WO1996009423B1 - Organically-based agent for removing rust from surfaces, production and use of said agent - Google Patents

Abstract

The invention concerns an agent, based on organic compounds obtained from micro-organisms, for removing rust from metal surfaces corroded with iron oxides. Rust is normally removed from metal articles using corrosive baths containing organic and/or inorganic acids which, owing to the concentrations used, must meet certain safety requirements and entail costly disposal procedures once the baths are depleted. Iron-absorbing products obtainable using biological methods are generally active in the neutral pH range, eliminating the salt production and contamination of the effluent associated with the neutralisation process normally required. Rust can be removed using reproducible intra- or extra-cellular products which have a high affinity with iron ions. The proposed agents are produced by culturing appropriate organisms in a suitable medium in such a way that they are stimulated to produce these agents. The articles requiring de-rusting are then treated by being dipped in or painted with the agent. Provision of appropriate supports to immobilise the articles facilitates use of the agents and permits recycling of the agent by suitable treatment.

Claims

AMENDED CLAIMS [received at the International Bureau on 12 March 1996 (12.03.96); original claims 1-10 replaced by amended claims 1-7 (1 page)] 1 . Process for de-rusting surfaces, characterized gekennzeich¬ net that storage and transport compounds of iron, which occur in the organism, are brought into contact with high affinity and binding capacity to iron with undesirable two and trivalent Eisenverbindun¬ gene, complexes, and Reakti¬ form onsprodukte and replace the iron compounds. 2. The method according to claim 1, characterized in that the storage and transport connections of iron in immobilized form are used. 3. Process according to claims 1 and 2, characterized in that the de-rusting surfaces are immersed in a bath with the storage and transport connections of the iron in concentrations of 1 g / l or more and moves the bath and the storage and Transport connections of the iron are swirled on the surface. 4. Process according to claims 1 and 2, characterized in that the storage and transport connections of the iron are applied to the surface and after a short exposure time by wiping or rinsing away again. 5. The method according to the preceding claims, characterized gekenn¬ characterized in that the spent storage and Transportverbindun¬ conditions of the iron separated by retention in a membrane separation system from the bath and the regeneration are supplied. 6. Process according to claims 1 to 5, characterized in that the liquid cultures of suitable microorganisms are added directly to the de-rusting and increased in this. 7. A process for the preparation of the compounds mentioned in claim 1, characterized in that suitable microorganisms for the production of active components in almost low-iron Nährlö¬ solution are attracted.