Influence of flux additives on iron ore oxidized pellets

Six additives, i.e., limestone, lime, magnesite, magnesia, dolomite and light-burned-dolomite, were added for investigating their influences on the pellet quality. For green balls, adding lime and light-burned-dolomite makes the wet drop strength decrease firstly, and then increase with further increase of additive dosage. Ca(OH)₂ affects the bentonite properties at the beginning, but the binding property of Ca(OH)₂ will be main when the dosage is higher. The other four additives decrease the drop strength for their disadvantageous physical properties. For preheated pellets, no mater what kind of additive is added, the compressive strength will be decreased because of unmineralized additives. For roasted pellets, calcium additives can form binding phase of calcium-ferrite, and suitable liquid phase will improve recrystallization of hematite, but excessive liquid will destroy the structure of pellets, so the compressive strength of pellet increases firstly and then drops. When adding magnesium additives, the strength will be decreased because of the oxidation of magnetite retarded by MgO.     

Fluoridation and sintering of hydroxyapatite material and their mechanical properties

In the current work hydroxyapatite Ca10(PO4)6 ·OH2(HA) was sintered with the addition of 3 wt% aluminum isopropoxide(C9H21AlO3) powder and 3 wt % Teflon powder(-C2 F2-). Sample was prepared by following sol-gel technique. Obtained pellets of samples were sintered. For investigation of effects of temperature on microstructures and mechanical properties the samples were sintered at various temperatures. For studying the phase composition, microstructures and elemental analysis the sintered samples were characterized by X-rays diffraction(XRD), scanning electron microscopy(SEM) and energy dispersive X-rays diffraction(EDAX) respectively. After sintering the samples mechanical properties, i e, grains size, apparent density, Vickers hardness, bending strength and compressive strength were found to be 2.14-18.76 μm, 1.523 6-0.752 g/cm3, 3.60-0.600 GPa and bending strength 33.265 8-14.900 MPa, 75-33 MPa, respectively. As a result of sintering fluoridated composite material was obtained.     

膨润土的挤条成型及机械强度改良

利用脱色处理后的膨润土进行了挤条成型实验,并研究改良酸处理后的产品在挤条时的难易程度和型条的机械强度。考察了成型过程中水的用量、添加剂的用量对挤条过程以及型条机械强度的影响。结果表明,在膨润土的挤条成型中,每100 g膨润土中水的最佳用量为60 mL,成型润滑剂浓硝酸的最佳用量为5 mL,成型粘结剂田菁粉的最佳用量为2.5 g,挤条后的型材的机械强度由未酸化处理和及未加添加剂时的45 N/cm2增加到112N/cm2。     

Experimental Study of Wastewater Treatment of Reactive Dye by Phys-Chemistry Method

Wastewater, which involves easy-soluble reactive dyes, especially non-degradable dyes, is very difficult to decolor efficiently by normal processes such as coagulation process and biological treatment. The high chromaticity seriously hinders the reuse of reactive dye waste water. In this paper, a new method by bentonite adsorption and coagulation （PAC） is employed for removing color from synthetic dye waste water which contains reactive red K-2G, K-RN blue, K-GR blue, X-3B red, K-GN orange, KB-3G yellow, K-2BP red, K-RN yellow and K-6G yellow. Bentonite pretreated by 4% CTMAB and milled to 160 order screen is proven to the best decoloring agent. For a 100 mL reactive red K-2G sample （CODcr 400 mg/L, 25 000 chromaticity color）, 0.5 g bentonite pretreated and 2.5 mL PAC is enough to decolor wastewater up to 99.92% and the sediment time is short. Non-degradable dyes such as active red X-3B and K-GN orange are declored completely as well. Raw sewage （low chromaticity color） is decolored completely at a bentonite dosage of 0.00 1g. More researches prove the high practical value of this process.     

