Abstract: A novel continuous process and system are provided for the production of chlorine dioxide at favorable economics and high efficiency. The process involves effecting electrolysis of an aqueous solution of alkali metal chloride, in an electrolysis zone, to form an aqueous solution of alkali metal chlorate having a chlorate ion concentration of about 400 to about 1,200 g/L, and a chloride ion concentration of about 90 to about 120 g/L, gaseous hydrogen and water vapor. Hydrogen is conducted to a hydrogen chloride synthesis system where it reacts with chlorine gas, (recycled, as well as make-up,) to yield hydrogen chloride gas which is quenched with water to provide hydrochloric acid. A solution of alkali metal chlorate is conducted from the electrolysis zone to the chlorine dioxide generating zone.

Abstract: A novel electrolytic system, especially suitable for chlorate manufacture, is provided constituted by a novel electrolyzer and a novel reactor. The electrolyzer is designed for multicell assembly employing sheet metal electrodes and includes construction specially designed to hold the electrodes in place and to minimize internal liquor overflow within the cells. Electrolyte flow from cell to adjacent cell is in one direction only, and electrolyte product flow from cell to adjacent cell is in the opposite direction only. The flooded reactor provides suitable electrolyte retention time, temperature and product composition control, respectively, as well as gas separation with liquor level controlled for flooded electrolyzer system. A pipe riser is employed with liquor interconnection means to cause flow between the electrolyzer and the reactor.

Abstract: A novel anode unit is provided for a diaphragm cell. The anode unit comprises a generally rectangular parallelepiped framework including a pair of spaced-apart grid-like structurally rigid peripheral outer side walls; an ionically conductive gas impermeable membrane secured against the inner face of each such outer peripheral walls; an anode sealingly disposed between the membranes to provide a pair of fluid-tight anode compartments; means for feeding anolyte to the anode compartments; and means for withdrawing spent anolyte and entrained and/or occluded gaseous products of electrolysis therein from the anode unit. Novel diaphragm electrolytic cells including such anode units are also provided.

Abstract: A novel electrolytic system, especially suitable for chlorate manufacture, is provided constituted by a novel electrolyzer and a novel reactor. The novel separate electrolyzer is designed for multicell assembly employing sheet metal electrodes and includes novel internal construction specially designed to hold the electrodes in place and to minimize internal liquor overflow between adjacent cells. The novel reactor provides suitable electrolyte retention time, temperature and product composition control respectively as well as gas separation with liquor level controlled for flooded electrolyzer system. The electrolyzer and the reactor are connected by liquor interconnection means.