Abstract: A process for the production of concentrated and highly purified hydroxylammonium nitrate is disclosed whereby diluted nitric acid is added to a solution containing excess aqueous hydroxylamine while the resultant mixture is cooled and agitated to obtain uniform mixing to avoid locally high concentrations of nitric acid. The mixed solution is maintained at a temperature of less than about 60.degree. Centigrade.

Abstract: An electrochemical cell is disclosed having a cell bottom or baseplate that has at least one drain hole therein which is fed by drain canals adjacent an end of the catholyte chamber such that the drain holes are gradually inclined to increase in depth laterally downwardly from the opposing sides of the cell toward the center and longitudinally downwardly from the opposing end of the cell toward the drain hole to permit removal or the addition of the liquid metal cathode from the angled electrolytic cell without requiring disassembly of the cell.

Abstract: A particular side frame design for use in an electromechanical cell with a catholyte flow pattern is disclosed wherein the cell is angled from the horizontal and the catholyte is fed into a gap in the cathode compartment between the liquid metal cathode and the membrane on the lower first end and exits the gap on the opposing higher second outlet end. The side frame is obliquely angled on the interior of the cell to prevent the escape of the flowable liquid metal cathode and to prevent contact of the acidic catholyte with the cell bottom.

Abstract: A particular side frame design for use in an electrochemical cell with a catholyte flow pattern is disclosed wherein the cell can be generally horizontal or angled slightly from the horizontal and the catholyte is fed through a transition area into a gap in the catholyte compartment between the liquid metal cathode and the membrane on a first end and exits the gap on an opposing second outlet end. The side frame has opposing sides that are obliquely and downwardly angled in the corners to support the membrane in a wrinkle free manner so that the membrane is obliquely positioned between the liquid metal cathode and the anode. The membrane is above the level of the catholyte where the catholyte enters and exits the catholyte compartment, but drops to a level below the entry and exit points.

Abstract: In a backup mode of operation a process control program sends messages, via a local area network, to a process control program running in an active mode for the purpose of obtaining current values of process control data and configuration information. If the active process control program fails to respond to an interrogation by the backup process control program the backup program automatically activates itself to assume the active role. The activation procedure includes a sequence that transmits a control pulse of predetermined width on a line of an associated process control bus to a novel digital data switch. The receipt of a valid control pulse causes the digital data switch to allow access by the backup (now active) data processor to process control I/O unit(s) while simultaneously isolating the active (now backup) data processor from the I/O units.

Abstract: A process for electrochemically treating an aqueous solution containing inorganic oxyhalide species is disclosed in which the aqueous solution is fed into the catholyte compartment of an electrochemical reduction cell using a high surface area cathode separated from an anolyte compartment to electrochemically reduce substantially all of the oxyhalide species to halide ions and produce a purified water product.

Abstract: A process which comprises heating a reaction mixture comprised of an aqueous solution containing perchlorate ions, chlorate ions and hydrogen ions to produce chlorine dioxide and oxygen gas.The novel process of the present invention provides a commercially viable process for producing chlorine dioxide from mixtures of oxy-chlorine species in the absence of a reducing agent. The process can be operated without producing an acidic salt by-product while producing a chlorine dioxide product which is substantially free of chlorine. In addition, the process of the invention permits a reduction in the amount of acid fed to the chlorine dioxide generator.

Abstract: An electrolytic filter press membrane cell and a method of operating the cell to produce concentrated perchloric acid are disclosed. The cell employs concentrated hypochlorous acid as the anolyte and operates with a two-stage single oxidation process at high current density.

Abstract: An electrochemical process and electrolytic cell for manufacturing chlorine-free chlorine dioxide from dilute alkali metal chlorite solutions in a single step is disclosed. The electrolytic cell uses a porous flow-through anode and a cathode separated by a suitable separator.

