Papers by Keyword: Ferric Oxide

Abstract: A method for the synthesizing of carbon composites based on hydrolysis lignin powders and iron oxides (FeO and Fe₂O₃) was proposed in this work. The obtained composites were studied by X-ray diffractometry, adsorption/desorption gas porometry and magnetometry. X-ray phase analysis has revealed the presence of an amorphous carbon phase and crystalline phases of FeO, Fe₃O₄, Fe₂O₃, and Fe in both types of synthesised composites. The synthesized composites demonstrated significantly higher specific magnetisation values compared to the initial iron oxide powders. For Fe₂O₃ powder, the specific magnetisation was σ_s = 6 A·m²/kg, while the saturation specific magnetisation of the composite based on this oxide was σ_s = 34 A·m²/kg. For FeO powder, the specific magnetisation was σ_s = 28 A·m²/kg, with the composite based on it exhibiting a specific saturation magnetisation of σ_s = 40 A·m²/kg. The observed results were explained by the formation of particles with sufficiently high values of specific magnetisation due to thermal reduction of iron oxides in the presence of carbon monoxide, obtained from the pyrolysis of hydrolysed lignin.

Abstract: Recycling of aluminium alloys is gaining significant attention due to its economic and environmental benefits. However, close loop recycled aluminium alloys can be adversely affected by impurities and alloying elements present in the recycled feedstock. In this study, the influence of three composites, namely alumina (Al₂O₃), ferric oxide (Fe₂O₃), and manganese (Mn), on the properties of recycled aluminium taldon scraps was investigated to enhance the tensile behaviour of the alloys. The effects of these composites on the mechanical properties, microstructure, and corrosion behaviour of the recycled aluminium alloys were evaluated through experimental characterization techniques. The results showed that the addition of these composites had a significant influence on the properties of recycled aluminium alloys, providing insights into the potential for improving the performance of recycled aluminium alloys through composite additions. The addition of Al₂O₃ enhanced the tensile strength by 44.18 % and the variation can be attributed to the strengthening of the dendritic zones by the formation of α-Al.

Abstract: Ferric oxide nanoparticles are environmentally benign and can be selective toward lead, especially in neutral to mildly alkaline pH of groundwater. However, due to very fine particles and low mechanical strength, it prevents these materials to apply in point of use filter or large scale fixed-bed adsorption. In this study, polymeric gel cation exchanger, Purolite C100, supported ferric oxide nanoparticles, C100-Fe, was synthesized, characterized, and tested with challenging water according to NSF standards 53. From SEM-EDX studies, it can imply that high concentration of iron can be doped and distributed within the gel phase structure of the C100 approximately 22% by mass. The TEM micrographs confirm the size of hydrated ferric oxide fall into the nanometer range about 10-60 mm. The fixed-bed adsorption experiments demonstrated that C100-Fe can remove lead below the stringent standard of 0.05 mg/L up to 15,000 BVs, whereas the GAC, GAC-Fe, and C100 can treat the same test water only 1200, 1700, and 3500 BVs, respectively. The results confirm that C100-Fe can be efficiently substituted to the traditional GAC for lead removal in drinking water.

Abstract: This study was to examine the effects of ferric oxide contents, which is one of the components of a newly developed glass, on the color and mechanical strengths of zirconia surfaces after glass infiltration. The composition of bioactive glass contained: SiO₂–Al₂O₃–Na₂O–MgO–BaO–CaO–Nb₂O₅–TiO₂–Fe₂O₃. 84 presintered zirconia discs (diameter 15 mm, height 1.2 mm) were prepared. The experimental groups were divided into 6 groups by Fe₂O₃ contents of 0, 1, 1.5, 2.0, 2.5 and 2.9 wt%. Non-glass infiltrated zirconia was used as a control. Bioactive glass was coated on the presintered zirconia disc by a spin coating and infiltrated into zirconia by complete sintering at 1450°C for 2 hr. The color of the specimens was measured using a digital spectrophotometer and biaxial flexural strength and fracture toughness was compared. The colors of glass infiltrated zirconia were from yellow to yellowish orange according to ferric oxides contents and those were within the range of natural teeth colors. The mechanical properties of glass infiltrated zirconia were not inferior to those of zirconia. Glass infiltration with ferric oxide into zirconia can improve the color and mechanical properties of zirconia and be applicable for dental purpose.

