhouse gas”CO2is considered to be one of the most effective ways to alleviate current energy and environmental problems without additional energy consumption and pollutant emission.The performance of many traditional semiconductor photocatalysts is not efficient enough to satisfy the requirements of practical applications because of their limited specific surface area and low CO2adsorption capacity.Therefore,the exploration of photocatalysts with high CO2uptake is significant in the field of CO2conversion.Recently the porous materials appeared to be a kind of superior candidate for enriching the CO2molecules on the surface of photocatalysts for catalytic conversion.This paper first summarizes the advances in the development of nanoporous adsorbents for CO2capture.Three main classes of porous materials are considered:inorganic porous materials,metal organic frameworks,and microporous organic polymers.Based on systematic research on CO2uptake,we then highlight the recent progress in these porous‐material‐based photocatalysts for CO2conversion.Benefiting from the improved CO2uptake capacity,the porous‐material‐based photocatalysts exhibited remarkably enhanced efficiency in the reduction of CO2to chemical fuels,such as CO,CH4,and CH3OH.Based on reported recent achievements,we predict a trend of development in multifunctional materials with both high adsorption capability and photocatalytic performance for CO2utilization.

Modification of CaO-based sorbents prepared from calcium acetate for CO_2 capture at high temperature

CaO-based sorbent is considered to be a promising candidate for capturing CO_2 at high temperature. However,the adsorption capacity of CaO decreases sharply with the increase of the carbonation/calcination cycles. In this study, CaO was derived from calcium acetate(CaAc_2), which was doped with different elements(Mg, Al,Ce, Zr and La) to improve the cyclic stability. The carbonation conversion and cyclic stability of sorbents were tested by thermogravimetric analyzer(TGA). The sorbents were characterized by N_2 isothermal adsorption measurements, scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results showed that the cyclic stabilities of all modified sorbents were improved by doping elements, while the carbonation conversions of sorbents in the 1st cycle were not increased by doping different elements. After 22 cycles, the cyclic stabilities of CaO–Al, CaO–Ce and CaO–La were above 96.2%. After 110 cycles, the cyclic stability of CaO–Al was still as high as 87.1%. Furthermore, the carbonation conversion was closely related to the critical time and specific surface area.