烟气组分对化学吸收-生物还原法处理NOx的影响

利用经学吸收-生物还原处理烟气中NOx的方法对模拟烟气中O2和CO2影响因子进行了系统的研究.结果表明,50 ℃时,尽管在模拟烟气中O2体积分数从0增加到5%,吸收液的溶解氧浓度升高至0.85 mg/L,造成有效吸收液成分Fe(II)EDTA（EDTA：乙二胺四乙酸）浓度有所下降,但由于生物还原的作用,使得Fe(II)EDTA可以有效再生,系统NO去除效率从95%降低到90%,仍维持在较高的水平;烟气中的CO2能缓冲吸收液的pH值,使pH维持在6.5～7.0,从而有利于脱硝系统的连续运行;对脱硝装置处理负荷的考察证实了O2体积分数的增加会降低系统的生物还原负荷速率.     

基于添加尿素的烧结过程中SO2减排

提出一种基于添加尿素的烧结过程SO2减排技术。将尿素加入烧结混合水中,进行尿素不同配比的烧结杯实验。实验结果表明：尿素受热分解产生的氨气与SO2发生反应,形成的硫酸铵在高温到来之前被抽风带入烧结粉尘并被捕集,实现了与烟气和烧结料层的有效分离。当尿素配比为0.05%（质量分数）时,SO2排放降低52.4%,烧结技术指标影响甚小,且无二次污染产生。     

Effect of sintering atmosphere on composition and properties of NiFe2O4 ceramic

Ni Fe2O4 ceramics were prepared in different sintering atmospheres. The phase compositions, microstructures and mechanical properties were studied. The results show that the stoichiometric compound Ni Fe2O4 cannot be obtained in vacuum or atmospheres with oxygen contents of 2×10-5, 2×10-4 and 2×10-3, respectively. All the samples sintered in above-mentioned atmospheres contain phases of Ni Fe2O4 and Ni O. With increasing oxygen content, Ni Fe2O4 content in the ceramic increases, while Ni O content appears a contrary trend. In vacuum, Ni Fe2O4 ceramic has average grain size of 3.94 μm, and bending strength of85.12 MPa. The changes of the phase composition and mechanical properties of Ni Fe2O4 based cermets are mainly caused by the alteration of their properties of Ni Fe2O4 ceramic.     

Influence of ZrO_2 on sintering and crystallization of CaO-Al_2O_3-SiO_2 glass-ceramics

1INTRODUCTION Nowadays,glassresearchersandarchitecture designersbecomeinterestedinthesinteringglass ceramics,anewlyappearingmaterialforarchitec turaldecoration[13].Comparedwithnaturalstone materials,sinteringglass ceramicsdecoratedmate rialshavethefollowingadvantages:densestruc tureandhighstrength.Itsbasicglasscomponents belongtoCaO Al2O3SiO2system.Becausenonu cleationagentisrequired,thissystemisattributed tothesuperficialcrystallizationmechanismofglass[4].Theproductionprocessofsinteri…     

纳米添加剂在陶瓷烧结中的作用

用微米级和纳米级两种复合助剂Y2O3-Dy2O3加入氮化铝陶瓷(AlN)中,在1650℃热压烧结AlN陶瓷;研究其对AlN陶瓷的微观结构和性能的影响.结果表明:纳米级添加剂Y2O3-Dy2O3能更好地提高AlN陶瓷的烧结活性,热扩散率也更高.     

Influence of sintering temperature on the thermoelectric properties of Ba8Ga16Si30 clathrate treated by spark plasma sintering

A series of Ba8Ga16Si30 clathrate samples were prepared by arc melting, ball milling, acid washing, and spark plasma sintering (SPS). X-ray diffraction analysis revealed that the lattice of the Ba8Ga16...     

