Effects Of Fe2O3 Research Articles

Effects of catalysts on combustion characteristics and kinetics of coal-char blends

The effects of Fe2O3, CaO, and MnO2 on the combustion characteristics and kinetics of coal-char blends were investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicated that catalysts exhibited positive effects on the combustion characteristics of coal-char blends, especially in the initial period of coal-char blends combustion. With catalysts addition (mass 1.5%), it could improves volatile matter release, and reduces ignition point, promotes char to begin burning under lower temperature. The ignition index (C) was increased, respectively, by 27% for Fe2O3, 6% for CaO, 11.3% for MnO2, and the combustion characteristic index (S) was increased respectively, by 29% for Fe2O3, 5% for CaO, 8.3% for MnO2. In addition, two kinetic models (R2 and F1) were adopted to calculate the kinetic parameters in different stage of combustion processes. The results showed that with Fe2O3 or CaO addition, the activation energy at second stage decreases from 86.0 KJ/mol to 76.92 KJ/mol and 75.12 KJ/mol, respectively. There are no obvious decreases at the third stage of samples combustion process.

Effects of Fe2O3 on the properties of ceramics from steel slag

Ferric oxide is one of the key factors affecting both the microstructure and the properties of CaO-MgO-SiO2-based ceramics. Research on this effect is significant in the utilization of iron-rich solid wastes in ceramics. Ceramic samples with various Fe2O3 contents (0wt%, 5wt%, and 10wt%) were prepared and the corresponding physical properties and microstructure were studied. The results indicated that Fe2O3 not only played a fluxing role, but also promoted the formation of crystals. Ceramics with 5wt% of Fe2O3 addition attained the best mechanical properties with a flexural strength of 132.9 MPa. Iron ions were dissolved into diopside, consequently causing phase transformation from diopside and protoenstatite to augite, thereby contributing to the enhancement of its properties. An excess amount of Fe2O3 addition (10wt% or more) resulted in deteriorated properties due to the generation of an excess volume of liquid and the formation of high-porosity structures within ceramics.

Effects of Fe2O3 on pyrolysis characteristics of soybean protein and release of NOx precursors

ABSTRACTThe effects of ferric oxide (Fe2O3) on the pyrolysis characteristics of soybean protein and the release of precursors to nitrogen oxides (NOx) were studied using thermogravimetry and mass spectrometry. The results show that, as the content of Fe2O3 increases, there is no major difference between initial and peak temperatures of protein pyrolysis samples. Moreover, between the temperature range of 204 and 550°C where weight loss mainly occurs, total weight-loss rate decreases before increasing, with obvious weight loss occurring around the temperature of 650°C. Fe2O3 displays both inhibiting and promoting effects on the precipitation of nitrogen-containing gases such as ammonia (NH3), hydrogen cyanide (HCN), isocyanic acid (HNCO), and acetonitrile (CH3CN), with the inhibition effect prevailing over promotion effect on the whole.

Fabrication of Porous SiAlON Using Fe<sub>2</sub>O<sub>3</sub> as Pore Former

Porous SiAlON ceramics were fabricated by carbo-thermal reduction nitridation method using Fe2O3 as pore former. Particle size effects of Fe2O3 were reported in this paper. The results showed that composites were composed by SiAlON, AlN and Iron Silicon phases. The median pore diameter of Sialon was affected by the composition and particle size of Fe2O3. The fracture mode of this material was intergranular. With the increase of Fe2O3 additions, the porosity of this materials increased. The bending strength of this material was reversely proportional to Fe2O3 particle size. The maximum bending strength of Porous materials with 30wt.% Fe2O3 additions (with a porosity about 65% and the pore size is about 1μm) could reach 22 MPa. The porous Sialon ceramics with a smaller pore size exhibited a higher bending strength.

