Process for the electrochemical production of ammonium polysulfide

US5637206A · kind A · utility

Assignee

• Metallgesellschaft AG · DE

Inventors

• Nikola Anastasijevic · Schongau, DE
• Eilhard Hillrichs · Büdingen, DE
• Karl Lohrberg · Heusenstamm, DE
• Gert Ungar · Frankfurt am Main, DE

Key dates

• Filing date: Feb 14, 1996
• Grant date: Jun 10, 1997
• Expiry date: Feb 14, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01C1/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The ammonium polysulfide is produced in at least one electrochemical cell, to which an aqueous ammonium sulfide solution is supplied as electrolyte. The cell comprises an anode, a gas diffusion cathode, and between the anode and the cathode an electrolyte chamber, where the cell voltage is 0.01 to 5V. The cathode has an electrically conductive, gas-permeable carbon layer, over which flows gas containing free oxygen, and which is in contact with the electrolyte. O.sub.2 -containing gas is introduced into the electrolyte chamber, thereby forming hydroperoxide anions (OOH.sup.-) in the electrolyte chamber. From the electrolyte chamber a solution containing ammonium polysulfide and a residual gas are withdrawn.