Method for recycling zirconium tetrafluoride to form zirconia

Abstract

The invention relates to a method for converting ZrF4 into ZrO2 by thermally converting solid ZrF4 and water heated in a reactor, to form ZrO2. The initial weight ratio ZrF4 on water is especially between 1 / 5 and 1 / 500, preferably between 1 / 10 and 1 / 200, more specifically between 1 / 15 and 1 / 100, and said ratio is preferably maintained essentially throughout the conversion. The thermal conversion is carried out at a temperature which is higher than, or equal to, 300 DEG C, especially between 300 and 800 DEG C, preferably between 300 and 600 DEG C, more specifically between 350 and 450 DEG C. The invention especially relates to the recycling of the zirconium alloy stripping baths.

Description

technical field [0001] The present invention relates to a method for recycling zirconium using zirconium tetrafluoride as raw material, in particular this tetrafluoride solution obtained by the zirconium alloy décapage method. Background technique [0002] Fuel assemblies for nuclear reactors, in particular for light water nuclear reactors, generally consist of a bundle of mutually parallel fuel rods secured by a frame comprising, inter alia, longitudinal ducts and transversely positioned grilles-entretoises. [0003] The fuel rods may consist of a zirconium alloy cladding into which fuel pellets are introduced. The conduits of the frame can also consist of zirconium tubes. [0004] Manufacturing zirconium tubes from blanks requires multiple successive cold rolling operations, each followed by an annealing heat treatment. Between each cold rolling operation and subsequent heat treatment, degreasing and chemical pickling operations are carried out on the rolled tube. [00...

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Problems solved by technology

This is because, the high corrosivity of the compounds present is a difficulty, the effect of which increases with temperature

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