Method for chemical destroying of magnetic data carriers

Abstract

A method for chemically destroying magnetic data carriers. Recorded data are irretrievably eliminated and cannot be re-read. The carriers include aluminium or its alloys and ferromagnetic materials. They undergo a digestion reaction with an aqueous solution of a digesting mixture including: 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 reaction is an aqueous solution having aluminium hydroxide and chlorides and (V)nitrates of metals contained in the ferromagnetic metals and gaseous products of the reaction. Acidic salt solutions are utilized in a sewage treatment plant. Gaseous products including hydrogen and nitrogen oxides, after diluting with nitrogen, are directed to the atmosphere through an absorption system.

Claims

1. A method for chemical destroying of magnetic data carriers, wherein 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/or ammonium; or b) nitric(V) acid and chloride of one or more alkali metals, alkaline earth metals, rare earth metals and/or 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 materials as well as gaseous products of the reaction, whereas the magnetic data carriers, before being subjected to the digestion reaction, are fragmented into stripes with a width of 0.1 to 5 mm.

2. The method according to claim 1 wherein the aqueous solution of digesting mixture comprises the hydrochloric acid at a concentration of 1 to 20% by weight and the (V)nitrate of one or more alkali metals, alkaline earth metals, rare earth metals and/or ammonium at a concentration of 1 to 30% by weight, and a temperature of the aqueous solution of the digesting mixture is 20 to 90 C.

3. The method according to claim 1 wherein the aqueous solution of the digesting mixture comprises the nitric(V) acid at a concentration of 1 to 30% by weight and the chloride of one or more alkali metals, alkaline earth metals, rare earth metals and/or ammonium at a concentration of 1 to 20% by weight, and a temperature of the aqueous solution of the digesting mixture is 20 to 90 C.

4. The method according to claim 1, further comprising directing the aqueous solution comprising aluminum hydroxide and chlorides and (V)nitrates of metals contained in the ferromagnetic materials to a sewage treatment plant.

5. The method according to claim 1, wherein the gaseous products of the reaction comprise hydrogen and nitrogen oxides the gaseous products are diluted with nitrogen and are directed to the atmosphere through an absorption system.

6. The method according to claim 1, wherein the magnetic data carriers are hard disk platters.

7. The method according to claim 6 wherein the hard disk platters, before being subjected to the digestion reaction, are taken out from a hard disks casing after disassembling thereof by unscrewing or drilling or knocking out of screws with a screwdriver or an electric screw gun.

Description

DESCRIPTION OF PREFERRED EMBODIMENTS

(1) In the preferred embodiment the reaction of complete digestion of magnetic data carriers is performed with the use of an aqueous solution of hydrochloric acid with concentration of 1 to 20% by weight, in a mixture with an aqueous solution of (V)nitrate of one or more alkali metals, alkaline earth metals, rare earth metals and ammonium with concentration of 1 to 30% by weight, at temperature of 20 to 90 C.

(2) Preferably the reaction is performed with the use of an aqueous solution of hydrochloric acid with concentration of 10 to 20%, more preferably 15 to 20% by weight, in a mixture with an aqueous solution of (V)nitrate of one or more alkali metals, alkaline earth metals, rare earth metals and ammonium with concentration of 5 to 30%, more preferably 10 to 30%, and still more preferably 20 to 30% by weight.

(3) Preferably (V)nitrate of one or two alkali metals, alkaline earth metals, rare earth metals and ammonium is used.

(4) Preferably an aqueous solution of hydrochloric acid with concentration of 10 to 20% by weight and therein dissolved ammonium (V)nitrate with concentration of 1 to 10% by weight is used.

(5) Alternatively, the digestion reaction is performed with the use of an aqueous solution of nitric(V) acid with concentration of 1 to 30% by weight, in a mixture with an aqueous solution of chloride of one or more alkali metals, alkaline earth metals, rare earth metals and ammonium with concentration of 1 to 20% by weight, at temperature of 20 to 90 C.

