Selective removal of heavy metal ions from aqueous solutions with surface functionalized silica nanoparticles by different functional groups

The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as（3-Mercaptopropyl） triethoxysilane（MPTES） and（3-Amincpropyl） trithoxysilane（APTES）. Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared（FI-IR） and X-ray photoelectron spectroscopy（XPS）. The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2＋, Cu2＋, Hg2＋, Cd2＋ and Zn2＋ions in aqueous solutions. The results show that the（3-Mercaptopropyl） triethoxysilane functionalized silica nanoparticles（SiO2-MPTES） play an important role in the selective adsorption of Cu2＋ and Hg2＋, the（3-Amincpropyl） trithoxysilane（APTES） functionalized silica nanoparticles（SiO2-APTES） exhibited maximum removal efficiency towards Pb2＋ and Hg2＋, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2＋ at room temperature, respectively.     

Mechanism of Fume Suppression and Performance on Asphalt of Expanded Graphite for Pavement under High Temperature Condition

Fume suppression mechanisms and the effect of expanded graphite on the performance of asphalt were studied by applying infrared spectroscopy(FT-IR), X-ray diffraction(XRD), scanning electron microscopy(SEM) and comprehensive thermal analysis(TG, DSC). The experimental results confirm that asphalt which is mixed with expandable graphite will expand in the process of hot mix, and the expanded graphite layer will swell by the light component in the asphalt. The light component in the asphalt and PAHs adsorption on expanded graphite surface or part of the plug in the expanded graphite layer between plates made nucleation crystallization growth. And the Van der Waals force and the bonding of the lattice can effectively restrain the asphalt fume release. Meanwhile, the expanding agent with oxidative can spread into the asphalt, leading to asphalt oxygenated and plastic abate, while the ductility decreases. Expanded graphite, SBS modifier and environment- friendly plasticizers are used to composite modified asphalt. According to asphalt fume release experiment, normal test of asphalt performance, Brookfield viscosity test, RTFOT test and asphalt mixture tests(high temperature stability, low temperature stability, water stability), it has been proven that the modified asphalt's performance is better than that of matrix asphalt and equivalent to that of SBS modified asphalt. Furthermore, it has good fume suppression effect.     

焦炉煤气组合脱硫工艺的讨论和比选

介绍了真空碳酸盐法（VS法）、氨硫联合洗涤法（AS法）、ADA法焦炉煤气脱硫工艺的优缺点,并对VS-WSA工艺、ADA-硫磺工艺、AS-WSA工艺与AS-硫磺工艺的经济效益进行了比较,为选择科学可靠的焦炉煤气脱硫工艺提供了参考.     

华兴化工超重力氨法脱硫及硫酸盐系列产品生产实践

介绍了华兴化工200 kt/a硫铁矿制酸装置尾气超重力脱硫工艺流程和生产实践情况。硫酸二系列尾吸系统采用超重力技术改造后已稳定运行2个多月时间,超重力反应器氨法脱硫后的尾气ρ（SO2）240～680 mg/m3,达到预期改造目的。脱硫副产亚硫酸铵和亚硫酸氢铵含量约400 g/L的亚盐溶液7 kt/a左右,用于液体二氧化硫、焦亚硫酸钠、硫酸铵、过硫酸铵、过硫酸钠、亚硫酸钠等硫酸盐系列产品生产。在减少SO2污染的同时,华兴化工进一步拓宽了硫化工产品链。     

地下矿山上山(天井)安全施工的实践

对地下矿山上山(天井)施工过程中存在的不安全因素进行了分析,同时提出了一系列简单、有效、可行的施工措施,较好地解决了上山(天井)施工难、险的问题,确保天井施工的安全。     

亚硫酸镁清液法脱硫技术在金隆环集烟气处理中的应用

介绍了金隆铜业环集烟气脱硫装置所使用的亚硫酸镁清液法脱硫技术,该技术具有投资省,能耗低,运行成本低,占地面积适中等特点,并能根据实际情况合理分块布局。该技术的应用为行业大烟气量脱硫开辟了新的途径。     

活性炭脱硫富集烟气制酸系统技术改造实践

介绍了新450m^2烧结机烟气活性炭脱硫富集烟气制酸系统流程和存在问题。针对喷淋塔进口烟气温度偏低、泡沫柱高度不足、干燥塔进口尘含量超高、分酸槽内酸泥堆积严重、成品酸色度差等问题采取有效改造措施。改造后系统运行正常,产品酸清澈透明。     

Estimation of Sorption Isotherms for Dry Desulphurization of Flue Gas in a Fluidized Bed Reactor

A model approach is presented here to obtain sorption isotherms that are connected with a low cost breakthrough analysis for dry desulphurization of flue gas in a fluidized bed reactor. Experiments were conducted at different temperatures (600–900°C) providing constant feedstock concentration (0.6% SO₂). The fluidizing gas entered the bed through a distributor and fluidized the single charge of 15 g sorbent. The space velocity ranged from 3100 to 5700 h^?1. Each run was terminated when the steady state was reached. Sulfate layer thickness was calculated from conversion ratio and the structural parameter. Inserting this value and the particle size parameter into the mass transfer equation then extracted the process parameters. Equilibrium relationships involving these parameters were compared with different isotherms. The agreement between the experimental and predicted values of the sorption isotherms validated the model. The latter may be successfully used to design reactors for e.g., sulfating or desulphurization.     

石灰石-石膏湿法脱硫技术问题探讨

石灰石-石膏湿法脱硫技术存在着堵塞、结垢等问题,从而降低了脱硫效率。分析了该技术在实际使用过程中存在的问题,并提出相应对策。