Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. Resulting sulfates, produced from contaminants in the impure alumina, remain in solution at approximately 90 C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. Addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide. Carbon monoxide reduces the ferrous oxide to metallic iron. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.

Dendronized metallic oxide nanoparticles, a process for preparing the same and their uses.

Dendronized metallic oxide nanoparticles, a process for preparing the same and their uses.

Methods and composition are provided for deriving cement and/or supplementary cementitious materials, such as pozzolans, from one or more non-limestone materials, such as one or more non-limestone rocks and/or minerals. The non-limestone materials, e.g., non-limestone rocks and/or minerals, are processed in a manner that a desired product, e.g., cement and/or supplementary cementitious material, is produced.

The present invention relates to a metal oxalate hydrate body having a certain shape, a preparation method thereof, and a metal oxide/carbon composite body prepared by using the metal oxalate hydrate body. In the present invention, the metal oxalate body, whose shape is diversely controlled, and the metal oxide/carbon composite body therefrom are provided.

The present invention relates to a metal oxalate hydrate body having a certain shape, a preparation method thereof, and a metal oxide/carbon composite body prepared by using the metal oxalate hydrate body. In the present invention, the metal oxalate body, whose shape is diversely controlled, and the metal oxide/carbon composite body therefrom are provided.

A hydrogen gas production method includes a light irradiation step of applying light to a surface of a metal material immersed in water to produce gas containing hydrogen. In this hydrogen gas production method, the metal material contains iron, in the spectrum of the light, a wavelength at which the intensity is maximum is not less than 360 nm and less than 620 nm, and as the gas is produced, at least one of iron oxide and iron hydroxide is formed on the surface.

A method for producing crystalline ?-Fe.sub.2O.sub.3 nanoparticles involving ultrasonic treatment of a solution of an iron (III)-containing precursor and an extract from the seeds of a plant in the family Linaceae. The method involves preparing an aqueous extract from the seeds of a plant in the family Linacae and dropwise addition of the extract to the solution of an iron (III)-containing precursor. The method yields crystalline nanoparticles of ?-Fe.sub.2O.sub.3 having a spherical morphology with a diameter of 100 nm to 300 nm, a mean surface area of 240 to 250 m.sup.2/g, and a type-II nitrogen adsorption-desorption BET isotherm with a H3 hysteresis loop. A method for the photocatalytic decomposition of organic pollutants using the nanoparticles is disclosed. An antibacterial composition containing the crystalline ?-Fe.sub.2O.sub.3 nanoparticles is also disclosed.

A method for producing crystalline ?-Fe.sub.2O.sub.3 nanoparticles involving ultrasonic treatment of a solution of an iron (III)-containing precursor and an extract from the seeds of a plant in the family Linaceae. The method involves preparing an aqueous extract from the seeds of a plant in the family Linacae and dropwise addition of the extract to the solution of an iron (III)-containing precursor. The method yields crystalline nanoparticles of ?-Fe.sub.2O.sub.3 having a spherical morphology with a diameter of 100 nm to 300 nm, a mean surface area of 240 to 250 m.sup.2/g, and a type-II nitrogen adsorption-desorption BET isotherm with a H3 hysteresis loop. A method for the photocatalytic decomposition of organic pollutants using the nanoparticles is disclosed. An antibacterial composition containing the crystalline ?-Fe.sub.2O.sub.3 nanoparticles is also disclosed.

In a coloring ultraviolet protective agent, the average molar absorption coefficient in the wavelength range from 200 nm to 380 nm is increased, and the color characteristics in the visible region are controlled. The coloring ultraviolet protective agent is useful for shielding ultraviolet rays and coloring. The coloring ultraviolet protective agent comprises M2 doped oxide particles in which oxide particles (M1Ox) including at least M1 being a metal element or metalloid element, are doped with at least one M2 selected from metal elements or metalloid elements other than M1, wherein x is an arbitrary positive number, wherein an average molar absorption coefficient in the wavelength range of 200 nm to 380 nm of a dispersion in which the M2 doped oxide particles are dispersed in a dispersion medium, is improved as compared with one of a dispersion in which the oxide particles (M1Ox) are dispersed in a dispersion medium, and wherein a hue or chroma of color characteristics in the visible region of the M2 doped oxide particles is controlled.