羟基氧化铁和活性炭催化异丙醇还原芳香族硝基化合物制备芳胺

将Na OH溶液快速滴加至Fe(NO3)3·9H2O和聚乙二醇(PEG)1 000的混合物中,制备了羟基氧化铁。用X-射线粉末衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)和激光粒度仪对制备的羟基氧化铁进行了表征。结果表明,羟基氧化铁为非晶态,在制备过程中加入PEG1000能使催化剂的颗粒较均匀、粒径较小。以羟基氧化铁和活性炭催化异丙醇还原10种芳香族硝基化合物得到了相应的芳胺,收率为53%~80%。     

鲁西地区铁矿类型特征及成矿谱系

山东省是中国的铁矿资源大省,其中鲁西地区铁矿成矿地质条件优越,铁矿类型有沉积变质型、接触交代型、热液交代充填-风化淋滤型、沉积型、岩浆型等多个成矿类型;其中尤以沉积变质型铁矿、接触交代型铁矿最为重要,是山东省的主要铁矿石来源。在梳理鲁西地区各种类型铁矿时空分布特点、分析典型铁矿床特征、控矿要素及矿床成因的基础上,以地质演化史为轴线,建立了鲁西地区各类型铁矿的成矿谱系。研究表明,在地质演化过程中,鲁西地区铁矿的形成是在海底火山喷发、地层沉积、岩浆侵入、区域变质、构造运动、风化淋滤等地质及成矿作用的高度耦合下形成的一系列地质产物;即在新太古代时期形成了沉积变质型铁矿(如韩旺式、苍峄式、杨庄式和济宁式铁矿)和岩浆型铁矿(如肖家沟式铁矿),在晚石炭世时期形成了沉积型铁矿(如山西式铁矿),在早白垩世时期形成了接触交代型铁矿(如莱芜式、莲子汪式铁矿)和热液交代充填-风化淋滤型铁矿(如朱崖式铁矿)。各种类型铁矿床具有地层控矿、岩体控矿、构造控矿和多要素共同控矿的特点。在铁矿勘查过程中,应按其成因类型和控矿要素进行有针对性的勘查部署,以此促进鲁西地区的铁矿勘查及研究工作整体水平得以提升。     

催化动力学光度法测定痕量铁

在硫酸介质中 ,Fe(Ⅲ )离子在活化剂邻二氮菲的存在下可催化抗坏血酸还原 (2 .6_二溴_4_硝基苯 )_3_(4_硝基苯 )三氮烯的褪色反应 ,据此提出了测定痕量铁的新方法 ,该方法的线性范围为 0～ 33μg/ 2 5mL ,检测限为 6 .9× 10 -3 μg·mL-1,将本法用于人发与自来水中铁的测定 ,结果满意 .     

基于纳米铁的类Fenton法降解水中的三氯生

 作为一种广泛存在的典型药品及个人护理品,三氯生（TCS）给生态环境和人体健康带来了潜在的威胁。以三氯生为目标污染物,采用实验室自行设计合成的零价纳米铁作为类Fenton试剂,研究了类Fenton法对三氯生的降解过程。单因素实验结果表明,三氯生的去除率随着纳米铁投加量和双氧水浓度的增加而增加;在溶液pH值为3时去除率最高;三氯生的初始浓度对去除率的影响不太明显。动力学分析表明三氯生的降解反应符合二级反应。在相同实验条件下,类Fenton试剂对三氯生的去除率明显优于传统Fenton试剂和单独投加纳米铁的体系。     

壳聚糖稳定纳米零价铁对土壤中Cr(Ⅵ)的去除

研究了壳聚糖稳定纳米零价铁对土壤中Cr(Ⅵ) 的去除效果. 实验结果表明: 去除效率随零价铁投加量的增加而增大, 最大去除效率达95.9%, 是100目铁屑去除效率的6倍; 土壤pH值和土壤中Cr(Ⅵ)的初始含量与去除效率成反比; 零价铁对土壤中Cr(Ⅵ)的去除是吸附作用与还原作用共同发生的结果; 纳米零价铁对Cr(Ⅵ)的还原过程符合伪一级反应动力学,其表观速率常数kobs为0.016/min.     

