Abstract: An improved method and apparatus for adjusting the space between an adjustable anode and a cathode in an electrolytic cell wherein current measurements and voltage measurements are obtained for conductors to the anode sets and compared with predetermined standards for the same conductors and anode sets. Measurement of deviation from the predetermined standards are used to determine the direction of anode adjustment. A digital computer operably connected to motor drive means adapted to raise or lower anode sets upon appropriate electric signals from the computer is a preferred embodiment of this invention.

Abstract: A method and an apparatus for controlled, low current start-up of one of an electrical series of membrane electrolytic cells in which the currents through all but one of the remaining cells of the electrical series are unaffected. The method involves placing the cell to be started-up in electrical series with a variable resistor and placing the cell and resistor combination in parallel with the following or preceding one of the remaining cells in the electrical series and then slowly decreasing the resistance of the variable resistor over a preset time period so as to gradually increase the current to the cell being started up and finally eliminating the variable resistance altogether and reconnecting the cell being started-up in electrical series with the remaining cells.

Abstract: An improved process is described for the electrodeposition of both a low overvoltage metal and a sacrificial metal onto an electrically conductive substrate. The sacrificial metal is later removed by leaching the electrodeposited substrate with alkali metal hydroxide. The improvement comprises adding a sacrificial metal to the electroplating solution after electrodeposition is initiated. The amount of electric current supplied to the electroplating solution during electrodeposition may be increased or decreased over time intervals to increase the surface area and the electrochemical activity of the electroplated substrate.

Abstract: Sections of synthetic materials, such as thermoplastic materials, suitable for use in electrolytic cells for the production of chlorine and sodium hydroxide, are joined together in a reinforced liquid-tight seam by a method which comprises positioning sections of material to be joined adjacent to but spaced apart from each other, to form a gap between the sections, placing a thermoplastic sealing composition in the gap, sewing the sections of synthetic material and the thermoplastic sealing composition together to form a seam, heating the seam to a temperature sufficient to melt the thermoplastic sealing composition without melting the synthetic material or the thread thereby allowing the melted thermoplastic sealing composition to flow to and fill perforations in the synthetic material adjacent to the thread. The seam is then cooled to solidify the thermoplastic sealing composition and to form a reinforced liquid-tight seam between the sections of synthetic material.

Abstract: A process for the preparation of an alkali metal hydroxide and halogen from an alkali metal halide in a plurality of electrolytic cells, wherein each electrolytic cell is physically arranged in series with respect to the other electrolytic cells, the series having a first electrolytic cell and a last electrolytic cell, so that for a selected cell in the series, after the first electrolytic cell, catholyte alkali metal hydroxide from the catholyte chamber of a previous electrolytic cell is conveyed to the catholyte chamber of the selected electrolytic cell. The concentration of the alkali metal hydroxide is progressively increased toward a desired final concentration in the last cell through the series of electrolytic cells. Each electrolytic cell has an anolyte chamber containing an anode and a catholyte chamber containing a cathode, separated by a permselective membrane.

Abstract: An improved cathode with a conductive metal core and a Raney-type catalytic surface predominantly derived from an adherent NiAl.sub.3 crystalline precursory outer portion of the metal core is disclosed. The precursory outer portion preferably has molybdenum added to give a precursor alloy having the formula Ni.sub.x Mo.sub.1-x Al.sub.3 where x is within the range of from about 5 to about 15 weight percent. Also disclosed is a method of producing a low overvoltage cathode. The method includes the steps of taking a Ni-Mo core or substrate having about 5-20 weight percentage of Mo and coating it with aluminum then heat treating to form a Ni-Mo-Al alloy with mostly NaAl.sub.3 structure and then leaching out the Al to produce a Raney surface.

Abstract: Textile fabrics are bleached in a process which comprises contacting the textiles with an aqueous solution of dibasic magnesium hypoclorite. The bleaching solution is maintained at a pH of from about 3 to about 8 by the addition of an acid or acid salt.

Abstract: Concentrated slurries of cyanuric acid are produced in a process which comprises feeding urea to a hot solvent. In the hot solvent, the urea is pyrolyzed to produce a reaction mixture of cyanuric acid particles in the solvent. Agitation of the reaction mixture forms a suspension of cyanuric acid particles. At cyanuric acid concentrations of from about 20 to about 50 percent by weight, the cyanuric acid particles are settled from the suspension to produce a concentrated slurry phase and a supernatent solvent phase. The concentrated slurry phase is then separated from the solvent phase.The process produces concentrated cyanuric acid slurries which minimize the complexity and cost of solvent recovery, reduces energy requirements for heating the reaction mixture and recovering the solvent, and maximizes heat transfer efficiency during the pyrolysis reaction.

Abstract: A continuous process is disclosed for the production of monoalkali metal cyanurates. In the process, cyanuric acid and an aqueous solution of the alkali metal hydroxide are continuously reacted in a first reactor to produce a first slurry comprised of cyanuric acid and a monoalkali metal cyanurate. This first slurry is conveyed to a second reactor to further react the cyanuric acid with the alkali metal hydroxide to produce a second slurry comprised of the monalkali metal cyanurate.The novel process produces slurries of monoalkali metal cyanurate which are consistent both with respect to chemical composition and solids content while reducing equipment and operating costs.

