Degussa Aktiengesellschaft

Karl-Ludwig Weber

Klaus Hentschel

Marcel Vingerhoets

Marc Samson

The invention relates to aqueous solutions of sodium salts of trimercapto-s-triazine whose molar saturation concentration at 0.degree. C. to 40.degree. C. is above the saturation concentration of trimercapto-s-triazine trisodium salt (TMT-Na.sub.3). More than two but less than three hydrogen atoms of the trimercapto-s-triazine are replaced by sodium ions. The solutions preferably contain trimercapto-s-triazine disodium salt (TMT-Na.sub.2) in addition to a little TMT-Na.sub.3. Surprisingly, the water solubility of TMT-Na.sub.2 is greater than that of TMT-Na.sub.3. The solutions represent a suitable supply form for the active substance trimercapto-s-triazine (TMT-H.sub.3) used in the separation of heavy metals The preparation takes place by means of reacting TMT-Na.sub.3 with TMT-H.sub.3 in a molar ratio of 1:greater than 0-less than 0.5, especially 1:0.1 to 1:&lt;0.5 in aqueous solution.

Aqueous solutions of sodium salts of trimercapto-s-triazine, their

The disodium salt of trimercapto-s-triazine hexahydrate (TMT-Na.sub.2.6H.sub.2 O) which has a considerably higher water solubility than previously known TMT sodium salts. It is used for separating heavy metals from aqueous phase, especially from waste water. TMT-Na.sub.2.6H.sub.2 O is prepared by reacting TMT-Na.sub.3 .9H.sub.2 O, available from cyanuric chloride, with trimercapto-s-triazine (TMT-Ha.sub.3) in a molar ratio of 2-2.1 to 1 in aqueous medium with subsequent crystallization of the TMT-Na.sub.2 .6H.sub.2 O.

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Kapellen, Belgium

Karl-Ludwig Weber