Development of carbon composite iron ore micropellets by using the microfines of iron ore and carbon-bearing materials in iron making

Iron ore microfines and concentrate have very limited uses in sintering processes. They are used in pelletization; however, this process is cost intensive. Furthermore, the microfines of non-coking coal and other carbon-bearing materials, e.g., blast-furnace flue dust (BFD) and coke fines, are not used extensively in the metallurgical industry because of operational difficulties and handling problems. In the present work, to utilize these microfines, coal composite iron oxide micropellets (2-6 mm in size) were produced through an innovative technique in which lime and molasses were used as binding materials in the micropellets. The micropellets were subsequently treated with CO₂ or the industrial waste gas to induce the chemical bond formation. The results show that, at a very high carbon level of 22wt% (38wt% coal), the cold crushing strength and abrasion index of the micropellets are 2.5-3 kg/cm2 and 5wt%-9wt%, respectively; these values indicate that the pellets are suitable for cold handling. The developed micropellets have strong potential as a heat source in smelting reduction in iron making and sintering to reduce coke breeze. The micropellets produced with BFD and coke fines (8wt%-12wt%) were used in iron ore sintering and were observed to reduce the coke breeze consumption by 3%-4%. The quality of the produced sinter was at par with that of the conventional blast-furnace sinter.     

铁尾矿物相分析及加气混凝土制备

 研究区域的铁矿尾矿SiO₂质量分数达55.88%, 其成矿地质环境独特而复杂。尾矿的组成以石英、闪石和斜长石为主, 是一种富含硅酸铁的低硅磁铁尾矿。将铁尾矿和硅砂分别粉磨25 和30 min, 在最大限度使用尾矿的条件下, 得出生产铁尾矿加气混凝土的优化方案, 成功制备出干密度为588 kg/m³, 抗压强度为3.99 MPa 的加气混凝土制品。通过XRD 和反应机理的分析结果表明, 成品中主要的物相为水化产物是0.9 nm 托贝莫来石、1.1 nm 托贝莫来石、1.4 nm 托贝莫来石和C-S-H 凝胶, 此外还有铁钙闪石、硬石膏、方解石和水化反应中残留的石英, C-S-H 凝胶作为“黏结剂”和托贝莫来石相互胶结成一个整体, 使制品得到较好的强度。     

Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873–1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.     

Effects of sintering atmosphere on the physical and mechanical properties of modified BOF slag glass

This study proposes an efficient way to utilize all the chemical components of the basic oxygen furnace (BOF) slag to prepare high value-added glass-ceramics. A molten modified BOF slag was converted from the melting BOF slag by reducing it and separating out iron component in it, and the modified BOF slag was then quenched in water to form glasses with different basicities. The glasses were subsequently sintered in the temperature range of 600–1000℃ in air or nitrogen atmosphere for 1 h. The effects of different atmospheres on the physical and mechanical properties of sintered samples were studied by using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) and by conducting experiment on evaluating the sintering shrinkage, water absorption and bulk density. It is found that the kinetics of the sintering process is significantly affected by sintering atmosphere. In particular, compared with sintering in air atmosphere, sintering in N₂ atmosphere promotes the synergistic growth of pyroxene and melilite crystalline phases, which can contribute to better mechanical properties and denser microstructure.     

钢铁烧结烟气多污染物的排放特征及控制技术

 监测了钢铁烧结烟气的排放特征,发现SO₂排放浓度沿着烧结机方向呈现机头和机尾低、中部高的特点,二噁英的排放浓度与烟气温度正相关,温度高于250℃时二噁英的排放浓度出现峰值.调研了数十台烧结机的烟气排放特征,表明SO₂排放浓度≤2000 mg/m³的占63%,要求脱硫效率大于90%;>2000 mg/m³的占37%,要求脱硫效率大于96%.NO_x排放浓度≤300 mg/m³的占86%,烟气无需脱硝可直接排放;在300~600 mg/m³之间的占14%,要求脱硝效率大于50%.二噁英排放浓度为1.0~5.0ng TEQ/m³,必须采取控制措施才能达标排放.针对烧结烟气SO₂和二噁英浓度高的特点,论述了基于活性炭吸附的活性炭法,以钙基吸收剂脱硫为主、活性炭(焦)脱二噁英为辅的SDA 法、MEROS 法、IOCFB 法等4 种多污染物协同控制技术及脱除效果.