Abstract: A process for producing chloric acid in an electrolytic cell having an anode and a cathode which includes feeding an aqueous solution of hypochlorous acid to the electrolytic cell, and electrolyzing the aqueous solution of hypochlorous solution to produce a chloric acid solution. Using the process of the invention, chloric acid can be produced efficiently at substantially reduced production costs using a process which can be operated commercially. In addition, the chloric acid solutions produced are of high purity and are stable at ambient conditions.

Abstract: A process for electrolytically producing an aqueous solution of chlorine dioxide in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment, the process comprising feeding an aqueous solution of an alkali metal chlorite to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chlorine dioxide, and passing alkali metal ions from the ion exchange compartment into the cathode compartment.

Abstract: A process for electrolytically producing an aqueous solution of chlorine dioxide in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment, the process comprising feeding an aqueous solution of an alkali metal chlorite to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chlorine dioxide, and passing alkali metal ions from the ion exchange compartment into the cathode compartment.

Abstract: A process for producing chlorine dioxide by oxidizing a hypochlorous acid solution to produce a chloric acid solution, and, electrolyzing the chloric acid solution to produce chlorine dioxide.The novel process of the present invention provides a commercially viable process for producing the chloric acid and eliminates the formation of an acidic salt solution in the production of chlorine dioxide which requires disposal. Further, the process permits a reduction in the amount of acid required in the generation of chlorine dioxide.

Abstract: An electrochemical process and electrolytic cell for manufacturing chlorine-free chlorine dioxide from a dilute alkali metal chlorite solution in a single step is disclosed. The electrolytic cell uses a porous flow-through anode and a cathode separated by a suitable separator. The alkali metal chlorite solution has a conductive salt additive.

Abstract: A process for electrolytically producing an aqueous solution of chloric acid and alkali metal chlorate in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment. The process includes the steps of feeding an aqueous solution of an alkali metal chlorate to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chloric acid and alkali metal chlorate, and passing alkali metal ions from the ion exchange compartment into the cathode compartment.

Abstract: An electrolytic filter press membrane cell and a method of operating the cell are disclosed to produce concentrated chloric acid. The cell employs concentrated hypochlorous acid as the anolyte and operates at high current density. The anode structure employs a high surface area to volume ratio structure that is thin and minimizes anolyte residence time in the cell.

Abstract: An electrochemical process and electrolytic cell for manufacturing chlorine-free chlorine dioxide from dilute alkali metal chlorite solutions in a single step is disclosed. The electrolytic cell uses a porous flow-through anode and a cathode separated by a suitable separator.

Abstract: A process for electrolyzing an aqueous catholyte solution comprising an alkali meal bisulfite to produce an alkali metal hydrosulfite in an electrolytic membrane cell having a cation exchange membrane separating a cathode compartment from an anode compartment, a porous cathode having a face adjacent the membrane, a back opposite, and a porous structure conjoining the face and the back, and a cathode-membrane gap between the porous cathode and the cation exchange membrane. The process comprises directing at least 50 percent of the volume of the aqueous alkali metal bisulfite catholyte through the porous cathode and transverse to the face and back of the cathode, the porous cathode having a ratio of total surface area to the projected surface area of at least about 30:1.High purity solutions of alkali metal hydrosulfites, such as sodium hydrosulfite having concentrations of at least 120 grams per liter, are produced at current densities in the range of 1.0 to 4.5 KA/m.sup.2 and at reduced cell voltages.

Abstract: An easily transportable electrolytic cell and associated processing apparatus is modularly constructed and supported in modular support sections that are easily separated and loaded onto transport vehicles for transport to distant remote sites where the electrolytic cell module and the processing apparatus module are reassembled and the apparatus is put into operation where the product chemical produced by the electrolytic cell is utilized.

Abstract: A process control system for a filter press membrane electrochemical cell is provided that utilizes a microcomputer for multi-tasking functions to concurrently execute four programs to control the cell operation and self-correct out-of-tolerance conditions or shut cell operation down if not corrected within the allotted time period. A core process control program intercommunicates with a timer program, an alarm monitoring program and at least one sequence program in the process control system.