Abstract: Chlorine dioxide is generated very efficiently and safely by reducing an alkali metal chlorate with hydrochloric acid in a single generator-crystallizer in the presence of a chloropalladinate(II) complex catalyst or a mixed catalyst consisting of said chloropalladinate(II) complex catalyst and a compound or ions selected from the group consisting of vanadium pentoxide, manganese ions, dichromate ions, lead ions, and arsenic ions.

Abstract: A process for producing chlorine dioxide which comprises(1) feeding hydrochloric acid and an excess on a stoichiometric basis of sodium chlorate produced in an electrolytic cell for producing sodium chlorate into a reaction zone for producing chlorine dioxide;(2) reacting the hydrochloric acid and the sodium chlorate in the reaction zone to form a gaseous reaction product containing chlorine dioxide and chlorine and so that sodium chloride produced is precipitated to form a slurry-like residual reaction mixture containing the precipitated sodium chloride;(3) continuously removing the chlorine dioxide as the gaseous reaction product;(4) simultaneously withdrawing the slurry-like residual reaction mixture containing the precipitated sodium chloride continuously from the reaction zone;(5) feeding water to the withdrawn residual reaction mixture to dissolve the sodium chloride and form a solution containing sodium chloride;(6) blowing air or an inert gas through the solution containing sodium chloride to remove a

Abstract: Chlorine dioxide is generated very efficiently and safely by reducing a chlorate in a strong acid in the presence of a catalyst containing thallium ions together with palladium ions or silver ions.

Abstract: There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate a reducing agent, and a mineral acid are reacted in a vessel, and the salt crystals are separated from the generator crystal slurry.

Abstract: The efficiency of a low actual hydrogen ion concentration chlorine dioxide producing process in which a chlorate and hydrochloric acid or hydrogen chloride are fed to a reaction medium in a single vessel generator-evaporator crystallizer is increased by the use of small quantities of methanol.

Abstract: Chlorine dioxide is generated very efficiently and safely by reducing a chlorate in a strong acid in the presence of a complex catalyst consisting of palladium(II) and an amino acid or an alkali metal salt thereof.

Abstract: The efficiency of a low total acid normality chlorine dioxide producing process in which a chlorate, a chloride and sulphuric acid are fed to a reaction medium in a single chambered generator-evaporator-crystallizer vessel is increased by the use of small quantities of methanol.

Abstract: A method is disclosed to produce chlorine dioxide from sodium chlorate by reacting the chlorate with HCl. The method comprises forming in a reaction vessel an aqueous reaction medium containing at least about 5.5 moles per liter of the sodium chlorate, sufficient HCl to provide an acid normality of at least about 0.002, and sufficient sodium chloride to saturate the reaction medium; boiling the reaction medium at a temperature of up to about 100.degree. C; and withdrawing a mixture containing chlorine dioxide gas, chlorine gas and water vapor from the reaction vessel.

Abstract: Chlorine dioxide is manufactured by reducing an alkali metal chlorate in an acid medium by means of a gaseous or liquid reducing agent in at least one production reactor, with recycling of the tail gases to the said reactor, in order to dilute the chloride dioxide produced. In the new process, the tail gases to be recycled are brought into contact with an excess of reducing agent and a sufficient amount of water to reduce virtually all of the chlorine contained in these tail gases to hydrochloric acid, and thereafter the mixture thus obtained, of tail gases after reduction, and of reducing agent, is recycled, at least partly, to the said reactor. In this way, a large amount of chloride ions, which are immediately available for the basic reaction of production of chlorine dioxide, is introduced at the same time as the neutral gases required for dilution.

Abstract: A method of separating sulfuric acid from spent chlorine dioxide generator liquor. The method comprises simultaneously adding to the spent liquor, a water-soluble organic compound selected from the group consisting of alcohols and ketones, and water. The resulting solid is separated to leave an aqueous solution of sulfuric acid. The method is of particular application in acid and salt cake recovery from the effluent of a chlorine dioxide generator operating at an acid normality of between 6 and 11.

Abstract: Chlorine dioxide and chlorine are produced by reduction of sodium chlorate with chloride ions in an aqueous acid medium having a total acid normality of 2 to 4.8 normal. The reaction medium is maintained at its boiling point under a subatmospheric pressure to provide steam dilution of the chlorine dioxide and chlorine and anhydrous neutral sodium sulphate is deposited therefrom. Chlorine dioxide is recovered as an aqueous solution containing some dissolved chlorine while the bulk of the chlorine is recovered in gaseous form.

Abstract: Chlorine dioxide is produced in a continuous process by reaction of sodium chlorate and hydrochloric acid. The reaction medium is maintained at its boiling point under subatmospheric pressure and the resulting steam is used to dilute the chlorine dioxide and chlorine and remove the same from the reaction zone. Sodium chloride is deposited from the reaction medium in the reaction zone. The reaction medium also contains buffering anions and the actual hydrogen ion concentration of the reaction medium is maintained in the range of about 0.05 to 0.3 normal to maintain an economic production rate for the chlorine dioxide.

