Method of producing pure halide salts of alkaline and/or alkaline earth metal resulting from hydrolytic treatment of halogenous organic waste material

A method of producing pure halogen salts of alkaline and/or alkaline earth metals or a mixture thereof from a liquid hydrolysate fraction resulting from a treatment of halogenous, organic waste material to decompose said halogenous, organic waste material comprising the steps of

• (I) hydrolytically heating a suspension of 1 part by weight of a halogenic, organic waste material in a comminuted state in 1-10 parts by weight of an aqueous medium in the presence of a base to a temperature ranging from 200-300° C. at a pressure sufficient to maintain the water in a liquid state for a period of time sufficient to convert substantially all the organically bound halogen present to inorganic halides, and
• (II) separating the hydrolysate obtained in step (I) into a solid hydrolysate fraction and a liquid hydrolysate fraction,
• (III) neutralizing the liquid hydrolysate with hydrohalogenic acid,
• (IV) adding a flocculent to the neutralized hydrolysate;
• (V) separating the material from step (IV) into a solid containing fraction and an aqueous solution;
• and
• (VI) nanofiltering the aqueous solution to obtain a retentate and a permeate, wherein the permeate is further treated to obtain the pure salts.