Abstract: The present invention relates to a multi-step process for producing HAN that is free of ammonium nitrate. The process comprises the steps of: (a) stripping ammonia from an ammonia-containing, aqueous hydroxylamine solution having a hydroxylamine concentration of at least 10% by weight based upon the weight of the hydroxylamine solution, by contacting the ammonia-containing hydroxylamine solution with a stripping agent selected from the group consisting of inert gases and steam to provide an ammonia-free, aqueous hydroxylamine solution, and (b) reacting the ammonia-free, aqueous hydroxylamine solution with aqueous nitric acid having an acid concentration of at least about 0.1%, preferably at least about 20%, based upon the weight of the aqueous nitric acid, to produce ammonium nitrate-free HAN. In another process embodiment of the invention, the above-described ammonia stripping step is not required, and the hydroxylamine concentration is at least about 0.

Abstract: The present invention relates to a multi-step process for producing HAN that is free of ammonium nitrate. The process comprises the steps of: (a) stripping ammonia from an ammonia-containing, aqueous hydroxylamine solution having a hydroxylamine concentration of at least 10% by weight based upon the weight of the hydroxylamine solution, by contacting the ammonia-containing hydroxylamine solution with a stripping agent selected from the group consisting of inert gases and steam to provide an ammonia-free, aqueous hydroxylamine solution, and (b) reacting the ammonia-free, aqueous hydroxylamine solution with aqueous nitric acid having an acid concentration of at least about 0.1%, preferably at least about 20%, based upon the weight of the aqueous nitric acid, to produce ammonium nitrate-free HAN. In another process embodiment of the invention, the above-described ammonia stripping step is not required, and the hydroxylamine concentration is at least about 0.

Abstract: A process for the removal of mercury from industrial waste streams is disclosed wherein the waste stream is a nitrate based solution that has been decomposed by the addition of hypochlorite. The method involves adding a reducing agent to reduce the hypochlorite and/or adjusting the pH by the use of a strong acid to less than about 2.0, converting any residual chlorine to a soluble unreactive salt, adding a soluble precipitating agent, such as sodium sulfide, to the solution in a ratio to the mercury present of greater than 1:1 to about 2:1 to precipitate out the mercury as a mercury compound. The solution is then filtered to remove the precipitated mercury compound.

Abstract: A method and system for treating liquid chlorine to remove inert gases therefrom. Liquid chlorine is treated by passing it through a molecular sieve having a molecular pore diameter greater than the molecular diameter of the inert gases and smaller than the molecular diameter of chlorine so that the inert gases are adsorbed by the sieve while the liquid chlorine passes therethrough. The sieve may be regenerated by heating the sieve and evacuating by vacuum, followed by a purging with a gas and then a further vacuum evacuation.

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: A process for producing dichlorine monoxide which includes: feeding an aqueous solution of hypochlorous acid containing at least 20% by weight of HOCl to a reaction vessel; maintaining the temperature of the aqueous solution of hypochlorous acid in the range of from about -10.degree. to about +40.degree. C.; passing an inert gas through the aqueous solution of hypochlorous acid to produce a gaseous mixture comprising dichlorine monoxide, chlorine and inert gas; an contacting the gaseous mixture with dry ice to provide a solid phase of dry ice and dichlorine monoxide.

Abstract: Ammonium perchlorate is produced a process which comprises:(a) oxidizing a solution of chloric acid substantially free of ionic impurities,(b) introducing gaseous ammonia or an ammonium hydroxide solution into the crystallizing zone to produce ammonium perchlorate crystals, wherein the aqueous solution of perchloric acid and/or the ammonium hydroxide solution is in droplet form.High purity ammonium perchlorate crystals can now be produced directly which are free of transition metals, sulfates and phosphates, as well as substantially free of other ionic impurities including alkali metals, chlorate and chloride.

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 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: A process for decomposing a solution of a hydroxylammonium compound includes raising the pH of the solution to about 8 or higher and reacting the alkaline solution with a source of hypohalite ions. The process decomposes solutions of hydroxylammonium salts in a manner which produces benign liquid and gas effluents which can be readily disposed of or discharged.

Abstract: A process for reducing excess nitric acid in an aqueous hydroxylamine nitrate solution. The process is conducted by reacting the aqueous hydroxylamine nitrate solution with a basic neutralizing agent such as nitric oxide, hydroxylamine vapor or a mixture thereof or by contacting the aqueous hydroxylamine nitrate solution with an anion exchange resin having a pKa in the range of from about 5 to about 9. The aqueous hydroxylamine nitrate solution may be produced by the electrolysis of nitric acid.