Antibacterial properties of TiO<Subscript>2</Subscript> ceramic pellets prepared using nano TiO<Subscript>2</Subscript> powder

Titanium dioxide (TiO₂) porous ceramic pellets with three dimension nano-structure were prepared using nano TiO₂ powder. The TiO₂ porous ceramic pellets were composed of TiO₂ nanoparticles with 14–16 nm in diameter and had porosity of 74.85%. The mean pore size of the TiO₂ porous ceramic pellets was 20.73 nm and the main pore size ranged from 3 to 16 nm. The mass loss of the TiO₂ ceramic pellets was less than 5% after 20 d immersion in water. The antibacterial properties of the TiO₂ pellets were studied. The sterilization rate of Colibacillus (hospital polluted water with bacterium) can reach 99% after 3 h photocatalytic process and these TiO₂ pellets are easy to be re-activated and cyclically be used. The shaping mechanism and photocatalysis sterilization mechanism of the TiO₂ pellets were discussed. Funded by the Applied Basis Research from Sichuan Province, the Research of Photo Purification to Environment with Nano TiO₂ (No. 05YJ029-010)     

小麦秸秆／改性膨润土基高吸水性树脂的制备

为了提高树脂的吸水率、抗盐性和重复吸水后的凝胶强度,本研究将预处理后的小麦秸秆,通过水溶液聚合法与丙烯酸、丙烯酰胺、 改性膨润土共聚合成高吸水性树脂。探讨交联剂用量、引发剂用量、单体质量比、丙烯酸中和度、预处理后的小麦秸秆和膨润土用量等单因素对树脂吸水率和吸盐水率的影响,并确定了合成的适宜条件。通过红外光谱对预处理后的小麦秸秆和合成的高吸水性树脂的结构进行了分析,对比了最佳条件下添加和不添加改性膨润土所制备的高吸水性树脂的吸液率、重复吸液率和重复吸液后的凝胶强度。结果表明:最佳条件下制得的树脂在蒸馏水和0.9 ％盐水中的吸液率分别为195.7g?g-1和24.2g?g-1,且最佳条件下添加改性膨润土比没有添加所制备的高吸水性树脂在吸液率、重复吸液率和重复吸液后的凝胶强度方面都明显改善。     

氯盐溶液对钠基膨润土垫层膨胀性能的影响

在废弃物渗透液中,复杂的化学物质能影响钠基膨润土垫层的吸水膨胀性能,研究不同价态及浓度的氯盐溶液对膨润土膨胀指数的影响,探究pH值及温度对膨润土膨胀性能的影响,利用X射线衍射仪及扫描电子显微镜对氯盐溶液处理后的膨润土进行表征分析。试验结果表明,高价态高浓度的氯盐溶液对膨润土的膨胀性能起抑制作用,膨胀指数最低为5 mL/2 g;单价态低浓度的NaCl溶液对膨润土的膨胀性能起促进作用,膨胀指数最高达到56 mL/2 g。XRD测试表明,氯盐溶液处理后的膨润土层间距由12.512 ?下降到11.856 ?;SEM测试分析发现,高价态氯盐溶液中的膨润土形貌由规则鳞片状转化为无规则絮凝状。在氯盐溶液浓度为0.04 mol/L、pH值为9及温度为90 ℃的条件下,膨胀指数提升近50%。在0.01 mol/L NaCl溶液、0.02 mol/L NaCl溶液和0.01 mol/L CaCl₂溶液中,膨润土吸水膨胀过程中凝胶态部分符合Fickian扩散模型,表明溶液水分子扩散速率小于膨润土凝胶态部分松弛速率。其他浓度氯盐溶液中,膨润土吸水膨胀过程中凝胶态部分符合non-Fickian溶胀过程,溶液水分子扩散速率与膨润土凝胶态部分松弛速率大致相同。     

膨润土改性与印染废水脱色研究

试验分别采用焙烧法、酸浸法（HCl）、盐浸法（NaCl）对辽宁钙基膨润土进行了改性处理,并利用改性膨润土对印染废水进行吸附脱色性能的研究。结果表明：改性膨润土的吸附性能优于天然钙基膨润土,其中500℃焙烧后改性的膨润土吸附效果最佳。最佳脱色工艺条件为：体系pH值1～3、搅拌时间20 min、改性土用量30 g/200 mL。经过处理的废水水样,色度去除率达到99.0%以上,化学需氧量（CODcr）为92.16 mg/L,达到了国家一级排放标准（GB8978-1996）。     

