Recytec Sa

Deco-hanulik Ag

Gesellschaft Zur Forderung Der Forschung an Der Eidgenossischen

Ct Umweltttechnik Ag

Firma Recytec Sa

Gesellschaft Zur Forderung Der Industrieorientierten

Jozef Hanulik

Jean-Francois Equey

Process for removing mercury from mercury contaminated materials

Process for the recycling of batteries, especially dry batteries

A method to decontaminate radioactively contaminated metallic objects in which the objects are contacted with a non- radioactive, aqueous solution containing acetic acid. The metallic objects are in contact with the acid continuously or successively over several hours until the acid is completely stoichiometrically depleted. The concentration of the aqueous solution containing acetic acid is preferably approximately 0.3 Mol/l. These steps are repeated until the residual contamination of the metallic objects is beneath the desired target threshold of 0.37 Bq/cm.sup.2. The radioactive metallic oxides and metallic hydroxides in the aqueous stoichiometrically depleted solution are sedimented out, and the sludge is solidified with cement and subsequently decontaminated.

Method for decontaminating radioactive metal surfaces

A method for decontaminating a radioactively contaminated metallic object. A radioactively contaminated metallic object is placed into a first bath and thus contacted with a non-radioactive, aqueous solution containing formic acid until the formic acid is completely stoichiometrically depleted thereby forming an aqueous, stoichiometrically depleted solution. The metallic object is then placed into a second bath of the same chemical composition. The non-radioactive, aqueous solution of the second bath is also preferably completely stoichiometrically depleted. The concentration of the aqueous solution containing formic acid is preferably about 0.3 Mol/l. These steps are repeated until the residual radioactivity level of the metallic object is beneath a permissible threshold level, such as 0.37 Bq/cm.sup.2. The radioactive metallic oxides and metallic hydroxides are sedimented out, and the sludge is solidified with cement and subsequently decontaminated.

Process for decontaminating radioactive metal surfaces

A method for dissolving radioactively contaminated surfaces of metal articles using a reagent of HBF.sub.4 acid with the addition of at least one oxidation agent, preferably hydrogen peroxide H.sub.2 O.sub.2, for the efficient decontamination of radioactively contaminated metal articles. An optimum mixture of this reagent was about 5% HBF.sub.4 acid with the addition of about 0.5% by volume of H.sub.2 O.sub.2. Radioactively contaminated lead plates, for example, were treated by this reagent, and the contaminated solution was used as an electrolyte without any further additive. The contaminated lead or lead oxide is deposited at the anode or cathode decontaminating the solution which may be returned to the process. If, instead of lead, the metal is copper, nickel, steel, silver or mercury or their alloys, the method for dissolving radioactively contaminated surfaces can be executed in the same way with the same reagent.

Method for dissolving radioactively contaminated surfaces from metal

Radioactively contaminated objects are placed into a borofluoric acid bath following a rough spot test and are precipitated in a measurable geometry on the cathode plates in the course of an electrolytic process, for example. In the course of the subsequent testing, the metals lying below a pre-determined maximum value of radioactive emissions are separated and supplied to the waste reclamation. The materials lying above this threshold value during the spot testing are first decontaminated and then placed in the acid bath. The borofluoric acid is not used up in this process and remains in the system. It is possible to use already radioactively contaminated boric acid from pressurized water reactors, to which it is merely required to add fluoric acid and to distill, for generating borofluoric acid. The method in accordance with the invention reduces the radioactive waste and reduces the testing and administrative effort required for the release of the non-radioactive materials.

Method for testing the radioactivity of objects containing metal or

Process for recycling an unsorted mixture of spent button cells and recovering their metallic components, comprising an anodic dissolution of the button cells, wherein metals constituting these cells are dissolved and redeposited at one or more cathodes, wherein metallic oxides are deposited in the anodic chamber and waste products (plastic, paper, etc.) accumulate in an anodic basket. Oxides are reduced to metals by thermal decomposition, mercury is recovered by distillation and the other metals are recovered by electrolytic separation.

Process for recycling an unsorted mixture of spent button cells and/or

The process for the electrochemical separation of metal mixtures and metal alloys comprises the steps of dissolving the starting material in an elecrolyte, substituting the metals dissolved in the electrolytic solution in succession in accordance with their electrochemical potential by electrochemically less noble metals in each case and depositing them. The electrolytic solution containing the dissolved metals is passed continuously through several cells, connected to each other, in which the electrolytic solution is brought into contact with said less noble metals. Several of the metals dissolved can be substituted simultaneously by one or more electrochemically less noble metals. Metals that are deposited simultaneously together are separated electrolytically from each other, and metals which have again gone into solution are again substituted outside the electrolysis cells by said less noble metals and deposited.

