Effect of Iron Oxides on Activity of Calcium Aluminate Clinker in CaO-Al_2O_3-SiO_2 System

The sintering characteristics at 1350℃ and leaching property at 80℃ of calcium aluminate clinkers in the CaO-Al2O3-SiO2 （C-A-S） system with different additions of FeO and Fe2O3 were investigated. FeO inhibits the conversion of β-Ca2SiO4 to γ-Ca2SiO4 and makes the clinker not pulverizable. FeO and Fe2O3 inhibit the formation of CaAl2O4, but promote the formation of Ca12Al14O33. The interplanar spacing at （2 1 1） crystal face of Ca12 Al14O33 in the clinker increases with the increase of FeO addition, which indicates that FeO forms solid solutions in Ca12Al14O33. The clinkers with Fe2O3 addition form a new phase Ca2Fe2O5, and the amount of Ca2Fe2o5 increases with the in crease of Fe2O3 addition. Both FeO and Fe2O3 do not affect the Al2O3 leaching rate of calcium aluminate clinker in sodium carbonate solution, but they increase the molar ratio of caustic Na2O to Al2O3 in the leached liquor.     

FeO(OH)胶体加载微生物絮凝剂及其脱色特性

在未经人工培养的啤酒厂活性污泥中,以水合氧化铁胶粒吸附微生物絮凝剂并加载于其表面,应用于混凝脱色,建立了一种聚集微生物絮凝剂和增效的实用方法。研究了pH值、调pH值的时机、上清液与水合氧化铁溶胶投量比以及Ca^2 的存在对脱色效果的影响,结果表明：pH值为10;上清液与水合氧化铁溶胶投量比为1．5;pH值的调节在FeO(OH)溶胶加入之前,直接黄染料(DY4)的最高脱色率达98．7％。Ca^2 对本系统无明显作用。     

绿色氧化剂K2FeO4对瓜尔胶的降解实验研究

瓜尔胶在油田压裂液中作为稠化剂被广泛使用,作业后的压裂返排液中瓜尔胶难以自然降解,对环境造成严重危害;探索绿色高效处理油田压裂返排液的方法成为研究的热点和难点.本实验以K2FeO4为绿色高效氧化剂,对模拟压裂返排液(质量浓度为0.3‰瓜尔胶溶液)进行了降解实验研究,结果表明,当K2FeO4用量为0.5 g/L,反应温度30 ℃,反应pH值为12.0时,溶液降黏率最大可达89.27%,COD去除率为36.27%,且氧化剂反应为三价铁离子,绿色无污染.     

Mössbauer spectroscopy,XRPD, and SEM study of iron-containing Na2O-B2O3-SiO2 glasses

Glasses in the Na₂O-B₂O₃-SiO₂-Fe₂O₃ system are suitable for producing magnetic porous glasses—host matrices for multiferroic composite materials for spintronics applications. Successful synthesis of such materials is dependent on the knowledge of crystallization and immiscibility areas in this system. Here, we report new findings for such glasses with a constant SiO₂ concentration of 70 mol %, containing 7-12 mol % Fe₂O₃, whose compositions lie in the low (2 mol % Na₂O) and higher (8-12 mol % Na₂O) alkali regions, heat-treated at 550°C. Glasses were studied using analytical chemistry methods and investigated by means of Mössbauer spectroscopy, XRPD and SEM. We outlined the immiscibility area boundary in the chosen silica cross-section for 550°C, indicating the region of interconnected morphology and the crystallization fields of magnetite and FeSiO₃, and correlated them with data on the valence and coordination state of iron in glasses. We find that both Fe³⁺ and Fe²⁺ ions in the low-alkali region are octahedrally coordinated, in higher alkali area Fe³⁺ and Fe²⁺ are tetrahedrally and octahedrally coordinated, respectively. A significant amount of Fe²⁺ in the low-alkali region can be the cause of the FeSiO₃ formation. The usual crystalline phase in non-X-Ray amorphous glasses is magnetite, precipitating at the annealing stage.     

纳米晶La0.7Pb0.3FeO3的制备及其对CO敏感特性的研究

利用溶胶-凝胶法制备了纳米晶La0.7Pb0.3FeO3气敏材料,并对其相组成、电导及其对CO气敏性能进行了研究.XRD结果表明：掺铅固溶体La0.7Pb0.3FeO3仍为正交晶系钙钛矿结构,粒径约为17nm,低于纯相LaFeO3的粒径31nm。电导测鼍显示：该材料足P型半导体导电行为，电导大于同温度下纯相LaFeO3的电导，且电导突变温度有所降低。气敏性能研究表明：Pb掺杂对其CO气敏性能有了明显改善。     

纳米晶La_(0.7)Pb_(0.3)FeO_3的制备 及其对CO敏感特性的研究

利用溶胶-凝胶法制备了纳米晶La0.7Pb0.3FeO3气敏材料,并对其相组成、电导及其对CO气敏性能进行了研究。XRD结果表明:掺铅固溶体La0.7Pb0.3FeO3仍为正交晶系钙钛矿结构,粒径约为17nm,低于纯相LaFeO3的粒径31nm。电导测量显示:该材料呈p型半导体导电行为,电导大于同温度下纯相LaFeO3的电导,且电导突变温度有所降低。气敏性能研究表明:Pb掺杂对其CO气敏性能有了明显改善。     

钛白废酸在过磷酸钙生产中的应用

硫酸法钛白粉生产会产生w（H2SO4）21％、w（FeO）5．6％的废酸,如直接用于过磷酸钙生产,因FeO存在会造成硫酸输送管道堵塞,过磷酸钙结块和有效磷退化。介绍除去废酸中FeO的工艺技术,可使酸中的Ⅲ（FeO）降至0．27％。几年来回收废酸（折纯100％）4．63万t,合计创效益3240万元。     

La0.7Sr0.3FeO3对SnO2基CO气敏元件性能的影响

采用柠檬酸盐法合成纳米晶La0.7Sr0.3FeO3。为考察其对以SnO2为基体材料的一氧化碳气敏元件性能的影响,将一定质量分数的(1%、3%、5%)La0.7Sr0.3FeO3作为掺杂剂掺入SnO2粉体中。测试结果表明,La0.7Sr0.3FeO3的掺入改善了气敏元件的长期稳定性,同时提高了元件对CO气体的灵敏度,经10 d的老化后,80 d内元件阻值变化不超过±10%。用4A分子筛对元件进行表面修饰,改善了元件的选择性。     

氨基功能化磁性FeO(OH)纳米棒的制备研究

在获得表面修饰氨基官能团的磁纳米棒,为进一步偶联生物分子制备出磁生物双靶向纳米药物奠定基础.以部分氧化法制备了磁性FeO(OH)纳米棒,并在保持原有形貌的基础上对其进行硅胶包覆和氨基功能化,从而获得功能化磁纳米药物载体.磁纳米棒的形貌特征、晶体结构、磁性质和表面基团分别通过TEM(SAED)、XRD、VSM和FTIR进...     

马钢8m2球团竖炉适宜空、煤气比的研究

本文从理论上论述了马钢一烧 8m2 球团竖炉适宜的空、煤气配比。生产实践证明 ,马钢竖炉采用高炉煤气作燃料 ,空、煤气比为 1 1左右 ,燃烧废气的O2 含量约为 4 0 % ,燃烧室废气温度为 10 5 0℃ ,球团矿抗压强度大于 30 0 0N/个 ,利用系数为 6 7t/(m2 ·h) ,FeO含量为 0 85 % ,球团矿的产质量都较为满意。