Diaphragm for electrolytic cell
AssigneeEagle Controlled 2 Ohio Spinco, Inc.
InventorHenry Schussler
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Abstract
Describes a liquid-permeable diaphragm assembly for use in electrolytic cells, e.g., chlor-alkali electrolytic cells. The diaphragm assembly includes a foraminous cathode, a liquid permeable base mat comprising synthetic polymeric material that is at least partially resistant to the environment within the electrolytic cell on the foraminous cathode, and a topcoat of water-insoluble particulate material on the base mat. The topcoat is deposited on the base mat from an aqueous slurry comprising (i) at least one oxide, boride, carbide, nitride or silicate of a valve metal, (ii) clay mineral, (iii) hydrous metal oxide chosen from the hydrous oxides of magnesium, the hydrous oxides of zirconium, and mixtures of such hydrous metal oxides, and (iv) alkali metal polyphosphate.
Claims18
A liquid-permeable diaphragm for use in an electrolytic cell comprising:
- (a) a liquid-permeable base mat, said base mat comprising synthetic polymeric material that is at least partially resistant to the environment within said electrolytic cell, and
- (b) a coating of water-insoluble particulate material on said base mat, the water-insoluble particulate material having been deposited on said base mat from an aqueous slurry comprising:
- (i) at least one oxide, boride, carbide, nitride or silicate of a valve metal,
- (ii) clay mineral,
- (iii) hydrous metal oxide chosen from the hydrous oxides of magnesium, the hydrous oxides of zirconium, and mixtures of said hydrous metal oxides, and
- (iv) alkali metal polyphosphate.
A liquid-permeable diaphragm assembly for use in a chlor-alkali electrolytic cell comprising:
- (a) a foraminous cathode,
- (b) a liquid-permeable base mat on said foraminous cathode, said base mat comprising synthetic polymeric material that is at least partially resistant to the environment within said electrolytic cell, and
- (c) a coating of water-insoluble particulate material on said base mat, the water-insoluble particulate material having been deposited on said base mat from an aqueous slurry comprising:
- (i) at least one oxide, boride, carbide, nitride or silicate of a valve metal,
- (ii) clay mineral,
- (iii) hydrous metal oxide chosen from the hydrous oxides of magnesium, the hydrous oxides of zirconium, and mixtures of said hydrous metal oxides, and
- (iv) alkali metal polyphosphate.
In the method of electrolyzing alkali metal halide brine in an electrolytic diaphragm cell wherein the electrolytic cell comprises an anode compartment containing an anode and alkali metal halide brine, a cathode compartment, and a liquid-permeable diaphragm assembly separating the anode compartment and the cathode compartment, the improvement comprising electrolyzing alkali metal halide brine in an electrolytic diaphragm cell having a liquid-permeable diaphragm assembly comprising:
- (a) a foraminous cathode,
- (b) a liquid-permeable base mat on said foraminous cathode, said base mat comprising synthetic polymeric material that is at least partially resistant to the environment within said electrolytic cell, and
- (c) a coating of water-insoluble particulate material on said base mat, the water-insoluble particulate material having been deposited on said base mat from an aqueous slurry comprising:
- (i) at least one oxide, boride, carbide, nitride or silicate of a valve metal,
- (ii) clay mineral,
- (iii) hydrous metal oxide chosen from the hydrous oxides of magnesium, the hydrous oxides of zirconium, and mixtures of said hydrous metal oxides, and
- (iv) alkali metal polyphosphate.
Dependencies are inferred from the claim text.