(6) Preferably the reaction is performed with the use of an aqueous solution of nitric acid with concentration of 10 to 30%, more preferably 20 to 30% by weight, in a mixture with an aqueous solution of chloride of one or more alkali metals, alkaline earth metals, rare earth metals and ammonium with concentration of 10 to 20%, more preferably 15 to 20% by weight.

(7) Preferably chloride of one or two alkali metals, alkaline earth metals, rare earth metals and ammonium is used.

(8) Preferably an aqueous solution of nitric(V) acid with concentration of 15 to 25% by weight and therein dissolved sodium chloride with concentration of 5 to 15% by weight is used.

(9) According to the invention, the aqueous solution comprising acidic salt solutions as obtained in the digestion reaction is utilized in a sewage treatment plant. Gaseous products of the reaction comprising hydrogen and small amounts of nitrogen oxides, after diluting with nitrogen, are directed to the atmosphere through an absorption system, in which the nitrogen oxides are efficiently absorbed.

(10) The magnetic data carriers, before being subjected to the digestion reaction, are fragmented into stripes with the width of 0.1 to 5 mm.

(11) However, in more preferred embodiments the magnetic data carriers are fragmented into stripes with the width of 0.1 to 3 mm, and still more preferably of 0.5 to 1 mm.

(12) Preferably in the method of the present invention hard disk platters are subjected to the digestion reaction.

(13) The hard disk platters, before being subjected to the digestion reaction, are taken out from a hard disks casing after disassembling thereof by unscrewing or drilling or knocking out of screws with a screwdriver or an electric screw gun.

(14) The main advantage of the method of the present invention consists in complete and irretrievable destroying of the data carrier together with the data as recorded thereon and thus eliminating any possibility of re-reading the data in a later time.

(15) Other advantages resulting from the method of the present invention are: conducting of the entire chemical process in one reactor and in one solution, safety of performing the chemical process thanks to employing diluted acid solutions, environmental safety of the process for data carrier destroying as resulting from employing of the nitrogen oxide absorption and utilization of liquid final products of the reaction in a sewage treatment plant.

(16) The method for destroying data recorded on computer hard disks and other magnetic data carriers according to the present invention is particularly useful during erasing data in the following situations: handing the computer over to another user, sale of a computer used by a company, replacement of a faulty hard disk or a computer failure.

(17) The method according to the invention is particularly suitable for the computer users whose information, such as personal data of employees, payrolls, correspondence, payment cards numbers and bank account numbers, invoices, customers and clients lists, internal reports, statements, projects, and signature specimens, absolutely has to be permanently erased from any data carriers.

(18) The subject of the invention has been explained in more detail in the working examples.

Example 1

(19) 20 kg of aqueous solution of hydrochloric acid with concentration of 15% by weight and 1000 g of ammonium (V)nitrate were introduced into a glass reactor provided with a stirrer, an exhaust system, a nitrogen dispensing system and a cooling system. After dissolving of the salt in the solution of the acid, 25 hard disk platters fragmented into thin stripes with the width of 0.5 to 1 mm were introduced into the reactor. The stirrer, the nitrogen injection and the exhaust system were turned on. The digestion reaction of the magnetic data carriers was conducted in the temperature of about 90 C., until the complete digestion of the hard disk platters. The gases that had been liberated during the reaction were directed to the exhaust system through the absorption system. The solution obtained after the reaction was directed to a sewage treatment plant.

Example 2

(20) 21 kg of aqueous solution of nitric(V) acid with concentration of 20% by weight and 2100 g of sodium chloride were introduced into a reactor made of acid resistant steel provided with a stirrer, an exhaust system, a nitrogen dispensing system and a cooling/heating system. After dissolving of the salt in the solution of the acid, 20 hard disk platters fragmented into thin stripes with the width of 0.5 to 1 mm were introduced into the reactor. The stirrer, the nitrogen injection and the exhaust system were turned on. The digestion reaction of the magnetic data carriers was conducted in the temperature of about 90 C., until the complete digestion of the hard disk platters.

(21) The gases that had been liberated during the reaction were directed to the exhaust system through the absorption system. The solution obtained after the reaction was directed to a sewage treatment plant.