Abstract: A method is presented for recovering mercury from mercury-containing liquids in which the liquids are contacted with particles of metallic silver. The method produces highly purified liquids which may be employed in applications having a low mercury tolerance such as the production of food or drug products.

Abstract: A process for cooling and drying wet chlorine gas with concentrated sulfuric acid in which in the final drying stage the acid is maintained at a temperature which cools the chlorine gas to its compression temperature.The process produces a cool, very dry chlorine gas, is energy efficient and permits optimum design of the chlorine compressor to reduce capital expense requirements.

Abstract: Disposal of effluent solutions containing sodium sulfate in an ecologically safe and economically sound manner is accomplished in a process which admixes the effluent with the aqueous solution used as the mining solution in salt deposits. The effluent-containing mining solution is injected into the brine well to dissolve sodium chloride while inhibiting the dissolution of soluble calcium compounds. Brine recovered from the wells has a reduced concentration of dissolved calcium.

Abstract: A process is provided for solvent recovery from a hot gaseous mixture comprised of ammonia, carbon dioxide, cyanuric acid particles, and solvent vapors. The process comprises scrubbing the hot gaseous mixture with a liquid solvent to remove the cyanuric acid particles and to form a scrubbed gaseous mixture. The scrubbed gaseous mixture is cooled to form condensed liquid solvent and a cooled gaseous mixture containing traces of the solvent. The temperature of the cooled gaseous mixture is kept above that at which ammonium carbamate is formed by the reaction of ammonia with carbon dioxide. Condensed liquid solvent is separated from the cooled gaseous mixture and the cooled gaseous mixture is contacted with additional liquid solvent to form a substantially solvent-free gaseous mixture.

Abstract: A process for the production of polychloroisocyanuric acids in which a depressant is added to the reaction mixture. The polychloroisocyanuric acid particles produced have improved filterability and the formation of foam during the reaction is greatly reduced. Depressants employed are alkali metal salts of alkyl esters or sulfonated alkyl esters of dicarboxylic acids or ethylene oxide terminated alkoxylated alcohols having a cloud point of up to about 50.degree. C.

Abstract: A process for producing cyanuric acid by pyrolyzing urea in a solvent in a closed reactor having interior surfaces exposed to a gas zone, the improvement which comprises contacting the interior surfaces of the closed reactor with solvent in the presence of heat to inhibit the formation of solid deposits on the interior reactor surfaces.The process maintains high rates of heat transfer during the reaction period and reduces the frequency and cost of reactor cleaning.

Abstract: Separator materials suitable for use in electrolytic cells, for example, for the electrolysis of alkali metal chloride brines, are sealed by a method which comprises coating the sections to be sealed with a synthetic thermoplastic sealing agent and ultrasonically sealing the coated portions.The method permits the sealing-in-place of separator materials and allows them to be unsealed and resealed without damage to the separators.

Abstract: An improved cation-exchange membrane for use in electrolytic processes which is comprised of a film of a perfluorosulfonic acid resin having a fluoroalkyl resin coating. The improved membrane is produced by applying an uncured fluoroalkyl resin in liquid form to a surface of the film and curing the fluoroalkyl resin to provide a solid coating on the surface of the film. The improved membrane provides efficient ion separation properties at reduced costs for energy.

Abstract: A process is described for the purification and recovery of cyanuric acid from a hot slurry of cyanuric acid in an organic solvent. In the process, the hot slurry is quenched in a quench liquid which is at a temperature for cooling the hot slurry to form a cooled slurry of cyanuric acid particles in a mixture of the solvent and the quench liquid. Cyanuric acid particles are separated from the mixture of solvent and quench liquid and recovered.The process effectively cools and separates cyanuric acid from the solvent and any color bodies present to produce a pure white crystalline product.

Abstract: A diaphragm for use in the electrolysis of alkali metal chloride brines in electrolytic diaphragm cells is comprised of a support fabric impregnated with a mixture of a non-fibrous component containing silica and glass fibers. The diaphragms are physically and chemically stable and have increased operational life.

Abstract: A diagraphm for use in the electrolysis of aqueous solutions of ionizable compounds in electrolytic diaphragm cells is comprised of a support fabric impregnated with particles of a siliceous composition having the formula:(X).sub.m (Si).sub.p (O).sub.q (H).sub.r .multidot.nH.sub.2 OwhereinX is at least one metal selected from the group consisting of Be, Mg, Ca, Sr, Ba, Ti, Zr, Al, Zn and mixtures thereof;p is a number from 1 to about 16;m is zero to about p;q is a number from 2 to about 5p+r;r is zero to about 4p; andn is zero to about 30.The siliceous compositions are capable of undergoing hydration when in contact with at least one of the ionizable compounds in the electrolytic cell.The diaphragms are physically and chemically stable, provide reduced cell voltages during operation of the cell and have increased operational life.