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US 5,397,557 AGranted
Tetrathiocarbonate batch process
AssigneeUnion Oil Company of California
InventorsMarjorie M. Hatter, Charles F. Wong
Life of this patent
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Abstract
Salts of tetrathiocarbonic acid are produced by a batch process in which a hydroxide, hydrogen sulfide, sulfur and carbon disulfide are reacted sequentially. The salts are produced as aqueous solutions having concentrations of upwards of 30 percent by weight.
Claims20
A batch process for producing an aqueous tetrathiocarbonate solution, the process (i) being performed in a reactor under an atmosphere essentially free of oxygen and (ii) comprising the sequential steps of:
- (a) reacting an hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, and magnesium hydroxide with a first sulfide in an aqueous solution to produce a second sulfide selected from the group consisting of sodium sulfide, potassium sulfide, lithium sulfide, calcium sulfide, and magnesium sulfide in the aqueous solution,
- (b) reacting the second sulfide with sulfur in the aqueous solution at a temperature of at least about 140.degree. F. to produce a reaction product in the aqueous solution, and
- (c) reacting the reaction product formed in step (b) with carbon disulfide at a temperature of 120.degree. to about 160.degree. F. to produce a tetrathiocarbonate in the aqueous solution, the tetrathiocarbonate being selected from the group consisting of sodium tetrathiocarbonate, potassium tetrathiocarbonate, lithium tetrathiocarbonate, calcium tetrathiocarbonate, and magnesium tetrathiocarbonate,
- wherein about 5 to about 15 percent excess hydroxide is added to the reactor, an excess of the first sulfide is added to the reactor, no unreacted sulfur is present in the aqueous solution at the commencement of step (c), and the sulfur is sprayed into the reactor in a molten state.
1 more element
A batch process for producing an aqueous tetrathiocarbonate solution, the process (i) being performed in a reactor under an inert atmosphere containing less than about 1.0 weight percent oxygen and (ii) comprising the sequential steps of:
- (a) reacting an hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, and magnesium hydroxide with a first sulfide in an aqueous solution to produce a second sulfide selected from the group consisting of sodium sulfide, potassium sulfide, lithium sulfide, calcium sulfide, and magnesium sulfide in the aqueous solution,
- (b) reacting the second sulfide with sulfur in the aqueous solution at a temperature of about 140.degree. to about 170.degree. F. to produce a reaction product in the aqueous solution, and
- (c) reacting the reaction product with carbon disulfide at a temperature of 120.degree. to about 160.degree. F. and a pressure of about 5 to about 20 psig to produce a tetrathiocarbonate in the aqueous solution, wherein the tetrathiocarbonate is selected from the group consisting of sodium tetrathiocarbonate, potassium tetrathiocarbonate, lithium tetrathiocarbonate, calcium tetrathiocarbonate and magnesium tetrathiocarbonate;
- about 5 to about 15 percent excess hydroxide is added to the reactor;
- an excess of the first sulfide is added to the reactor;
- the sulfur is sprayed into the reactor (i) as molten sulfur droplets having a particle size less than about 1/8 inch in diameter and (ii) without the molten sulfur droplets contacting the inside surface of the reactor;
- no unreacted sulfur is present in the aqueous solution at the commencement of step (c);
- and the carbon disulfide is added below the surface of the aqueous solution.
5 more elements
A batch process for producing an aqueous tetrathiocarbonate solution, the process (i) being performed in a reactor under an inert atmosphere containing less than about 1.0 weight percent oxygen and (ii) comprising the sequential steps of:
- (a) reacting an hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, and magnesium hydroxide with a first sulfide in an aqueous solution to produce a second sulfide selected from the group consisting of sodium sulfide, potassium sulfide, lithium sulfide, calcium sulfide, and magnesium sulfide in the aqueous solution,
- (b) reacting the second sulfide with sulfur in the aqueous solution at a temperature of about 140.degree. to about 170.degree. F. to produce a reaction product in the aqueous solution, and
- (c) reacting the reaction product with carbon disulfide at a temperature of about 135.degree. to about 140.degree. F. and a pressure of about 10 to about 15 psig to produce a tetrathiocarbonate in the aqueous solution, wherein the tetrathiocarbonate is selected from the group consisting of sodium tetrathiocarbonate, potassium tetrathiocarbonate, lithium tetrathiocarbonate, calcium tetrathiocarbonate and magnesium tetrathiocarbonate;
- about 5 to about 15 percent excess hydroxide is added to the reactor;
- an excess of the first sulfide is added to the reactor;
- the sulfur is sprayed into the reactor (i) as molten sulfur droplets having a particle size less than about 1/8 inch in diameter and (ii) without the molten sulfur droplets contacting the inside surface of the reactor;
- no unreacted sulfur is present in the aqueous solution at the commencement of step (c);
- and the carbon disulfide is added below the surface of the aqueous solution.
5 more elements
Dependencies are inferred from the claim text.