Abstract: Concentrated solutions of inorganic hydroxylammonium salts can safely be produced in a process for concentrating a dilute solution of an inorganic hydroxylammonium salt by contact with a membrane having a sorption side and a desorption side. The process comprises contacting the dilute solution with the sorption side of a membrane, which is substantially permeable to the solvent and substantially impermeable to the solute of the solution, to sorb the solvent and permit the solvent to flow through the membrane to the desorption side. Desorbing the solvent from the desorption side of the membrane.Highly concentrated aqueous solutions of hydroxylammonium salts which are heat sensitive are produced by the novel process of the invention which does not require directly heating the solution and is substantially free of hazards.

Abstract: A solution of hydroxylamine nitrate is electrolytically produced in an electrochemical cell having a cathode compartment, an anode compartment, and a separator between the cathode compartment and the anode compartment. The process comprises feeding a catholyte consisting essentially of an aqueous nitric acid solution to the cathode compartment. An anolyte solution is fed to the anode compartment. The catholyte is electrolyzed while maintaining the cathodic reaction temperature below about 50.degree. C. and a cathode half-cell potential at from about -0.5 to about -3 volts to produce a hydroxylamine nitrate solution which is recovered from the cathode compartment.The novel process of the present invention directly produces highly concentrated hydroxylamine nitrate solutions of high purity, i.e., suitable for use in a monopropellant.

Abstract: A process for the electrolysis of an aqueous solution of an alkali metal halide in an electrolytic cell having an anode compartment containing at least one anode, a cathode compartment containing at least one cathode, and a cation exchange membrane separating the anode compartment from the cathode compartment comprises feeding the aqueous solution of an alkali metal halide to the anode compartment; feeding an oxygen-containing gas to the cathode compartment; and electrolyzing the alkali metal halide solution to produce a halogen gas and alkali metal ions in the anode compartment. The alkali metal ions and water are passed through the cation exchange membrane into the cathode compartment to contact a hydrophilic porous cathode. The alkali metal ions, the water and the oxygen-containing gas produce a concentrated alkali metal hydroxide solution which flows through a hydrophilic porous cathode.

Abstract: An electrode for use in an electrolytic cell, wherein the electrode comprises a conductor and an element of a second metal, at least a portion of each having contact surfaces being held in intimate contact with the other, said conductor and said element each having a conductive coating applied to the contact surface, said conductive coating comprising between about 20 and about 30 percent indium and between about 80 and about 70 percent gallium, whereby the contact resistance between said conductor and said element is reduced.

Abstract: An electrode for use in an electrolytic cell, and a method for producing same, wherein said electrode comprises an internal copper conductor and an external element of a second metal, at least a portion of each having contact surfaces being held in intimate contact with the other, said conductor and said element each having a conductive coating applied to the contact surface, said conductive coating comprising between about 20 and about 30 percent indium and between about 80 and about 70 percent gallium, whereby the contact resistance between said conductor and said element is reduced.

Abstract: A process for removing chlorate ions from a recirculating anolyte brine as typically used in membrane chlor-alkali cells is disclosed. In this, a portion of the circulating brine after dechlorination and resaturation with additional alkali metal chloride is diverted and treated with a stoichiometric amount of hydrochloric acid to convert substantially all of the chlorate to chlorine gas and chloride ion. When performed in this manner, substantially lower quantities of acid are required as compared to prior art processes and the problems with the generation of ClO.sub.2 are minimized.

Abstract: A process for the production of chlorine dioxide comprises feeding an inert gas to a reaction zone and applying an electrical discharge to the inert gas to produce a high temperature plasma. Chlorine gas and oxygen gas are supplied simultaneously to the reaction zone and reacted in the plasma to produce a gaseous mixture comprised of chlorine dioxide, chlorine, oxygen and inert gas, the molar ratio of oxygen to chlorine in the reaction zone being at least about 2.5:1. The gaseous mixture is recovered from the reaction zone. Chlorine dioxide, which may be recovered as a gas or reacted to produce an alkali metal chlorite, is employed as a bleaching agent and a water treatment agent.

Abstract: A process is disclosed for substantially reducing the dissolved halogen and hypohalite ion concentration in a recycled brine from a membrane electrolytic cell with a closed loop brine system comprising the addition of a non-sulfate generating reducing agent to the brine in a less than conventional stoichiometric molar quantity in relation to each mole of available halogen and hypohalite present in the brine after the steps of dehalogenation, precipitation and pH adjustment.

Abstract: An electrode for use in an electrolytic cell, and a method for producing same, wherein said electrode comprises an internal copper conductor and an external element of a second metal, at least a portion of each having contact surfaces being held in intimate contact with the other, said conductor and said element each having a conductive coating applied to the contact surface, said conductive coating comprising between about 20 and about 30 percent indium and between about 80 and about 70 percent gallium, whereby the contact resistance between said conductor and said element is reduced.