物料化学爆炸引起尿塔塔体爆破可能性分析

1995年和2005年,国内发生了两起尿素合成塔(以下简称“尿塔”)塔体严重爆破事故.作者就尿塔内物料发生化学爆炸的多种可能性做了具体分析和计算,并与实际尿塔爆破事故所产生的破坏程度进行了比较.结果表明,如果尿塔未存在严重缺陷,塔内物料发生化学爆炸所产生的能量不足以造成两起事故尿塔塔体的严重爆破和周边环境的巨大破坏.因此,作者认为尿塔塔体爆破的原因是：尿塔塔体存在严重制造缺陷或者是强度层板存在严重应力腐蚀开裂,产生塔体严重破裂引发的物料蒸汽爆炸.     

Fundamental study on iron ore sintering new process of flue gas recirculation together with using biochar as fuel

It is of great significance for cleaner production to substitute bio-energy for fossil fuels in iron ore sintering. However, with the replacement ratio increasing, the consistency of heat front and flame front is broken, and the thermal utilizing efficiency of fuel is reduced, which results in the decrease of yield and tumble index of sinter. Circulating flue gas to sintering bed as biochar replacing 40% coke, CO in flue gas can be reused so as to increase the thermal utilizing efficiency of fuels, and the consistency of two fronts is recovered for the circulating flue gas containing certain CO2, H2 O and lower O2, which contributes to increasing the maximum temperature, extending the high temperature duration time of sintering bed, and results in improving the output and quality of sinter. In the condition of circulating 40% flue gas, the sintering with biomass fuels is strengthened, and the sintering indexes with biomass fuel replacing 40% coke breeze are comparative to those of using coke breeze completely.     

MgO加入量和烧成温度对镁橄榄石材料物相组成和性能的影响

在镁橄榄石细粉中加入不同含量的电熔镁砂,以树酯为结合剂,在不同温度下进行烧成,制备镁橄榄石耐火材料。对烧成制品的物相组成、显气孔率、体积密度和常温耐压强度进行检测,研究不同电熔镁砂含量和烧成温度所制镁橄榄石的物相组成和性能。结果表明,随着镁砂含量的增加,镁橄榄石耐火材料的显气孔率逐渐增大;随着烧成温度的提高,镁橄榄石耐火材料的显气孔率逐步降低,有利于加速其合成。     

冷却预处理器对烧结烟气温度影响仿真研究

由于烧结烟气温度很高,导致脱硫效率下降．漩涡撞击法脱硫设置了冷却预处理器,降低了烟气温度．本文采用Fluent软件对冷却预处理器运行机理进行模拟仿真,并用MATLAB拟合其规律．结果表明：冷却预处理器喷水量越大,烟气温度越低,当喷水速度大于30m／s时,随着喷水量增大,温度变化不明显,最佳喷水速度范围为25～30m／s．     

Influence of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass-ceramics

ZrO2 was added into CaO-Al2O3-SiO2 glass-ceramics and the effect of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass ceramics was investigated. The results show that the sintering shrinkage ratio of glass particles decreases with the increase of the content of ZrO2. ZrO2 has an unfavourable effect on sintering shrinkage ratio of glass particles. The sintering shrinkage ratio of glass particles increases with the increase of sintering temperature. The increase of sintering temperature favors the decrease of the liquid phase viscosity of glass particles. ZrO2 has little effect on crystallization of main crystalline phase （β-wollastonite）. However, it promotes the crystallization at relatively low temperature.     

烧结温度对Ni-Zn铁氧体组织和性能的影响

本文利用传统陶瓷制备工艺制备了Ni-Zn铁氧体材料,用SEM,XRD观察其微观结构,使用Agilent 4294A阻抗分析仪检测样品的磁性能.研究了不同烧结温度对Ni0.4Zn0.6Fe2O4材料的起始磁导率、功耗和显微结构的影响。结果表明,在1 250℃烧结时试样有较好的综合性能,不仅具有较高的磁导率而且损耗也较小。     

生物滴滤法脱除废气中SO2工艺的研究

优化生物滴滤塔的性能,以提高其对SO2废气的处理效率．在单因素实验的基础上,以气体流量、SO2浓度、温度及pH值作为考察因素,通过设计正交试验,研究其脱硫最佳工艺条件;在最佳工况条件下探讨不同入口浓度、不同填料层高度及喷淋量对脱硫效率的影响．结果表明,各因素对SO2去除率影响大小次序为SO2浓度〉温度〉气体流量〉pH值;最佳工艺条件为气体流量0．9m^3／h,SO2浓度1000mg／m^3,pH值2．3～2．4,温度28℃．脱硫率随填料层高度增加而增大,30L／h喷淋量的脱硫效果较优于24L/h,并且生物滴滤法比较适合于低浓度脱硫．     

