Abstract: A method of an essentially complete elimination of remaining traces of mercury in gases, such as roaster gases containing SO2, and which have been treated in a chloride washer for removing elementary Hg,. It is characterized in that the gas is introduced to a scrubber plant where the same is washed with a washing liquid such that any content of gaseous HgCl2. The gas is absorbed by the washing liquid and is subjected to a turbulent and mechanical action in the scrubber so as to physically put together any Hg, HgCl2 and Hg2Cl2 and other compounds of Hg present in particle or drop form into bigger aggregates or agglomerates. Thus formed aggregates or agglomerates and present bigger particles are brought to be separated from the gas and then be collected and removed. The invention may be completed with further steps for the elimination of any remaining mercury.

Abstract: The invention relates to a capsule for the containment of spent nuclear fuel, wherein the capsule has a cylindrical part which comprises a steel cylinder tightly embraced by a copper layer whose thickness is of the same order as the thickness of the cylinder wall. The copper layer is a continuous layer applied electrolytically over the outer surface of the steel cylinder and has an homogenous grain structure. The invention also relates to a method of producing capsules for the containment of spent nuclear fuel, wherein a steel cylinder of predetermined length and diameter is placed as a cathode in an electrolytic cell containing a copper salt solution as electrolyte. An electric current whose strength is effective in precipitating copper is passed through the cell to the steel cylinder via one or more anodes, while rotating the cylinder, until a copper coating of predetermined thickness has been formed on the outer surface of the cylinder.

Abstract: A method for purifying aqueous solutions having varying concentrations of contaminants and/or various contaminants including ions of several metals and elements by conducting precipitation in a first precipitation stage by adding lime in a surplus quantity whereby a pH of about 12 is established and maintained in the solution and a major part of the contaminant content is precipitated so as to form a solution having a substantially constant composition and to form a precipitate that is isolated and removed together with residual lime. Precipitation is then conducted in a second precipitation stage by adding a reagent for precipitation at a pH in the range of 4-11 wherein residual contaminant in the formed solution from the first precipitation stage is precipitated the precipitate is isolated and returned to the first precipitation stage.

Abstract: The invention relates to a method of decreasing the risk of injury from mercury in conjunction with dental treatment. The invention is characterized by passing an effective air flow immediately outside the oral cavity in which the dental treatment is effected. The air flow, together with air removed by suction from the oral cavity when sucking saliva therefrom is passed through a first filter in which solid and liquid particles are extracted from the air flow. The air is then passed through a second filter which is capable of taking up essentially all of the mercury vapor present in the air. This filter is preferably a selenium filter.

Abstract: The invention relates to an emission electrode (10) for use in an electrostatic precipitator, in combination with one or more collector electrodes, wherein the emission electrode includes a carrier bar (11) and a plurality of electrode elements (12). One end-part of respective electrode elements (12) is connected to the peripheral surface of the carrier bar (11) in the absence of a gap therebetween, and in a manner such that the electrode elements will project from the peripheral surface of the carrier bar in a number of mutually different directions. The free-end or tip of respective electrode elements has a pyramidal or conical configuration (13) and the shank-part (15) of the electrode elements is advantageously screw-threaded. The end-parts of the carrier bar (11) are provided with means (16) for attachment of the emission electrode to holder devices. The inventive emission electrode is highly efficient and can be manufactured and handled in a very rational and effective manner.

Abstract: The invention relates to an arrangement in a wet electrostatic precipitator (1) intended for cleansing moisture-and-dust laden gas. The wet electrostatic precipitator (1) includes a condensing cooling arrangement (21) which is integrated with the precipitator unit (20) of the electrostatic precipitator. A plurality of emission electrodes (4) are located within the collector electrodes (5) and the collector electrodes extend through the cooling arrangement (21). Means in the form of distribution pipes (50, 60) are disposed in the upper and lower end-parts of the precipitator unit (20), in a manner such as to achieve uniform distribution of cooling medium (23) on the outer surfaces of the collector electrodes (5), the gas flowing forwardly within the collector electrodes (5).

Abstract: The present invention relates to a method for decoloring sulphuric acid produced in accordance with the contact method, comprising one or more absorption circuits. The produced sulphuric acid is decolored by adding hydrogen peroxide to the system. The method is characterized by adding the hydrogen peroxide to the sulphuric acid in the final absorption circuit, and by maintaining the temperature in this circuit above about 70.degree. C.

Abstract: The invention relates to a method for extracting dioxins and like highly toxic, organic contaminants from a gas. The invention is characterized by contacting the gas with a liquid aerosol over a pre-determined period of time, and by electrically charging the particles present in the aerosol, both solid and liquid particles, and subsequently separating the particles from the gas, preferably with the aid of a wet electrostatic precipitator.