Abstract: The efficiency of the Solvay chlorine dioxide producing process is enhanced by the use of a high total acid normality and a single vessel generator-evaporator-crystallizer.

Abstract: An improved process is provided for the production of chlorine dioxide and chlorine wherein an alkali metal chlorate and a strong acid selected from the group sulfuric acid, hydrochloric acid, phosphoric acid, and mixtures thereof are circulated and reacted in an integral forced circulation crystallizing reaction evaporator comprising in vertical disposition:a. an upper crystallizing evaporation chamber having a substantially vertically disposed cylindrical partition which divides at least the lower portion of the reaction evaporation chamber into a first and second substantially concentric cylindrical sections;B. a heat exchange chamber, andC. a lower pump chamber, having a pump means disposed therein to provide forced circulation of fluids within the reaction evaporator.An aqueous slurry of alkali metal salt of the strong acid is withdrawn from the lower portion of the pump chamber and chlorine dioxide, chlorine, and water vapor are withdrawn from the evaporation chamber.

Abstract: Chlorine dioxide is produced in a continuous process by reaction of sodium chlorate and hydrochloric acid. The reaction medium is maintained at its boiling point under subatmospheric pressure and the resulting steam is used to dilute the chlorine dioxide and chlorine and remove the same from the reaction zone. Sodium chloride is deposited from the reaction medium in the reaction zone. The mole ratio of chlorate to chloride in the reaction medium, and the temperature of the reaction medium are controlled within narrow limits to provide high efficiency of production of chlorine dioxide.

Abstract: Chlorine dioxide is generated very efficiently and safely by reducing a chlorate in a strong acid in the presence of a complex catalyst consisting of palladium (II) and a .beta.-diketone.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and a mineral acid are reacted in a single vessel, and the resultant alkali metal salt is converted to a more desirable salt in a metathesis column by reaction with an appropriate acid or an alkaline earth or alkali metal, chloride.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and a mineral acid are reacted in a single vessel, and the resultant alkali metal salt is converted to a more desirable salt in a metathesis column by reaction with an appropriate acid or an alkaline earth or alkali metal, chloride.

Abstract: There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate, and hydrochloric acid are reacted in a vessel, and the salt crystals are separated from the generator crystal slurry.

Abstract: The present invention relates to removal of chromate from an aqueous solution of an alkali metal chlorate and chloride, particularly sodium chlorate and sodium chloride in a selected ratio which has been obtained by the electrolysis of an aqueous solution of alkali metal chloride containing chromate in which the essentially chromate free aqueous solution of alkali metal chlorate and chloride contains the chlorate and chloride in essentially the same selected ratio. In the process the chromate containing aqueous solution of alkali metal chlorate and chloride is acidified with hydrochloric acid to a pH value not smaller than 0.5 and passed through an anionic ion exchange resin bed which has previously been saturated with alkali metal chlorate and chloride. The bed is then regenerated by passing an aqueous solution of an alkali metal hydroxide and alkali metal chloride therethrough to remove chromate therefrom.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and sulfuric acid are reacted in a single vessel, and the resultant alkali metal sulfate converted to alkali metal chloride in a metathesis column by reaction with hydrochloric acid.

Abstract: A chlorine dioxide-producing process is provided in which water vapor is used to dilute and remove the chlorine dioxide produced from sodium chlorate and hydrochloric acid from the reaction vessel. A cyclic arrangement is provided in which the recycle liquid heated to the boiling point of the reaction medium in the generator is allowed to expand gradually to provide a vapor/liquid/solid mixture which is discharged at low velocity to the generator. Vibration due to boiling is considerably reduced and wear of generator walls due to impinging materials is eliminated.

Abstract: There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate, and a mineral acid are reacted in a single vessel, and the salt crystals separated from the generator crystal slurry.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and sulfuric acid are reacted in a single vessel, and the resultant alkali metal sulfate converted to alkali metal chloride in a metathesis column by reaction with hydrochloric acid.

Abstract: A process for the production of chlorine dioxide, chlorine and an inorganic salt comprising reacting an aqueous solution of a chlorate with hydrochloric acid under reduced pressure at a temperature near the boiling point of said solution, withdrawing produced chlorine dioxide, chlorine and water vapor from said solution, replenishing said solution with an additional amount of chlorate and acid, saturating said solution with a cation of said chlorate and an anion of said acid and crystallizing in said solution, a salt of the cation of the chlorate and the anion of the said acid.

Abstract: The present invention relates to removal of chromate from an aqueous solution of an alkali metal chlorate and chloride, particularly sodium chlorate and sodium chloride in a selected ratio which has been obtained by the electrolysis of an aqueous solution of alkali metal chloride containing chromate in which the essentially chromate free aqueous solution of alkali metal chlorate and chloride contains the chlorate and chloride in essentially the same selected ratio. In the process the chromate containing aqueous solution of alkali metal chlorate and chloride is acidified with hydrochloric acid to a pH value not smaller than 0.5 and passed through an anionic ion exchange resin bed which has previously been saturated with alkali metal chlorate and chloride. The bed is then regenerated by passing an aqueous solution of an alkali metal hydroxide and alkali metal chloride therethrough to remove chromate therefrom.