Method of manufacture of a diaphragm to an electrolysis cell, by drying and compacting of a felt of asbestos

摘要

A process for the production of an asbestos diaphragm for an electrolytic cell comprises forming a felt comprising asbestos fibres, treating the asbestos fibres with a solution containing alkali metal ions either before or after formation of the felt, drying and compacting the felt by passing through it a current of air, and heating the felt, characterised in that a current of warm air, preferably at 30-110 DEG C, e.g. 50 DEG C, is used for drying and compacting the felt. The felt may be formed on a foraminate support, which may be a metal cathode of an electrolytic cell, or an electrically non-conducting lattice which is applied over the cathode, or on a perforated drum or endless perforated strip or a filter according to papermaking techniques.