Phosphate Capacities of CaO–FeO–SiO2–Al2O3/Na2O/TiO2 Slags

To effectively increase the dephosphorization efficiency of hot metals or the previous stage in the converter steelmaking process, phosphate capacities {\rm{(}}{{\rm{C}}_{{\rm{PO}}_4^{3 - }}}) of CaO–FeO–SiO2–Al2O3/Na2O/TiO2 slags at 1300–1400°C were examined by laboratory experiments using equilibrating slag and pure solid iron foil. The data suggested that {\rm{(}}{{\rm{C}}_{{\rm{PO}}_4^{3 - }}}) increases with decreasing temperature and increasing slag basicity. Compared to basicity, temperature considerably affected the phosphate capacities and tended to be the most important factor. The phosphate capacities of slag considerably decreased at a high temperature of 1400°C even under high binary basicity as well as high contents of Na2O and FeO. Moreover, with the increase in the content of FeO and Al2O3 in the slag, {\rm{(}}{{\rm{C}}_{{\rm{PO}}_4^{3 - }}}) decreased. A low content of Na2O led to the increase in the phosphate capacities of slag, particularly at low temperatures of 1300–1350°C. The content of TiO2 in the slag considerably exhibited a weaker effect on {\rm{(}}{{\rm{C}}_{{\rm{PO}}_4^{3 - }}}). Furthermore, by regression analysis, {\rm{(}}{{\rm{C}}_{{\rm{PO}}_4^{3 - }}}) was expressed as a function of the temperature and slag compositions as follows: \eqalign{&{{\rm{log}}{{\rm{C}}_{{\rm PO}_4^{3 - }} = 0.041( \% {\rm CaO}) - 0.086{\rm log}({\rm{ \% }}{\rm FeO})} - 0.024( \% {\rm Si{O_2}})} \cr &{{ - 0.02({\rm{ \% }}{\rm A{l_2}{O_3})}} { + 0.067( \% {\rm N{a_2}O)} + 0.039( \% {\rm Ti{O_2})}}} \cr &+ 56767/{\rm T} - 14.58, ({\rm R} = 0.978)}}

Growth of Hematite Nanostructures in Iron Foil for Environmental Cleaning

Hematite (Fe2O3) nanostructures were successfully grown on the surface of iron foil by simple thermal oxidation in air. The iron foil was heated at 300 – 700 °C for 8 h to produce Fe2O3 nanosheets and nanowires. The oxide layer is primarily composed of Fe2O3 with a small amount of magnetite (Fe3O4) and wustite (FeO). The photocatalytic activity of the Fe2O3 nanowires was investigated by degradation of methyl orange dye under 30 W UV light in the presence of a minute amount of hydrogen peroxide. The Fe2O3 nanowires exhibit excellent photocatalytic activity, wherein 2.5 ppm of the methyl orange was fully decomposed in 30 min.

Improving the growth of monolayer CVD-graphene over polycrystalline iron sheets

A high quality graphene film, mostly composed of monolayer graphene, was successfully grown on polycrystalline iron foil by atmospheric CVD process using methane as carbonaceous source.

Effect of electric field on Fe2O3 nanowire growth during thermal oxidation

A direct current of 5 A was applied to narrow strips of iron foil in air to synthesize iron oxide nanowires (NWs) via thermal oxidation route of resistive heating. Transverse electric fields of 0–4000 V/m were applied perpendicularly to the surface of the iron foil during thermal oxidations. Results showed that the Fe2O3 NW array can grow perpendicularly on that surface by using this kind of thermal oxidation method. Transverse electric fields applied during thermal oxidation significantly affected the morphology of the Fe2O3 NW array. With increasing strength of the transverse electric fields, the Fe2O3 NWs became much longer, thinner and denser in distribution, and the diameters became more uniform. Furthermore, solid state based-up diffusion growth mechanism for the Fe2O3 NW array was confirmed by thermal oxidation.