Disclosed herein are electrolyte bismuth calcium ferrites having high oxygen vacancy ion mobility. There can be provided an oxygen vacancy electrolyte material including bismuth calcium ferrites (Bi.sub.1-xCa.sub.xFeO.sub.3-).

The present invention provides a process that allows the oxidation of trivalent arsenic and ferrous ion, simultaneous with neutralization of the acid solution to be treated, the precipitation of arsenic and oxidized ferric iron added in a molar ratio Fe:As determined at a defined pH, all of the above with a high efficiency of precipitation of arsenic as ferric arsenate or scorodite, obtaining a final residue stable in the long term, characterized by their higher content of arsenic in a lower volume compared with the procedures described in the state of the prior art.

A battery comprising an acidified metal oxide (AMO) material, preferably in monodisperse nanoparticulate form 20 nm or less in size, having a pH <7 when suspended in a 5 wt % aqueous solution and a Hammett function H.sub.0 >12, at least on its surface.

According to the present invention, a composite including amorphous iron molybdate islands, shows a smaller island size and a uniform distribution of islands compared with a conventional composite including crystalline islands, and thus has a higher specific surface area, thereby exhibiting excellent activity as a catalyst.

A battery cell having an anode or cathode comprising an acidified metal oxide (AMO) material, preferably in monodisperse nanoparticulate form 20 nm or less in size, having a pH<7 when suspended in a 5 wt % aqueous solution and a Hammett function H.sub.0>12, at least on its surface.

A ferrite powder for bonded magnets capable of producing a ferrite bonded magnet having high BH.sub.max, and excellent in fluidity when converted to a compound, and having a high p-iHc value, and a method for producing the same, and a ferrite bonded magnet using the ferrite powder for bonded magnets, wherein an average particle size of particles obtained by a dry laser diffraction measurement is 5 m or less; a specific surface area is 1.90 m.sup.2/g or more and less than 2.80 m.sup.2/g; a compression density is 3.50 g/cm.sup.3 or more and less than 3.78 g/cm.sup.3, and a compressed molding has a coercive force of 2300 Oe or more and less than 2800 Oe.

A method for preparing an anion adsorbent may be provided, which comprises the steps of: mixing at least two metal salts with each other, thereby forming a stack structure in which cationic compound layers and anionic compound layers containing anions and water of crystallization are alternately stacked on one another; performing a first heat treatment on the stack structure to expand between the cationic compound layers, thereby preparing a preliminary anion adsorbent; and performing a second heat treatment on the preliminary anion adsorbent to remove the anions and the water of crystallization from the anionic compound layers while allowing at least one of the anions to remain, thereby preparing the anion adsorbent.

A ferrite powder for bonded magnets having a high iHc value usable even in a low temperature environment, a method for producing the same, and a bonded magnet using the ferrite powder and having high iHc value which can be used even in a low temperature environment, wherein a specific surface area is 2.20 m.sup.2/g or more and less than 3.20 m.sup.2/g; a compression density is 3.30 g/cm.sup.3 or more and less than 3.60 g/cm.sup.3, and a compressed molding has a coercive force of 3250 Oe or more and less than 3800 Oe.

A method for manufacturing a ferromagnetic-particle includes preparing a manufacturing apparatus including a single mode cavity that resonates with a microwave of a predetermined wavelength; a microwave oscillator electrically connected to the single mode cavity and configured to introduce the microwave of a predetermined wavelength into the single mode cavity; a pipe disposed to pass linearly through an inside of the single mode cavity, the pipe being formed of a dielectric material; and a pump configured to introduce, from one end of the pipe, an alkaline reaction liquid in which metal ions of a ferromagnetic metal and hydroxide ions are dissolved; and reacting the reaction liquid in the pipe, introduced by the pump, by introducing the microwave into the single mode cavity so as to generate the ferromagnetic-particle in the pipe.

A method for manufacturing a ferromagnetic-particle includes preparing a manufacturing apparatus including an induction heating coil; a radiofrequency power source electrically connected to the induction heating coil and configured to form an alternating field inside the induction heating coil; a pipe disposed to pass through the induction heating coil, in which at least a partial area of the pipe in an axial direction thereof is formed of a dielectric material and an area, which is nearer to one end of the pipe than the area formed of a dielectric material, is formed of a conductive material; and a pump configured to introduce, from the one end of the pipe, an alkaline reaction liquid in which metal ions of a ferromagnetic metal and hydroxide ions are dissolved; reacting the reaction liquid in the pipe, introduced by the pump, by forming an alternating field inside the induction heating coil; and generating the ferromagnetic-particle in the pipe based on the reaction of the reaction liquid in the pipe.