Abstract: An electrochemical apparatus for analyzing the zinc concentration in an aqueous zinc-halogen electrolyte is disclosed. The electrochemical apparatus includes a working electrode and an auxiliary electrode both in contact with the electrolyte to be analyzed, a reference electrode in contact with an aqueous zinc-halogen electrolyte of a predetermined concentration, and means for permitting the electrolyte to be analyzed to contact the electrolyte of predetermined concentration. The apparatus also includes circuit means for applying electrical power to the working and auxiliary electrodes for a first predetermined time period sufficient to deposit zinc metal onto the working electrode, and for measuring a potential difference across the reference and working electrodes indicative of the concentration of the electrolyte to be analyzed during a second predetermined time period.

Abstract: An electrolytic cell for separating chlorine gas from other (foreign) gases, having an anode, a cathode assembly, an aqueous electrolyte, a housing, and a constant voltage power supply. The cathode assembly is generally comprised of a dense graphite electrode having a winding channel formed in the face opposing the anode, a gas impermeable (but liquid permeable) membrane sealed into the side of the cathode electrode over the channel, and a packing of graphite particles contained in the channel of the cathode electrode. The housing separates and parallelly aligns the anode and cathode assembly, and provides a hermetic seal for the cell. In operation, a stream of chlorine and foreign gases enters the cell at the beginning of the cathode electrode channel. The chlorine gas is dissolved into the electrolyte and electrochemically reduced into chloride ions. The chloride ions disfuse through the gas impermeable membrane, and are electrochemically oxidized at the anode into purified chlorine gas.