Abstract: The present invention relates to an additive for fuels such as diesel fuel and fuel oil, used respectively for diesel engines and boilers of various types, comprising a metal oxidation catalyst, an organic nitrate and a dispersing agent in suitable ratios, capable of improving combustion efficiency in such a way as to reduce the formation of particulate matter and consumption.

Abstract: An additive composition for fuels such as diesel oil and fuel oil, used respectively for diesel engines and boilers of various types, containing a metal oxidation catalyst, in which the metal is iron, cerium, calcium, or their binary or ternary mixtures, an organic nitrate and a dispersing agent. The additive composition is able to reduce the formation of particulate emitted by diesel engines and boilers.

Abstract: An additive for fuels such as diesel oil and fuel oil, used respectively for diesel engines and boilers of various types, is described, comprising a metal oxidation catalyst, an organic nitrate and a dispersing agent in suitable ratios, able to improve combustion efficiency in such a way as to reduce the formation of particulate by as much as 90%.

Abstract: Stainless steel pickling process in which a pickling solution containing HF and Fe3+ ions as essential components is used, and wherein the oxidation to Fe3+ of the Fe2+ formed during the process in order to maintain the Fe3+ concentration to the predetermined value, is electrolytically carried out by submitting the pickling solution as it is to an oxidation process in an electrolytic cell equipped with anode made of inalterable materials chosen among graphite, granular coal, lead and with cathodes made of stainless steel, graphite or other unalterable materials, said cell working with an applied tension between 1 and 8 V and with an anodic current density between 0.4 and 15 A/dm2.

Abstract: Process for stainless steel pickling consisting in placing the material to be treated in a bath kept at a temperature ranging from 30.degree. C. to 70.degree. C. and containing:a) HClb) Fe.sup.3+c) HFd) emulsifiers, wetting agents, polishing agents, acid attack inhibitors;the bath being fed continuously with:an air flow equal to at least 3 m.sup.3 /h per m.sup.3 bath min. and an oxidizer quantity adjusted to the bath redox potential to be kept at 250 mV min.

Abstract: Process for stainless steel pickling consisting in placing the material to be treated in a bath kept at a temperature ranging from 30.degree. C. to 70.degree. C. and containing:a) H.sub.2 SO.sub.4b) Fe.sup.3+c) HFd) emulsifiers, wetting agents, polishing agents, acid attack inhibitors;the bath being kept under agitation with:an air flow and continuously fed with a quantity of oxidizing agent adjusted to the bath redox potential to be kept at 250 mV min.

Abstract: An acid aqueous solution useful for phosphating metal surfaces and a phosphating process using same; said solution, which is characterized by its containing hydroxylamine phosphate as accelerator and a cationic surfactant can be applied to metal surfaces based on iron, zinc, aluminium and alloys thereof, and is specifically suitable for preventing the formation of white spots.

Abstract: An acid aqueous solution useful for phosphating metal surfaces and a phosphating process using same; said solution, which is characterized by its containing hydroxylamine phosphate as accelerator and a cationic surfactant, preferably a quaternary ammonic surfactant, can be applied to metal surfaces based on iron, zinc, aluminium and alloys thereof, and is specifically suitable for preventing the formation of white spots.

Abstract: Process for sheet titanium pickling followed by passivation. Pickling is carried out in an aqueous solution containing H.sub.2 SO.sub.4, HF and Fe.sup.3+ at .ltoreq.50.degree. C., continuously fed with an air flow, and with a stabilized H.sub.2 O.sub.2 quantity adjusted to the bath redox potential to be kept at -200 to 0 mV. Passivation is carried out in an aqueous bath containing 4 to 10 g/l HF, .ltoreq.1 g/l Fe.sup.3+, and not containing H.sub.2 SO.sub.4, with a redox potential kept at 500-600 mV by continuous feeding of stabilized H.sub.2 O.sub.2.