Abstract: Reduction of iron oxide by hydrogen is important in the production of direct reduced iron. This method of iron production is gaining increasing significance as an alternative route to the blast furnace technology with the many difficult issues facing the latter, the most important being the problem related to environmental. In order to reduce the emission of greenhouse gases CO₂, particularly for iron making, the production of Direct Reduced Iron (DRI) using hydrogen as the reducing gas instead of carbon monoxide is being considered. Reduction of pure hematite by hydrogen was studied at the laboratory scale, varying the experimental conditions like temperature (700oC and 800oC) and porosity (20% and 40%). Then, a Kinetic Modelling was conducted using Matlab software based on independently measured physical and thermodynamic properties of the reaction system and experimentally measured properties of the reactant solid (Fe₂O₃), gas phase (H₂) and reactant product (Fe). There is a gap that occurs between the predicted result and the experimental result although the model explicated the trend and the behaviour of the reduction rate of Ferric Oxide and indicated a good homogeneity to the experimental conditions used in this research.

Abstract: Ammonium sulfate, ammonium bisulfate and ferric oxide are mixed at a molar ratio of 8:5:13 and heated in high temperature muffle furnace or fluidized bed at different temperature. To the sample, the thermal gravimetric (TG) analysis is used, the reaction residue is analyzed by fourier transform infrared spectroscopy (FT-IR) and chemical analysis, the generated gas is qualitatively analyzed as well. The process of thermal decomposition for ammonium sulfate and ammonium bisulfate via addition of Ferric oxide has four stages-the decomposition of ammonium sulfate, the formation of ammonium ferric pyrosulfate, the decomposition of ammonium ferric pyrosulfate, and the decomposition of ferric sulfate. The ammonium ion in sample is completely decomposed at about 500°C. The decomposition ratio of sulfate ion or bisulfate ion is up to 99.8% above 800°C.

Abstract: For the purpose of developing an effective Fe₂O₃-doped nickel-based catalysts to be used in biomass gasification, Fe₂O₃ nanoparticles were prepared by homogeneous precipitation method involving an aqueous solution of Fe (NO₃)₃·9H₂O and urea as precipitator. Different approaches, such as XRD and SEM, were used to characterize the products. Meanwhile, the effects of various technical parameters in preparation process on the yield of products were investigated, and optimal conditions for preparing Fe₂O₃ nanoparticles were found as follows: the molar ratio of urea to Fe (NO₃)₃·9H₂O for 5:1, temperature of precipitation reaction for 125°C, concentration of iron salt for 0.20mol/L. The Fe₂O₃ nanoparticles prepared under the optimal conditions were spherical in shape and well dispersed; they had high purity and a fine crystal phase of cubic syngony with a mean particle size of about 28nm.

Abstract: Nanoparticles with about 20nm diameter were densely coated on the surface of submicron Al via a sol-gel processing in ethanol, wherein 1,2-epoxypropane acted as a weak base to consume proton in solution. After the medium gelled, uniform network formed and aluminum particles imbedded in it. The core-shell structure and the nanoparticles were observed in SEM analysis. The EDS spectrum and the XRD pattern revealed that the cores consisted of amorphous ferri-oxide of which the mass ratio is closed to that of crystal Fe₂O₃. Thermal analysis was performed and the results indicated that the DSC peak point of ferri-oxide/Al nanocomposite showed 53 °C lower than that of [ferri-oxide+A simple mixture.

Abstract: Fe₂O₃/H₂O₂, a kind of Fenton-like agent, was used to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing temperature. The SDBS degradation ratio will increase by, respectively, increasing H₂O₂ concentration and Fe₂O₃ dosage at some extent, but too high H₂O₂ concentration or Fe₂O₃ dosage will decrease the degradation efficiency. pH value has some influences on the reactivity of the system; from 2 to 10, the system maintains high efficiencies all the time. It also can be seen that Fe₂O₃/H₂O₂ Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former has a widely pH range (2-10), and Fe₂O₃ can be separated easily and has no secondary pollutants.

Abstract: Fe₂O₃ and Fe₂O₃/attapulgite(ATP) catalyst was used for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Comparative studies indicated that Fe₂O₃/ATP-catalyzed Fenton system and Fe₂O₃-catalyzed Fenton system have the same catalysis capability. These two systems all have a widely pH range (2-10), and the catalysts can be reused and have no secondary pollutants. It also can be seen that Fe₂O₃/ATP-catalyzed Fenton-like reaction has much efficiency than Fe₂O₃-catalyzed Fenton reaction.