Effect of nano-ZrO2 on microstructure and thermal shock behaviour of Al2O3/SiC composite ceramics used in solar thermal power

The Al2O3-ZrO2(3Y)-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength of samples with 10vol% nano-ZrO2 sintered at 1480℃ were 3.222 g/cm3 and 160.4MPa,respectively.The bending strength of samples after 7 times thermal shock tests (quenching from 1000℃ to 25℃ in air medium) is 132.0MPa,loss rate of bending strength is only 17%.The effect of nano-ZrO2 content on the microstructure and performance of Al2O3-ZrO2(3Y)-SiC composite ceramic was investigated.The experimental results show that the bending strength of samples with above 10vol% nano-ZrO2 content has decreased,because the volume expansion resulting from t-ZrO2 to m-ZrO2 phase transformation is excessive;Adding proper nano-ZrO2 would be contributed to improve the thermal shock resistance of the composite ceramics.The Al2O3-ZrO2(3Y)-SiC composite ceramic has promising potential application in solar thermal power.     

程潮铁矿球团配加黏结剂试验研究

对程潮铁矿高压辊磨前后的铁精矿分别添加膨润土、有机黏结剂、复合黏结剂进行造球试验。结果表明,单独添加少量的膨润土或有机黏结剂,其生球爆裂温度指标合格,生球强度指标不合格;采用膨润土质量分数为2.0%、有机黏结剂质量分数为0.05%的复合黏结剂,其生球抗压强度为14.5N/个、生球落下强度为（0.5m）12.1次/个、生球爆裂温度为630℃、成品球抗压强度为3 024N/个,球团质量有较大的提高。     

新疆巴里坤县拉伊格来克膨润土矿Ⅰ矿段膨润土矿物学特征

拉伊格来克膨润土矿主要是由玄武岩、玄武安山岩及中酸性火山碎屑岩于火山盆地沉积,后经过流体作用发生水解蚀变而成。结合成矿地质背景,从矿物学角度研究了矿区Ⅰ号矿段膨润土的矿石特征、蒙脱石化学成分、物化性质、矿物组构、应用属性等,结果表明：蒙脱石平均含量68.01％; w （Al2O3）18.45％,含量相对较高;矿石胶质价（＞100 mL/15 g）、膨胀容（36.0 mL/g）、比表面积（395 m2/g）均偏高; ENa ＋/CEC＞69.0％; X射线衍射分析, d（001）在1.22～1.35 nm。综合认为该矿段膨润土主要属钠基和钙钠基,蒙脱石相对含量高,质地优,耐热性能强,是一种优质的膨润土矿产资源。     

Mechanisms of composite agglomeration of fluoric iron concentrate

The effect of composite agglomeration process (CAP) on fluoric iron concentrates sintering was investigated. The yield and quality of the sinter are greatly improved when using CAP assisted with heat airflow and enhancing magnesium oxide (MgO) contents. For conventional sintering of fluoric iron concentrate, due to lower viscosity of binding phase and higher fluidity of liquid phase, the sinter is formed with large thin-walled holes and the strength of the sinter is deteriorated consequently. The novel process forms composite agglomerate in which acid pellets are embedded in basic sinter. The pellets are solid with interconnecting crystals of hematite (Fe₂O₃) and magnetic (Fe₃O₄). For basic sintering, after adding MgO, the viscosity of the melting phase increases and the fluidity decreases; and calcium and aluminum silico-ferrites and magnesium ferrite are formed with perfect crystals and good sintering microstructure.     

Electrochemical performance of LiFePO4/（C＋Fe2P） composite cathode material synthesized by sol-gel method

A LiFePO4/(C+Fe2P) composite cathode material was prepared by a sol-gel method using Fe(NO3)3·9H2O,LiAc·H2O,NH4H2PO4 and citric acid as raw materials,and the physical properties and electrochemical performance of the composite cathode material were investigated by X-ray diffractometry(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM) and electrochemical tests.The Fe2P content,morphology and electrochemical performance of LiFePO4/(C+Fe2P) composite depend on the calcination tempera...     

