US3864456A — Manufacture of chlorine dioxide, chlorine and anh…

Claim 1

Independent Claim 186 words

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

Claim 2

Dependent Claim 186 words

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

Claim 3

Dependent Claim 23 words

A process according to claim 1 wherein the acidity of said reaction solution is maintained between about 1 molar and about 2.2 molar.

Claim 4

Dependent Claim 25 words

A process according to claim 1 wherein the molar ratio of chloride to chlorate added to said reaction solution is between about 1:1 and 6:1.

Claim 5

Dependent Claim 54 words

A process according to claim 1 wherein under steady sTate conditions all of the water added to said reaction zone and formed by reaction less any water of crystallization in any solid crystalline material crystallized from said reaction solution and any other water removed other than by evaporation is evaporated in said reaction zone.

Claim 6

Dependent Claim 118 words

A continuous process for the production of chlorine dioxide, chlorine, and anhydrous sodium sulphate which comprises continuously effecting the reaction of chlorate ions, chloride ions, sulphate ions, hydrogen ions and sodium ions in an aqueous solution while maintaining the acidity of said solution at from about 1.0 to 2.4 molar, whereby chlorine and chlorine dioxide are continuously generated, said process being conducted continuously at subatmospheric pressure and at a temperature between about 30*C. and a temperature above which substantial decomposition of said chlorine dioxide would occur corresponding to the boiling point of said solution at the absolute pressure thereon, and continuously evaporating, at subatmospheric pressure, sufficient water from said solution to drystallize anhydrous sodium sulphate from said solution.

Claim 7

Dependent Claim 118 words

A continuous process for the production of chlorine dioxide, chlorine, and anhydrous sodium sulphate which comprises continuously effecting the reaction of chlorate ions, chloride ions, sulphate ions, hydrogen ions and sodium ions in an aqueous solution while maintaining the acidity of said solution at from about 1.0 to 2.4 molar, whereby chlorine and chlorine dioxide are continuously generated, said process being conducted continuously at subatmospheric pressure and at a temperature between about 30*C. and a temperature above which substantial decomposition of said chlorine dioxide would occur corresponding to the boiling point of said solution at the absolute pressure thereon, and continuously evaporating, at subatmospheric pressure, sufficient water from said solution to drystallize anhydrous sodium sulphate from said solution.

Claim 8

Dependent Claim 19 words

The process of claim 5 in which said acidity is maintained at from about 1 to about 2.2 molar.

Claim 9

Dependent Claim 176 words

In a continuous process of producing chlorine dioxide by effecting the reaction of sodium chlorate with sodium chloride and sulphuric acid in a solution contained in a vessel, the steps which comprise providing in said solution a concentration of said chloride exceeding 0.60 molar and less than 3.19 molar of said chloride and of said chlorate exceeding 2.71 molar, continuously providing an acidity in said solution from about 1 to a value less than about 2.2 molar, said vessel being maintained continuously at subatmospheric pressure, said reaction resulting in the continuous formation of chlorine, chlorine dioxide and simultaneously therewith neutral sodium sulphate, said reaction being carried out at a temperature between about 30*C. and a temperature above which substantial decomposition of said chlorine dioxide would occur corresponding to the boiling point of said solution at the absolute pressure thereon, removing said chlorine and chlorine dioxide as formed in said reaction and recovering anhydrous neutral sodium sulphate by evaporating in said vessel sufficient water from said solution to crystallize said anhydrous neutral sodium sulphate in said vessel.

Claim 10

Dependent Claim 176 words

In a continuous process of producing chlorine dioxide by effecting the reaction of sodium chlorate with sodium chloride and sulphuric acid in a solution contained in a vessel, the steps which comprise providing in said solution a concentration of said chloride exceeding 0.60 molar and less than 3.19 molar of said chloride and of said chlorate exceeding 2.71 molar, continuously providing an acidity in said solution from about 1 to a value less than about 2.2 molar, said vessel being maintained continuously at subatmospheric pressure, said reaction resulting in the continuous formation of chlorine, chlorine dioxide and simultaneously therewith neutral sodium sulphate, said reaction being carried out at a temperature between about 30*C. and a temperature above which substantial decomposition of said chlorine dioxide would occur corresponding to the boiling point of said solution at the absolute pressure thereon, removing said chlorine and chlorine dioxide as formed in said reaction and recovering anhydrous neutral sodium sulphate by evaporating in said vessel sufficient water from said solution to crystallize said anhydrous neutral sodium sulphate in said vessel.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-02-03	1978-08-05	1979-02-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-02-03	1982-08-05	1983-02-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-02-03	1986-08-05	1987-02-04	$7700.00	Window Closed / Lapsed

Manufacture of chlorine dioxide, chlorine and anhydrous sodium sulphate

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