Abstract: Solid superacid catalysts, in the form of spheres or microspheres, consisting of a mixed sulfated oxide of zirconium and of at least one other element selected from those of group 3, group 4, group 5, group 6, group 7, group 8 group 9, group 10, group 11, group 12, group 13, group 14, group 15 and those of the series of lanthanides, alone or combined with each other, are characterized in that they are obtained by means of a sol-gel process comprising the following steps: preparing a zirconium sol, mixed with a thickening agent and optionally with the element or elements selected; adding, only when microspheres are to be obtained, a non-ionic surface-active agent, to the sol; dripping, obtaining spheres, or atomising, obtaining microspheres, the sol into a basic gelation bath; ageing the spheres or microspheres of gel thus obtained; washing the spheres or microspheres with water up to pH=9; and draining them without drying them; impregnating the spheres or microspheres of gel with an aqueous soluti

Abstract: Equipment for the preparation of electric conducting composite samples by infiltration in a mold characterized in that it essentially comprises: a pressurization/infiltration chamber having at least one opening to connect it by means of appropriate tubes with a vacuum line and a pressure line and devices for sealing both under vacuum and under pressure; a sample-holder, inside said chamber, made of a material with a high thermal conductivity with one or more seats in each of which a mold is housed consisting of: a chemically inert and thermally stable tube made of a non-porous material; a plug, situated at one end of the tube, of a material which is different from the tube; a chemically inert and thermally stable spacer of non-porous material, situated inside the tube in contact with the plug; a device for creating a vacuum in the chamber; a device for pressurizing the chamber; a device for the thermal treatment of the sample-holder.

Abstract: Zirconia ceramic fibers, for catalytic applications, partially stabilized with yttria by means of a particular sol-gel process, are functionalized with a coating, containing zirconia and, optionally, alumina and/or oxides of Cu, Ni, Co, V, Mo, W, Ce, La, Nd and/or noble metals selected from Rh, Pt, Pd, Ru, Au, mainly obtained with a "dip coating" technique.

Abstract: This invention relates to a process for obtaining pure or mixed oxide zirconia spheres, microspheres or washcoats consisting of:preparing a zirconium solution in water at a concentration, formally expressed as ZrO.sub.2, equal or lower than 400 g/l, starting from a basic zirconium carbonate additioned of conc. nitric acid up to a molar ratio ?NO.sub.3.sup.- !/?Zr.sup.4+ ! between 0.8 and 1.1, and eventually preparing one or more solutions of the other oxides when necessary;preparing a sol of zirconium, eventually mixed to other metals, by a thickening agent and, in the case of spheres and microspheres, of a surface active agent too;dripping the sol into an alkaline gelation bath for obtaining gel spheres or microspheres, or sucking the sol into the honeycomb channels in order to obtain the washcoats, with subsequent gelation with gaseous ammonia;ageing the so obtained gel;rinsing with water down to pH=9-10, only in the case of gel spheres or microspheres;drying and calcining.

Abstract: The invention relates to the separation of indium from acidic solutions containing it, by means of the formation of complex compounds with complexing substances supported on either planar or tubular membranes, of ploymeric character, and of the de-complexing of the same, followed by a re-extraction or stripping with acidic solutions, which may be either of the same type of, or different from the starting solutions.