纳米磁性膨润土复合材料表征及降解甲基橙研究

以纯化膨润土为原料,通过铁盐与膨润土浆液反应制备非均相纳米磁改性Fe3O4/膨润土复合材料,研究其对甲基橙的降解性能。结果表明,纳米磁性颗粒以Fe3O4附载于膨润土上形成磁性集合体,其对甲基橙废水等温吸附符合Langmuir等温吸附模型。在pH为7、温度为25℃、纳米磁性膨润土投加量为1g/L、H2O2投加量为2.5mmol/L、降解时间为120min条件下,对模拟甲基橙废水降解率达96%,CODCr去除率为94.7%,色度去除率为88.8%。     

Preparation and properties of ceramic facing brick from East-lake sediment

In order to utilize solid wastes, ceramic facing brick was made form East-lake sediment and some additives. The strength and freeze-thaw resistance of the samples were tested, and the crystal phases and microstructures were studied by XRD and SEM. The results indicate that the samples have a wide firing temperature range. The main crystal phases are CaAl2Si2O8, α-Al2O3, Fe2O3, which distribute uniformly in the samples. The sample have the best properties in the series ’Ca-Al-Si’, and water absorption (Wa) , porosity (Pa), bulk density (D), bending strength and compressive strength are 7.24%, 15.82%, 2.19 g.cm-3, 45.57 MPa and 56.81 MPa respectively, when the addition amount of East-lake sediment is 80% and the firing temperature is 1 100 ℃. In the series ’K-Al-Si’, the sample with the best properties was obtained when addition amount of East-lake sediment was 70% and firing temperature was 1 060 ℃. The water absorption, porosity, bulk density, bending strength and compressive strength are 7.62%, 16.37%, 2.15 g～cm-3, 39.26 MPa, and 50.81 MPa respectively. They all come up to the national standardization, and meet the needs of manufacturing production.     

酸改性膨润土处理苯酚废水的工艺研究

以辽宁膨润土和硫酸为主要原料制备了改性膨润土,并研究了改性膨润土吸附苯酚废水的工艺条件。结果表明：使用改性膨润土0.3 g处理浓度为20 mg/L的苯酚废水,固液比为6 g/L,常温吸附1.5 h,苯酚浓度去除率达到65%~70%;改性膨润土对高浓度苯酚的浓度去除率较低浓度的更好,浓度去除率达到75%。     

Synthesis and properties of novel epoxidized soybean oilmodified phenolic resin/montmorillonite nanocomposites

The novel epoxidized soybean oil-modified-phenolic resin/clay nanocomposites（ESO-M-PR/ CN） was prepared. The coupling agent-benzyldimethylphenylammonium chloride [C6H5CH2N^＋（CH3）2C6H5Cl^- , B2MP] was adopted to modify the interface between the organic and inorganic phases. The effect of the nanocomposite structure on its physical and chemical properties was discussed. During the synthesizing process of ESO-M-PR/CN, the phenol hydroxyl was etherified by ESO or ESO epoxy resin prepolymer to provide long ESO epoxy segments. Long ESO epoxy resin chain segments enhanced the crosslink density of ESO-M- PR/CN. The thermal and mechanical properties exhibit a significant improvement. The temperature at which a weight loss of 5% occurs increases from 287.1 ℃ to 402.3 ℃. The flexural strength increases by 25%, while the flexural modulus increases by 39%. Moreover, the properties of resin were enhanced by the effect of the inorganic nanoparticles, while the size of the nanomontmorillonites in the phenolic resin was characterized with a scanning electron microscope. The particle size of inorganic montmorillonites in the modified system is less than 100 nm.     

