电解法降解刚果红染料废水的研究

应用自制电化学反应器对刚果红染料废水进行电解降解。研究了电解时间、废水pH值、电压、溶液初始浓度等对刚果红电解去除效果的影响,确定了最佳的降解条件：电压5V,电解质硫酸钠加入量15m∥L,电解时间4h。刚果红降解率达到74．1％。     

The calculations of dispersion coefficients inside two‐dimensional randomly packed beds of circular particles

The longitudinal (D_L) and transverse (D_T) dispersion coefficients in two‐dimensional (2‐D) randomly packed beds of circular particles in a laminar flow regime are derived. A 2‐D discrete system of particles is divided into cells using modified Voronoi diagrams. The relationship between the variation of the stream function and the averaged vorticity is obtained from computational fluid dynamics (CFD) simulations. The whole flow pattern is then obtained by using the principle of energy dissipation rate minimization. The obtained values of D_L agree well with 3‐D experimental data for all velocities investigated. At very high velocities, D_T in 2‐D appears to be higher than 3‐D experimental data. In addition, the effects of particle‐size distributions, packing structure, and porosity on the D_L and D_T were studied. One result was that an increase in the width of the particle‐size distribution resulted in higher values of D_L and D_T at high velocities. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1002–1011, 2013     

用梅山硫酸渣生产氧化铁红的试验研究

为提高梅山铁矿硫酸渣的附加值,进行了以该硫酸渣为原料,用选矿方法生产氧化铁红的试验研究。试验采用筛分分级-筛下预磨-漂洗-超细磨-碳硫钙镁反浮选-硅反浮选工艺,获得了Fe₂O₃含量达98.19%,SiO₂含量为0.48%的磁材级氧化铁红和Fe₂O₃含量为95.06%,SiO₂含量为0.83%的颜料级氧化铁红,而筛分筛上产品和反浮选泡沫产品可直接作为铁精矿。     

郑州巩义红黏土的工艺性能研究

以郑州巩义天然红黏土为研究对象,利用X射线衍射分析、x荧光光谱分析和激光粒度仪研究了黏土的矿物组成、化学组成和颗粒组成;利用综合热分析仪研究了黏土加热过程的变化;通过不同煅烧温度点黏土的气孔率和收缩率的变化研究黏土的烧成收缩、烧结温度和烧结范围;同时也研究了黏土的可塑性、结合性、触变性及干燥性能等.实验结果表明:该天然红黏土矿物属于高硅铁黏土矿物.不同矿点成分波动不大,主要由伊利石、石英及赤铁矿组成.具有制作建筑陶瓷材料的工艺性能,适合于建筑材料方面的应用.     

钠钙粉作为添加剂制备赤泥激发偏高岭土胶凝材料

采用XRD、IR、SEM、和EDS等分析手段.研究了钠钙粉作为添加剂制备的赤泥偏高岭土胶凝材料的力学性能和水化产物.结果表明:钠水玻璃模数为1.0、水灰比为0.34、钠钙粉加入量为6%时效果最好,同时得知偏高岭土经强碱激发后的水化产物为C-S-H凝胶和硅铝酸钙.随着试样养护龄期的增长肢凝材料结构更密实,形成PSS型结构.     

Experiments on chemical looping combustion of coal with a NiO based oxygen carrier

