| 摘要 |
An asbestos diaphragm in a chlorine-alkali electrolytic diaphragm brine cell is rejuvenated to restore its liquid permeability by contacting it with an aqueous solution of an acid having an ionization constant greater than 10-5 until the solution passed through the diaphragm has a pH less than 8. As described the cell comprises vertical graphite blades secured in the cell bottom between which pass flattened tubular steel mesh cathode members connected to each other at their ends and to end half cathodes by steel mesh, thus forming a single cathode structure, and asbestos is deposited on the cathode to form a porous diaphragm dividing the cell into separate anolyte and catholyte compartments. After prolonged use, the brine is drained from the catholyte compartment of the cell and acid is introduced into the anolyte compartment and withdrawn from the catholyte compartment. The acid employed may be acetic, formic, sulphuric, phosphoric or phosphorous acid but preferably is hydrochloric acid. To prevent attack of the steel cathode the acid solution may include corrosion inhibitors such as aliphatic or heterocyclic amines, alkanolamines, aldehydes, chromates, glycerine, sugar or molasses.ALSO:An asbestos diaphragm in a chlorine-alkali electrolytic diaphragm brine cell is rejuvenated to restore its liquid permeability by contacting it with an aqueous solution of an acid having an ionization constant greater than 10-5 until the solution passed through the diaphragm has a pH less than 8. As described the cell comprises vertical graphite blades secured in the cell bottom between which pass flattened tubular steel mesh cathode members connected to each other at their ends and to end half cathodes by steel mesh, thus forming a single cathode structure, and asbestos is deposited on the cathode to form a porous diaphragm dividing the cell into separate anolyte and catholyte compartments. After prolonged use, the brine is drained from the catholyte compartment of the cell and acid is introduced into the anolyte compartment and withdrawn from the catholyte compartment. The acid employed may be acetic, formic, sulphuric, phosphoric or phosphorous acid but preferably is hydrochloric acid. To prevent attack of the steel cathode the acid solution may include corrosion inhibitors such as aliphatic or heterocyclic amines, alkanolamines, aldehydes, chromates, glycerine, sugar or molasses. |
