METHOD OF TREATMENT OF ALUMINUM AND ITS ALLOYS EQUIPMENT DESIGNATED FOR OPERATION IN HYDROGEN PEROXIDE SOLUTIONS Russian patent published in 1996 - IPC

FIELD: methods of chemical treatment of equipment, pieces and structures of aluminum and its alloys designated for operation in hydrogen peroxide solutions of different concentration and also in chemical industry for production of hydrogen peroxide, in other branches of industry and national economy, that use hydrogen peroxide. SUBSTANCE: aim is to improve technical and economical parameters of process, that is to increase productivity, to decrease labour consumption, materials and power consumption, amount of sewage. Chemical treatment of equipment of aluminum and its alloys is carried out in one stage under temperature of 115 - 35 C with solution, that has sulfuric acid, hydrogen peroxide, phosphate and nitrate ions with following ratio of components, g/l: sulfuric acid - 10 - 250; phosphate ions - 0.006 - 0.7; nitrate ions - 0.07 - 0.3; hydrogen peroxide - 10-460. In the case treatment of equipment of technical sorts of aluminum is exercised for 18 -24 hours, of aluminum magnesium and aluminum manganese alloys - for 6 - 12 hours. EFFECT: increased productivity, decreased labour, materials and power consumption and sewage amount. 1 tbl