Method for conditioning soda effluents in the form of nepheline

摘要

This invention relates to a method for conditioning a waste constituted of an aqueous solution of sodium hydroxide NaOH of 3 to 10 M, possibly radioactive. The method is as follows: a) a metakaolin powder is added to the aqueous solution such that a suspension is obtained capable of solidifying and forming a crystalline phase of the zeolite A type; b) the suspension is introduced into a mould; c) the suspension is left to solidify in the mould in order to obtain a moulded solid product based on zeolite A; d) the moulded product is dried; and e) the zeolite A phase is converted into a nepheline type phase by heat treatment at a temperature of 1000° C. to 1500° C.