A chemical looping combustion process for coal using interconnected fluidized beds with inherent separation of CO₂ is proposed in this paper. The configuration comprises a high velocity fluidized bed as an air reactor, a cyclone, and a spout-fluid bed as a fuel reactor. The high velocity fluidized bed is directly connected to the spout-fluid bed through the cyclone. Gas composition of both fuel reactor and air reactor, carbon content of fly ash in the fuel reactor, carbon conversion efficiency and CO₂ capture efficiency were investigated experimentally. The results showed that coal gasification was the main factor which controlled the contents of CO and CH₄ concentrations in the flue gas of the fuel reactor, carbon conversion efficiency in the process of chemical looping combustion of coal with NiO-based oxygen carrier in the interconnected fluidized beds. Carbon conversion efficiency reached only 92.8% even when the fuel reactor temperature was high up to 970 °C. There was an inherent carbon loss in the process of chemical looping combustion of coal in the interconnected fluidized beds. The inherent carbon loss was due to an easy elutriation of fine char particles from the freeboard of the spout-fluid bed, which was inevitable in this kind of fluidized bed reactor. Further improvement of carbon conversion efficiency could be achieved by means of a circulation of fine particles elutriation into the spout-fluid bed or the high velocity fluidized bed. CO₂ capture efficiency reached to its equilibrium of 80% at the fuel reactor temperature of 960 °C. The inherent loss of CO₂ capture efficiency was due to bypassing of gases from the fuel reactor to the air reactor, and the product of residual char burnt with air in the air reactor. Further experiments should be performed for a relatively long-time period to investigate the effects of ash and sulfur in coal on the reactivity of nickel-based oxygen carrier in the continuous CLC reactor.     

拜耳法赤泥中铁的提取及残渣制备建材

以拜耳法赤泥为原料,经直接还原焙烧-磁选回收铁,磁选残渣用于生产建筑材料。该赤泥中的氧化铁含量27.93%,并以赤（褐）铁矿为主要存在状态。在探讨了焙烧温度、焙烧时间、炭粉及添加剂用量等因素对实验结果影响的基础上,得出较理想的焙烧条件。在该条件下,经磨细磁选后所得精矿中,总铁含量89.05%,金属化率96.98%,回收率81.40%,可用作海绵铁。磁选残渣掺入消石灰经压力成形、蒸汽养护,试件抗压强度可以达到24.10 MPa,可用于生产蒸养砖等建材。残渣在蒸养前后主要矿物组成由霞石转化为钙铝黄长石,热力学分析证明了在实验条件下该反应发生的可能性。     

MRP/MH/EG协同阻燃HDPE的性能研究

以微胶囊化红磷(MRP)、氢氧化镁(MH)及可膨胀石墨(EG)为阻燃剂,采用熔融挤出法制备了多组高密度聚乙烯(PE-HD)阻燃复合材料。采用氧指数测试、垂直燃烧测试、红外光谱分析、激光拉曼光谱分析、热重-差热分析、扫描电子显微镜分析及拉伸性能测试等方法对复合材料的阻燃性能、热稳定性、力学性能和断面的微观形貌进行了研究,并探讨了阻燃机理。结果表明,单独使用EG时阻燃效果差,但将EG与MRP、MH复配使用能有效改善材料的阻燃性能;当PE-HD/MH /MRP /EG = 100/35/15/5(质量份,下同)时,复合材料的氧指数为28.5 %,垂直燃烧达到UL 94 V-0级,而阻燃剂的加入对材料拉伸性能的影响并不是很大;SEM分析表明, EG与PE-HD基材有很好的相容性,而MRP或MH与PE-HD基材的相容性较差。     

白光LED用钼酸盐体系红色荧光粉的研究进展

详细介绍目前白光LED用钼酸盐体系红色荧光粉的研究现状,重点介绍近几年来钼酸盐荧光粉在制备合成方面的最新进展,最后展望了LED用钼酸盐红色荧光粉的发展前景.     

复合热活化对赤泥-煤矸石胶凝性能的影响

研究了600 ℃简单热活化和复合热活化对赤泥-煤矸石胶凝性能的影响,借助ICP、XRD、SEM等微观测试手段对两种活化方式下的赤泥-煤矸石体系的硅铝离子的溶出特性、矿物组成及微观结构进行了对比研究.结果表明,复合热活化之后的赤泥-煤矸石体系的胶凝性能明显提高.复合热活化过程中,赤泥的适量加入有助于房山煤矸石中绿泥石矿物的分解,且使石英的结晶度明显降低.当赤泥与煤矸石的比例为3:2,掺量为50%时,其复合体系所制备的胶砂试块28 d强度达到37.3 MPa.这为赤泥和煤矸石的大宗高效利用提供了试验依据和理论基础.