Effect of some additives to the properties of paint from aluminum phosphate solution

This paper describes the effects of Fe2O3, ZnO and TiO2 in paint formulations with a binder component is aluminum phosphate solution. Through the evaluation of the mechanical properties as well as investigation on ability to resist electrochemical corrosion of the base film, we could asses the ability of anti-corrosion coating system. The results showed that the mechanical properties of the coating were better with the participation of Ti2O. In term of the effectiveness of corrosion resistance, the role of ZnO is very important.

The effects of Fe2O3 and Co3O4 on microstructure and properties of foam glass from soda lime waste glasses

Foam glasses are encountered as one of the most promising solutions for waste glasses recycling issues. Homogeneous pores distribution and high mechanical strength are two main characteristics of these products which many investigations have been done for their optimization. High flexural strength glass foams were fabricated by usage of oxidant agents like Fe2O3 and Co3O4 besides soda lime glass wastes and SiC as a foaming agent. Glass foams containing 4 wt % SiC and foamed at 850°C for 1 h had 90% porosity and bending strength of 0.75 MPa. Bending strength of specimens using increased to 6.82 MPa and porosity was decreased to 80% by addition of 1.2 wt % Co3O4. Moreover, the effects of Fe2O3 and Co3O4 on porosity, microstructure and mechanical properties of foam glasses were studied. Based on the results, the finest porosities with the highest size distribution homogeneity were observed in foam glasses contained Fe2O3 and Co3O4. Furthermore, Co3O4 addition produced slightly narrower pores size distribution in comparison with Fe2O3.

Influence of Iron Oxides on NO<sub>x</sub> Emission in Coke Combustion

NOx emission in coke combustion with and without iron oxides were investigated in a fixed bed quartz reactor. Effects of Fe2O3 and Fe3O4 loading on NOx emission were discussed. NOx emission was also studied by simulating test with recycling flue gas with Fe3O4 modified coke as fuel. The results showed that Fe3O4 was catalytically active in NOx reduction. In coke combustion experiments, NOx emission decreased with increasing Fe3O4 loading up to 2.0wt%, while simulation tests showed that NOx emission decreased by 19.84% with 2.0wt% Fe3O4 modified coke as fuel.

Microstructure, mechanical property, biodegradation behavior, and biocompatibility of biodegradable Fe–Fe2O3 composites

In this study, the effects of Fe2O3 (addition, 2, 5, 10, and 50 wt %) on the microstructure, mechanical properties, corrosion behaviors, and in vitro biocompatibility of Fe-Fe2O3 composites fabricated by spark plasma sintering were systematically investigated as a novel-structure biodegradable metallic material. The results of X-ray diffraction analysis and optical microscopy indicated that Fe-Fe2O3 composite is composed of α-Fe and FeO instead of Fe2O3. Both eletrochemical measurements and immersion test showed a faster degradation rate of Fe-2Fe2O3 and Fe-5Fe2O3 composites than pure iron and Fe-5Fe2O3 exhibited the fastest corrosion rate among these composites. Besides, the effect of Fe2O3 on the corrosion behavior of Fe-Fe2O3 composites was discussed. The extracts of Fe-Fe2O3 composite exhibited no cytotoxicity to both ECV304 and L929 cells, whereas greatly reduced cell viabilities of vascular smooth muscle cells. In addition, good hemocompatibility of all Fe-Fe2O3 composites and pure iron was obtained. To sum up, Fe-5Fe2O3 composite is a promising alternative for biodegradable stent material with elevated corrosion rate, enhanced mechanical properties, as well as excellent biocompatibility.

The stability of sapphirine + quartz: calculated phase equilibria in FeO–MgO–Al2O3–SiO2–TiO2–O

AbstractThe presence in rocks of coexisting sapphirine + quartz has been widely used to diagnose conditions of ultra‐high‐temperature (UHT) metamorphism (>900 °C), an inference based on the restriction of this assemblage to temperatures >980 °C in the conventionally considered FeO–MgO–Al2O3–SiO2 (FMAS) chemical system. With a new thermodynamic model for sapphirine that includes Fe2O3, phase equilibra modelling using thermocalc software has been undertaken in the FeO–MgO–Al2O3–SiO2–O (FMASO) and FeO–MgO–Al2O3–SiO2– TiO2–O (FMASTO) chemical systems. Using a variety of calculated phase diagrams for quartz‐saturated systems, the effects of Fe2O3 and TiO2 on FMAS phase relations are shown to be considerable. Importantly, the stability field of sapphirine + quartz assemblages extends down temperature to 850 °C in oxidized systems and thus out of the UHT range.

