Abstract: The invention is directed to an improvement in operation of wash columns, and more in particular to an apparatus for separating solid particles from a slurry and to a process for separating solid particles from a mother liquor slurry. The apparatus of the invention comprises a wash column (1), which comprises a melting circuit (8,10,11,21), wherein means (22,23) are present to introduce a compound or composition to said wash column between a wash front (6b) formed in said wash column in operation and a product outlet and/or in the melting circuit.

Abstract: The invention is directed to an improvement in operation of wash columns, and more in particular to an apparatus for separating solid particles from a slurry and to a process for separating solid particles from a mother liquor slurry. The apparatus of the invention comprises a wash column (1), which comprises a melting circuit (8,10,11,21), wherein means (22,23) are present to introduce a compound or composition to said wash column between a wash front (6b) formed in said wash column in operation and a product outlet and/or in the melting circuit.

Abstract: A rotating knife is disclosed for disintegrating a crystal bed formed in a washing column for processing suspension of solid particles in a liquid. The rotating knife is provided with a spoke support. The spoke support comprises at least two spokes. The relative angle of the spokes is between approximately 20° and approximately 80°.

Abstract: Process for purifying a stream comprising phosphoric acid and a first amount of impurities, comprising: forming a slurry of phosphoric acid crystals in a water mother liquor; separating the phosphoric acid crystals from the mother liquor by filtration in a wash column comprising a filtering element, while a packed bed of crystals coming from the slurry forms near such filtering element; washing the separated phosphoric acid crystals in the wash column by bringing a washing liquid in countercurrent to the crystals in the bed up to a wash front, where the washing liquid recrystallizes, the bed being subjected to a movement in the direction of such wash front; forming a purified stream comprising phosphoric acid and a reduced amount of impurities by melting at least part of the washed crystals; and extracting the purified stream from the wash column through a product outlet of the wash column; wherein water is introduced into the wash column, between the wash front and the product outlet and/or in a melting circ

Abstract: A wash column for processing a suspension of solid particles in a liquid comprising a bed forming chamber in which a packed bed of solid particles can be formed, filtrate extraction means for extracting liquid from the suspension as to form the packed bed of solid particles in the bed forming chamber, and a suspension supply line for supplying the suspension directly to an end of the bed forming chamber, wherein the suspension supply line ends in the bed forming chamber.

Abstract: A rotating knife is disclosed for disintegrating a crystal bed formed in a washing column for processing suspension of solid particles in a liquid. The rotating knife is provided with a spoke support. The spoke support comprises at least two spokes. The relative angle of the spokes is between approximately 20° and approximately 80°.

Abstract: An optical arrangement, in particular a projection system, illumination system or beam shaping system for EUV lithography, including at least one optical element that is arranged in a beam path of the optical arrangement and that reflects radiation in the soft X-ray- or EUV wavelength range, wherein at least during operation of the optical arrangement at least one of, preferably each of, the reflective optical elements in the beam path, at least at the optical surface, has an operating temperature of approximately 30° C. or more, preferably of approximately 100° C. or more, particularly preferably of approximately 150° C. or more, and even more preferably of approximately 250° C. or more, and wherein the optical design of the at least one reflective optical element is selected such that its optical characteristics are optimised for operation at the operating temperature. Also presented is a method for providing a reflective optical element with such an optical design.

Abstract: The invention relates to a method and apparatus for processing a suspension. According to the invention, a suspension is led into a washing column in which at least one filter element is present, so that near the filtering element, a packed bed of particles forms. The bed is disintegrated under the influence of the impulse of a washing liquid, while particles from the bed are incorporated in the washing liquid.

Abstract: An optical arrangement, in particular a projection system, illumination system or beam shaping system for EUV lithography, including at least one optical element that is arranged in a beam path of the optical arrangement and that reflects radiation in the soft X-ray- or EUV wavelength range, wherein at least during operation of the optical arrangement at least one of, preferably each of, the reflective optical elements in the beam path, at least at the optical surface, has an operating temperature of approximately 30° C. or more, preferably of approximately 100° C. or more, particularly preferably of approximately 150° C. or more, and even more preferably of approximately 250° C. or more, and wherein the optical design of the at least one reflective optical element is selected such that its optical characteristics are optimised for operation at the operating temperature. Also presented is a method for providing a reflective optical element with such an optical design.

Abstract: The invention relates to a method and apparatus for processing a suspension. According to the invention, a suspension is led into a washing column in which at least one filter element is present, so that near the filtering element, a packed bed of particles forms. The bed is disintegrated under the influence of the impulse of a washing liquid, while particles from the bed are incorporated in the washing liquid.