湿法磷酸合成磷酸脲的工艺研究

目的——研究湿法磷酸合成磷酸脲的工艺.方法——通过正交实验,对反应温度、反应时间、物料比以及母液的循环利用等各影响因素加以分析.结果——确定了湿法磷酸合成磷酸脲的最佳工艺条件为反应温度T=70℃;反应时间t=35min;摩尔比(n(CO(NH2)2)∶n(H3PO4))=1.05∶1.结论——湿法磷酸合成磷酸脲要求磷酸浓度低,生产成本较低,且生产中母液可循环使用,使废料排放降至最低.     

液相催化氧化脱除烟气中SO_2和NO_x机理讨论

对液相催化氧化ＳＯ２和ＮＯｘ进行了较为系统的理论讨论,综述了液相催化氧化吸收ＳＯ２和ＮＯｘ以及过渡金属离子的催化作用,探讨了液相溶液中ＳＯ２和ＮＯｘ同时存在时可能发生的反应,为今后研究ＳＯ２和ＮＯｘ的湿式脱除提供参考。     

二次精还原工艺对铁粉化学成分的影响

研究了二次精还原温度、时间、生粉料层厚度等工艺因素对铁粉化学成分的影响，提出了工业生产高品位铁粉的合理工艺制度。     

Effects of sintering additives on preparation of CaF2 transparent ceramics

The effects of different sintering addictives on the preparation of CaF2 transparent ceramics were studied. Transparent CaF2 ceramics were fabricated by vacuum sintering and hot isostatic pressing (HIP) method, using CaF2 nanopowders synthesized by chemical precipitation method as raw materials. The nanopowders and transparent ceramics were studied using X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and spectrophotometer. The experimental results indicated that the obtained nanopowders presented normal distribution with grain size about 30 nm; transmittance of CaF2 transparent ceramics was 39% and 26% at 1100 nm for LiF and NaF as sintering addictives, respectively, with corresponding mean grain size 188 μm and 44 μm. Loss of transmission could be attributed to the residual closed porosity. Sintering mechanism was liquid-phase sintering at pre-stage, then solid-phase sintering at later stage, as well as solid solution of lithium ions and sodium ions in the CaF2 lattice structure.     

南昌市区二氧化硫污染影响因素分析

通过对南昌区地面风、污染系数、污染源、SO2浓度和各气象因素的关联性及相关性等进行分析，可以得知南昌市东北方向的污染系数大，工业布局不合理对市区的污染影响很大。主导风向及其风速、气压、降水量和2时稳定度是影响南昌市空气SO2浓度的重要因素。各测点SO2浓度与气压、降水量、清晨2时稳定度等的关联度大，但不是简单的线性相关系数。     

SO_2气氛下半焦负载Na,Ca,Fe对NO-半焦还原反应的影响

通过程序升温实验和暂态响应实验 ,研究了 SO2 气氛下半焦负载 Na,Ca,Fe对 NO-半焦还原反应的影响 ;结果表明 SO2 对 NO-半焦反应的影响因温度高低而不同 ,低温下由于 SO2 在半焦表面的化学吸附占据了半焦表面的活性位 ,因而抑制 NO的还原 ,高温则有利于 SO2 - NO气相反应 ,从而致使 NO转化率升高 ;SO2 对 NO-负载催化剂半焦还原反应有抑制作用 ,其抑制程度与温度有关 ,低温下随温度升高 ,抑制程度增加 ,高温下随温度升高抑制程度降低 ;负载 Na,Ca和 Fe的半焦在 SO2 气氛下对 NO-半焦还原反应表现为不同的活性 ,其中 Fe的活性最高 ,Na的活性受 SO2 影响最大 ,这与硫酸盐的分解温度以及 SO2 在半焦表面化学吸附性质有关 .