Variation of Char Structure during Anthracite Pyrolysis Catalyzed by Fe2O3 and Its Influence on Char Combustion Reactivity

Effects of Fe2O3 on the pyrolysis reactivity of demineralized anthracite were investigated by a thermogravimetric analyzer, indicating that pyrolysis reactivity of Fe2O3 loaded demineralized anthracite was higher than that of raw demineralized anthracite when temperature is over 500 degrees C, Chars were prepared from the two coal samples in muffle with heating progress, and their structures were analyzed using SEM, FTIR, XRD, and Raman. FTIR results showed that absorption peaks of functional groups on the surface of char from catalytic pyrolysis at 700 T were more than that of char from noncatalytic pyrolysis. Raman results demonstrated values Of (I-D3 + I-D4)/I-G,I- of chars from catalytic pyrolysis and noncatalytic pyrolysis were 4.76 and 3.86, respectively, indicating that ordering of the char was decreased by Fe2O3. XRD analysis revealed that diffraction angle of the 002 peak did not shift; however, 1,,, and 4, decreased, indicating degree of graphitization for microcrystalline structure of char from catalytic pyrolysis was decreased, The results of FTIR, XRD, and Raman of the chat, showed that catalytic pyrolysis improved the formation of free radicals, while hindered polymerization and forming of basic structure units. Finally, combustion reactivity of the three chars, including char of raw demineralized anthracite (char-A), char Of Fe2O3-loaded demineralized anthracite (char-B), and char. Of Fe2O3-loaded demineralized anthracite washed by HCl (char-C), was investigated using TG and indicated that their active order was char-B > char- C > char-A, The results corroborated that Fe2O3 changed structure of anthracite char and improved combustion reactivity.

Formation of magnesium niobates in the MgO-Nb2O5 system and the effects of Fe2O3

Formation of magnesium niobates in the MgO-Nb2O5 system and the effects of Fe2O3

Support and mixing effect of an Fe2O3 catalyst for oxidative dehydrogenation of 1-butene

The support and mixing effects of Fe2O3 for the activity of 1-butene oxidative dehydrogenation were examined. Alumina and titania which were able to catalyze the isomerization of butene via an allyl intermediate, stimulated remarkably the formation of butadiene from butene when they were used as support or mixing component of Fe2O3 catalyst. Otherwise Fe2O3 supported on SO42− ion containing Al2O3 or TiO2−Al2O3, which catalyze the isomerization via a cationic intermediate, is almost inactive for the formation of butadiene.

Fe<SUB>2</SUB>O<SUB>3</SUB>を含むスラグの粘度

Effects of Fe2O3 on the viscosity of silicate and ferrite slag melts have been studied in terms of the oxygen co-ordination number of Fe3+. Fe2O3 was amphoteric oxide like Al2O3 in these melts. Two parameters determining the behavior of Fe2O3 were proposed for these melts. One is the basicity of melts, and the other is the ratio of alkali (R2O)-, alkaliearth(RO)-oxide/Fe2O3 as seen for Al2O3. The portion of Fe3+ (4-co-ordinated oxygen) like Si4+ was increasing with increasing the basicity and/or the alkali-, alkaliearth-oxide/Fe2O3 ratio.In Na2O-Fe2O3 and BaO-Fe2O3 systems, the maximum was observed in viscosity-composition curves at the composition corresponding to Na2O or BaO/Fe2O3\fallingdotseq1. This could be explained by considering a change of the co-ordination number of Fe3+ with Fe2O3 content in the melts.