Effects of Ta addition on the microstructure and mechanical properties of Ti40Zr25Ni8Cu9Be18 amorphous alloy

The effects of Ta addition on the microstructure and mechanical properties of Ti₄₀Zr₂₅Ni₈Cu₉Be₁₈ bulk amorphous alloy were investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM), scan electron microscopy (SEM) and compressive testing. As a result, the addition of Ta (0-8at%) prompted the successive precipitation of quasicrystalline phase, CuTi₂ phase and bcc β-Ti solid solution. Additionally, the addition of less Ta content (3at%-5at%) led to the formation of amorphous matrix/nanoquasicrystal/CuTi₂ complex phase structure; and nanoquasicrystals, as reinforcement precipitates, improved the fracture strength of Ti-Zr-Ni-Cu-Be-Ta alloys, which led to the high compressive fracture strength 1856 MPa of Ta5 alloy. With increasing Ta content (5at%-8at%), although the ductile dendritic β-Ti solid solution was precipitated, the strength and plasticity decreased to a great extent resulting from the growth of quasicrystalline phase and CuTi₂ phase.     

Effect of heparin on high glucose induced proliferation and expression of matrix metalloproteinases in normal human mesangial cells

Background The pathogenesis of diabetic nephropathy (DN) is a complex pathophysiological process. Its precise mechanism is not fully known. In recent years it has been recognized that synthesis of various extracelluar matrix (ECM) components may increase, and that degradation of ECM may decrease in DN. It was reported heparin could inhibit mesangial cells proliferation in vitro. The main aim of this study is to explore whether heparin inhibits proliferation of mesangial cells grown in high glucose concentration and to measure the effect of heparin on matrix metalloproteinases (MMPs) expression in mesangial cells. Methods The medium contained either low glucose (5 mmol/L) or high glucose (25 mmol/L). The concentrations of heparin in the culture medium were 0, 25, 50, 100, 200 or 400 μg/mL. A metabolic (WST-1) assay was used to measure mesangial cell proliferation and Western blot analysis was used to measure MMPs expression of mesangial cells. Results Normal human mesangial cell (NHMC) proliferation was higher in high glucose (HG) medium than in low glucose (LG) medium. They showed a 1.93 fold expansion after 72 h in high glucose in contrast to a 1.63 fold expansion in low glucose. In the presence of heparin, mesangial cells proliferation was inhibited, which was more obvious at high glucose concentrations than at low glucose concentrations. In high glucose, with heparin concentration of 50, 100, 200 and 400 μg/mL, the mesangial cells showed a 0.61 fold, 0.52 fold, 0.52 fold and 0.41 fold reductions in cell number compared to cells grown without heparin. In low glucose, only concentrations of 200 μg/mL and 400 μg/mL showed reduction in cell number, namely 0.54 fold and 0.45 fold, when compared to cells grown without heparin. In Western blot analysis, MMP₁, MMP₂, MMP₃ and MMP₉ was expressed by mesangial cells expressed in both high and low glucose concentrations, which was more prominent in high glucose medium. Incubation of heparin further increased expression of MMP₁, MMP₂, MMP₃ and MMP₉. Conclusions This study suggests that glucose can accelerate mesangial cell proliferation while heparin can reduce proliferation, being more obvious at high glucose concentrations. Higher glucose concentrations led to increased MMP expression, which may take part in the regulation of mesangial matrix synthesis and degradation. Addition of heparin resulted in a corresponding increase in MMP expression, most notably at high glucose concentrations, indicating a potentially renoprotective role in DN. Foundation item: Project (30370663) supported by the National Natural Science Foundation of China     

Catalytic Decomposition of Nitric Oxide by LaCoO<Subscript>3</Subscript> Nano-particles Prepared by Rotary CVD

Catalytic direct decomposition of NO by perovskite-type catalysts has attracted much attention for the various possible components and the unique structure. LaCoO₃ nanoparticles were precipitated on α-Al₂O₃ micro powders by rotary chemical vapor deposition (rotary CVD) and its catalytic performance for the decomposition of NO was investigated. LaCoO₃ nano-particles with 100 nm in average diameter and 1.5% in mass were uniformly dispersed on α-Al₂O₃ powder. The conversion of NO increased with increasing temperature from 400 to 950 °C, and reached 28.7% at 950 °C. The gas velocity of transformed NO on LaCoO₃ nano-particles catalyst per mass unit was 7.7 mL/(g min), showing a good catalytic activity over the calculated results of pure catalysts. After five times of aging performance experiments, the NO conversion kept the same value, showing a good aging performance and thermal stability.