中国钢铁企业环境经营绩效的模糊综合评价

环境经营越来越受到中国企业界的重视.绩效评价具有多因素性、模糊性与综合性等特征.为客观全面评价中国钢铁企业环境经营的绩效水平,在构建环境经营评价指标体系的基础上,利用模糊综合评价方法与层次分析法建立多层次模糊综合评价模型,为企业进行环境经营绩效的评价提供参考.实证分析结果表明,该评价模型和体系具有可操作性.     

小鼠胰岛素样生长因子1(IGF1)基因启动子的生物信息学分析

生物信息学的发展为在线分析软件预测基因启动子的相关信息提供了众多有重要价值的参考信息.采用进化足迹法,结合生物信息学工具,运用在线软件进行分析,分析了小鼠IGF1基因的启动子结构.分析结果表明,在小鼠IGF1基因的启动子保守区内预测出6个转录因子结合部位,为探讨该基因的表达调控机制提供了重要参考.     

FeCl_3催化苯甲醛肟的合成研究

以环境友好型FeCl3为催化剂,在CH3CH2OH/H2O溶剂中合成苯甲醛肟.研究了催化剂种类及其用量、反应温度、溶剂等因素对反应的影响,通过对产物进行GC-MS和NMR分析,得到了合成苯甲醛肟的最佳反应条件为：苯甲醛3mmol、盐酸羟胺6mmol,溶剂乙醇与水的体积比15：1,在0.5equiv FeCl3的催化下,反应回流20min后,产率达到91.1%.     

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。     

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.     

白桦BpTCP7基因启动子的克隆及表达分析

【目的】研究BpTCP7启动子的表达模式,为深入分析BpTCP7基因功能提供一定参考。【方法】克隆了BpTCP7基因上游1 791 bp启动子序列,通过PLACE和Plant CARE网址对顺式作用元件进行分析,然后转入拟南芥,并分析BpTCP7启动子的组织表达特性及盐、旱胁迫应答反应。【结果】BpTCP7启动子序列中含有与细胞周期、开花、叶片发育、激素及胁迫响应等相关的顺式作用元件。该启动子在拟南芥中的表达模式呈现为营养生长阶段和生殖生长阶段均有表达,且在叶片中表达明显,与此同时,BpTCP7启动子在幼嫩、成熟叶片的边缘均有表达。与对照相比,NaCl、PEG胁迫诱导处理后BpTCP7基因表达量有升高的现象。【结论】BpTCP7基因参与白桦的叶片发育、激素应答、胁迫响应(盐、干旱)等生物学过程,对营养、生殖生长阶段各组织器官的发育也有一定的调控作用。     

黄铁矿烧渣提取铁、金、银等工艺研究

以黄铁矿烧渣为原料,通过化学选矿的方法,采用碱浸及氧化酸浸的工艺,除去有害杂质和回收有价金属元素金、银、铜,回收率分别为87%、76%、82%.同时得到品位为60.35%的铁精矿.     

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.     

Influence of acid leaching and calcination on iron removal of coal kaolin

Calcination and acid leaching of coal kaolin were studied to determine an effective and economical preparation method of calcined kaolin. Thermogravimetric-differential thermal analysis (TG-DTA) and X-ray diffraction (XRD) demonstrated that 900℃ was the suitable temperature for the calcination. Leaching tests showed that hydrochloric acid was more effective for iron dissolution from raw coal kaolin (RCK), whereas oxalic acid was more effective on iron dissolution from calcined coal kaolin (CCK). The iron dissolution from CCK was 28.78wt%, which is far less effective than the 54.86wt% of RCK under their respective optimal conditions. Through analysis by using M?ssbauer spectroscopy, it is detected that nearly all of the structural ferrous ions in RCK were removed by hydrochloric acid. However, iron sites in CCK changed slightly by oxalic acid leaching because nearly all ferrous ions were transformed into ferric species after firing at 900℃. It can be concluded that it is difficult to remove the structural ferric ions and ferric oxides evolved from the structural ferrous ions. Thus, iron removal by acids should be conducted prior to calcination.     

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.