Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°−50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°−25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: A method for treating a component made of a copper-based alloy containing lead. The component has Pb and Pb salts on a surface thereof. The method includes the step of etching the surface of the component selectively to remove almost entirely the Pb and Pb salts from the surface. The etching includes treating the surface with an acidic aqueous solution that is a) a non-oxidizing acidic aqueous solution of an acid capable of forming soluble Pb salts or b) an oxidizing acidic aqueous solution of an organic acid mixed with peroxide. The method also includes the step of passivating the etched surface whereby to inhibit release of any Pb or Pb salts remaining in the component when the passivated surface is in contact with water.

Abstract: A catalyst is described for the preparation of isobutene by dehydroisomerization of n-butane consisting of a solid, granular support of porous gamma-alumina on the surface of which catalytic quantities of platinum, silica and preferably also one or more promotors are deposited. In a preferred form of embodiment this catalyst is used with a second catalyst which may be formed of Boralite B or a solid granular support of gamma-alumina on the surface of which catalytic quantities of silica are deposited. The present invention relates also to the process of dehydroisomerization of n-butane to isobutene in which the catalyst is used and the relative operating conditions.

Abstract: A crystalline, porous, synthetic material is disclosed, together with its related preparation process.Such a material of zeolitic character, containing silicon, titanium and iron oxides, corresponds, in its calcined and anhydrous state, to the following empi rical formulapHFeO.sub.2.qTiO.sub.2.SiO.sub.2wherein p has a value greater than zero and lower than or equal to 0.050, q has a value greater than zero and lower than or equal to 0.025, and the H.sup.+ of HFeO.sub.2 can be at least partly replaceable or replaced by cations.

Abstract: A catalyst is described for the preparation of isobutene by dehydroisomerization of n-butane consisting of a solid, granular support of porous gamma-alumina on the surface of which catalytic quantities of platinum, silica and preferably also one or more promotors are deposited. In a preferred form of embodiment this catalyst is used with a second catalyst which may be formed of Boralite B or a solid granular support gamma-alumina on the surface of which catalytic quantities of silica are deposited.The present invention relates also to the process of dehydroisomerization of n-butane to isobutene in which the catalyst is used and the relative operating conditions.

Abstract: A crystalline, porous, synthetic material is disclosed, together with its related preparation process.Such a material of zeolitic character, containing silicon, titanium and aluminum oxides, corresponds, in its calcined and anhydrous state, to the following empirical formula:p HAlO.sub.2.q TiO.sub.2.SiO.sub.2wherein p has a value greater than zero and lower than or equal to 0.050, q has a value greater than zero and lower than or equal to 0.025, and the H.sup.+ of HAlO.sub.2 can be at least partly replaceable or replaced by cations.

Abstract: A catalyst active in the polymerization of ethylene or the copolymerization of ethylene with unsaturated monomers consists of a nickel complex catalyst bonded to a polystyrene substrate, and definable by the general formula (I): ##STR1## where R, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 have the meanings given in the description.The preparation is described of the catalyst and its use in the polymerization of ethylene and the copolymerization of ethylene with other unsaturated monomers.

Abstract: The present invention relates to a process for the oligomerization of light olefins or mixtures thereof, wherein a reaction is brought about between olefins with a carbon number of between 2 and 20 and synthetic zeolites containing silicon, titanium and gallium oxides which in the calcined, anyhdrous state have the following empirical formula:pHGaO.sub.2 .multidot.qZTiO.sub.2 .multidot.SiO.sub.2,where p is of a value greater than zero and less than or equal to 0.050 and q is of value greater than zero and less than or equal to 0.025, with the H.sup.+ of HGaO.sub.2 being at least partly exchangeable or exchanged with cations.

Abstract: A process is disclosed for oligomerizing light olefins or mixtures thereof, which consists in reacting said olefins, possibly diluted with an inert gas, by means of synthetic zeolites containing oxides of silicon, titanium and iron, having, in their calcined and anhydrous state, the following empirical formula:pHFeO.sub.2. qTiO.sub.2.SiO.sub.2,wherein p has a value larger than zero and smaller than, or equal to, 0.050 and g has a value larger than zero and smaller than, or equal to 0.025, and the H.sup.+ of HFeO.sub.2 can be at least partially substitutable or substituted with cations.

Abstract: A process is disclosed for oligomerizing light olefins or their mixtures, which consists in reacting said olefins, possibly diluted with an inert gas, by means of synthetic zeolites containing oxides of silicon, titanium and aluminum, which have, in their calcined and anhydrous state, the following empirical formula:pHAlO.sub.2 .multidot.qTiO.sub.2 .multidot.SiO.sub.2'wherein p has a vlue larger than zero and smaller than, or equal to, 0.050 and g has a value larger than zero and smaller than, or equal to, 0.025, and the H.sup.+ of HAlO.sub.2 can be at least partially substitutable or substituted with cations.