Process for the electrochemical separation of metal mixtures and metal

Contaminated surface layers are decontaminated by treatment with an aqueous fluorine base-containing decontamination solution. The aqueous decontamination solution contains 0.05 to 50 Mol of decontamination agent per liter, and the decontamination agent preferably comprises at least one substance from the group colon hexafluorosilicate acid, fluoroboric acid, and the salts of both of these. The decontamination solution produces the required high decontamination factors on metallic substances and brickworks as well. The used decontamination solution can, after regeneration, be recycled into the decontamination process. Release of decontaminated material by dissolution of the surface layer of the decontaminated objects provides decontamination of objects having complicated and hard-to-measure geometries. The decontamination agent (HBF.sub.4 -acid) is advantageously produced from contaminated boric acid from pressurized water reactor wastes by reaction with fluoride or hydrofluoric acid. The HBF.sub.4 -acid thus produced is, through distillation, separated from the contaminants and impurities.

Process for decontaminating radioactively contaminated metal or

Contaminated surface layers are decontaminated by treatment with an aqueous fluorine base-containing decontamination solution. The aqueous decontamination solution contains 0.05 to 50 Mol of decontamination agent per liter, and the decontamination agent preferably at least one substance from the group: hexafluorosilicate acid, fluoroboric acid, and the salts of both of these. The decontamination solution produces the required high decontamination factors on pressurized water reactors, boiling water reactors, metallic substances, high temperature alloys and brickworks as well. The used decontamination solution can, after regeneration, by recycled into the decontamination process. Release of decontaminated material by dissolution of the surface layer of the decontaminated objects provides decontamination of objects having complicated and hard-to-measure geometries. The decontamination agent (NBF.sub.4 -acid) is advantageously produced from contaminated boric acid from pressurized water reactor wastes by reaction with fluoride or hydrofluoric acid. The HBF.sub.4 -acid thus produced is, through distillation, separated from the contaminants and impurities.

Process for the processing of contaminated boric acid

For the recycling of electrical batteries, in particular of a mixture of high-power batteries for equipment of any chemical composition, and also of assembled printed circuit boards and electronic components, a pyrolysis of the unsorted mixture is carried out at a temperature between 450.degree. and 650.degree. C., then an electrolysis of the pyrolysis slag is carried out and subsequently a separation of the electrolysis products and removal of the products accumulating at the electrodes is carried out. In this process, which is economically profitable, no environment-polluting residues are produced and an initial sorting of material becomes unnecessary.

Process for the recycling of electrical batteries, assembled printed

To recycle fluorescent and television tubes, the latter are introduced into a container which can be sealed in a gas-tight manner and crushed under water. In this process, the ascending gases released are drawn off under suction and fed in a compressed state to the reuse process, acid which dissolves or strips off the pollutants being added to the broken glass, which is coated with pollutants, the dissolved and stripped-off pollutants are flushed out of the broken glass, the metallic constituents are removed therefrom and then the broken glass is passed to the further utilization process. A precipitating agent is added to the liquid phase and the liquid phase is then filtered, the yttrium-containing filter cake being delivered to lanthanide manufacturers for further processing. The filtrate is fed back to the container in which the tubes are crushed.

Process for recycling fluorescent and television tubes

A solution is provided for decontaminating steel surfaces, especially in nuclear reactor cooler circuits. The solution contains formic acid and/or acetic acid and at least one reducing agent such as formaldehyde and/or acetaldehyde. The solution is effective to dissolve the iron oxide from the contaminated steel surface directly and/or reductively and to convert it to Fe-(II)-formate or acetate which are stabilized by the reducing conditions in the solution. For waste disposal the dissolved iron is precipitated from the used decontaminating solution, wherein the iron compounds that have been formed are the sole adsorbents for the radioactive materials contained in the decontaminating solution.

Process for the decontamination of steel surfaces and disposal of

A sample-taking appliance comprises several sensors (61, 62, 63, 64) arranged on a turntable like sensor carrier (50) in such a manner that the application areas (68) of the small sensor sponges (67) decrease stepwise from the first to the last sensor. By simple rotation of the turntable the sensors (61, 62, 63, 64) can be brought successively into a working position. The sensor carrier (50) is preferably accommodated in a housing (25) which is open at the bottom and which is raisable and lowerable in the frame (5) of the appliance by, for example, a threaded spindle (41, 42). The threaded spindle (41) is driven by an electric motor (44). For each sampling the sensor carrier (50) is lowered until the cell voltage corresponds to a predetermined desired value. This produces sufficiently precise and reproductible measured values of the electrolytic current for ascertaining the removed layer thickness. The appliance makes it possible to take material samples even from locations of high radiation loading. The material layers removed as samples lie concentrically above each other so that the graduation of the application areas (68) comes into full effect and the material samples taken by the small sponges and the radioactivity contained therein are not falsified.

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Zurich, Switzerland

Jozef Hanulik