Lenzing Aktiengesellschaft

Christian Hager

Heinrich Firgo

Johann Manner

Wolfram Kalt

Arnold Nigsch

Johann M&auml;nner

Johannes Kneissl

Franz Nussbaumer

Thomas Endl

Wolfgang Helmut Schkorwaga

Rudolf Emeder

The invention relates to a process for the reprocessing respectively purification of aqueous solutions of a tertiary amine oxide, particularly of process waters, e.g. used precipitation baths, which occur during the production of cellulosic moulded bodies, comprising the separation of turbidifying agents and solid impurities from the solution. The process in accordance with the invention is characterised in that the turbidifying agents and impurities are at least partly separated by means of a flotation process.

Method for preparing or purifying aqueous solutions of a tertiary amino-oxide

The invention is concerned with a process for the production of cellulose moulded bodies wherein a suspension of cellulose in an aqueous solution of a tertiary amine-oxide is transformed into a mouldable solution, said solution being extruded by means of a forming tool and conducted into a precipitation bath. The process is characterized in that at least part of the materials in devices and pipes for the transportation and processing of the solution, which material is in contact with the mouldable solution contains at a minimum of 90% up to a depth of at least 0,5 .mu.m, preferably more than 1 .mu.m, at least one element of the group consisting of titanium, zirconium, chromium and nickel in elementary form and/or in the form of compounds provided that the remaining of the material does not contain any of the elements of the group consisting of copper, molybdenum, tungsten or cobalt. By means of the use of certain elements and compounds according to the invention, it is possible to control the occurrence and the extent of exothermal degradation reactions in the cellulose solution.

Process for the production of cellulose moulded bodies

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Seewalchen, Austria

Christian Hager