Method for chemical destroying magnetic data carriers

The subject of the invention is a method for chemical destroying of magnetic data carriers, in particular hard disk platters, during which the recorded data are irretrievably eliminated and rendered impossible to be reread. In the method according to the invention the magnetic data carriers comprising aluminium or its alloys and ferromagnetic materials are subjected to a digestion reaction in a reactor with an aqueous solution of a digesting mixture that comprises: a) hydrochloric acid and (V)nitrate of one or more alkali metals, alkaline earth metals, rare earth metals and ammonium; or b) nitric(V) acid and chloride of one or more alkali metals, alkaline earth metals, rare earth metals and ammonium; the product of the digestion reaction is an aqueous solution comprising aluminium hydroxide and chlorides and (V)nitrates of metals contained in the ferromagnetic metals as well as gaseous products of the reaction. Acidic salt solutions are utilized in a sewage treatment plant. Gaseous products of the reaction comprising hydrogen and nitrogen oxides, after diluting with nitrogen, are directed to the atmosphere through an absorption system. The method provides a complete destroying of the data carrier together with the data recorded thereon, and thus eliminates any possibility of re-reading the data at a later time.