A sintered pelletized catalyst precursor comprising iron oxides, including haematite, and Cr.sub.2O.sub.3 and optionally one or more of Al.sub.2O.sub.3, ZnO, MnO.sub.2, MgO, and/or CuO, the pelletized catalyst precursor having an iron oxide content of 60 wt % to 95 wt %, when expressed as Fe.sub.2O.sub.3, and a Cr(VI) content of less than 0.1 wt %, is physically stable on ignition or when subjected to a reducing gas sufficient to reduce the haematite to magnetite.

A sintered pelletized catalyst precursor comprising iron oxides, including haematite, and Cr.sub.2O.sub.3 and optionally one or more of Al.sub.2O.sub.3, ZnO, MnO.sub.2, MgO, and/or CuO, the pelletized catalyst precursor having an iron oxide content of 60 wt % to 95 wt %, when expressed as Fe.sub.2O.sub.3, and a Cr(VI) content of less than 0.1 wt %, is physically stable on ignition or when subjected to a reducing gas sufficient to reduce the haematite to magnetite.

A catalyst precursor, suitable for use after reduction as a water-gas shift catalyst, is described, which is in the form of a pellet comprising one or more oxides of iron, wherein the catalyst precursor has a pore volume 0.30 cm.sup.3/g and an average pore size in the range 60 to 140 nm The precursor may be prepared by calcination of precipitated iron compounds at temperatures in the range 400-700 C.

A catalyst precursor, suitable for use after reduction as a water-gas shift catalyst, is described, which is in the form of a pellet comprising one or more oxides of iron, wherein the catalyst precursor has a pore volume 0.30 cm.sup.3/g and an average pore size in the range 60 to 140 nm The precursor may be prepared by calcination of precipitated iron compounds at temperatures in the range 400-700 C.

A method for extracting and recycling chromium from hexavalent chromium-containing residues includes the following steps: 1) adding water to the hexavalent chromium-containing residues and mixing uniformly; 2) adding sodium sulfate, sodium chlorate and sulfuric acid to a solution obtained in step 1) and stirring sufficiently to obtain a mixed liquid; 3) treating the mixed liquid by a hydrothermal method or direct heating; 4) after the heating treatment, naturally cooling a solid-liquid mixture to room temperature for holding; 5) separating solid residues and a chromium-containing supernatant, and washing filtered residues with water and then drying; 6) precipitating the supernatant and the water used for washing the filtered residues with a precipitant CaCl2, then centrifugally washing, dewatering and drying the precipitates; and 7) recycling a chromium-containing solution for returning to a work section, or for a treatment of recycling chromium.

A method for extracting and recycling chromium from hexavalent chromium-containing residues includes the following steps: 1) adding water to the hexavalent chromium-containing residues and mixing uniformly; 2) adding sodium sulfate, sodium chlorate and sulfuric acid to a solution obtained in step 1) and stirring sufficiently to obtain a mixed liquid; 3) treating the mixed liquid by a hydrothermal method or direct heating; 4) after the heating treatment, naturally cooling a solid-liquid mixture to room temperature for holding; 5) separating solid residues and a chromium-containing supernatant, and washing filtered residues with water and then drying; 6) precipitating the supernatant and the water used for washing the filtered residues with a precipitant CaCl2, then centrifugally washing, dewatering and drying the precipitates; and 7) recycling a chromium-containing solution for returning to a work section, or for a treatment of recycling chromium.

A magnetic material has: multiple soft magnetic alloy grains that contain Fe, element L (where element L is Si, Zr, or Ti), and element M (where element M is not Si, Zr, or Ti, and oxidizes more easily than Fe); a first oxide film that contains element L and covers each of the multiple soft magnetic alloy grains; a second oxide film that contains element M and covers the first oxide film; a third oxide film that contains element L and covers the second oxide film; a fourth oxide film that contains Fe and covers the third oxide film; and bonds that are constituted by parts of the fourth oxide film and that bond the multiple soft magnetic alloy grains together.

A magnetic material has: multiple soft magnetic alloy grains that contain Fe, element L (where element L is Si, Zr, or Ti), and element M (where element M is not Si, Zr, or Ti, and oxidizes more easily than Fe); a first oxide film that contains element L and covers each of the multiple soft magnetic alloy grains; a second oxide film that contains element M and covers the first oxide film; a third oxide film that contains element L and covers the second oxide film; a fourth oxide film that contains Fe and covers the third oxide film; and bonds that are constituted by parts of the fourth oxide film and that bond the multiple soft magnetic alloy grains together.

The present invention relates to structure including an interfacial seal between a glass-ceramic component and a metal component, as well as methods for forming such structures. In particular embodiments, the interfacial seal includes a metal oxide. Such interfacial seals can be beneficial for, e.g., hermetic seals between a glass-ceramic component and a metal component.

The present invention relates to structure including an interfacial seal between a glass-ceramic component and a metal component, as well as methods for forming such structures. In particular embodiments, the interfacial seal includes a metal oxide. Such interfacial seals can be beneficial for, e.g., hermetic seals between a glass-ceramic component and a metal component.