US 4,301,014 A · Phosphorus pentasulfide waste water treatment

Abstract

The process disclosed in this invention takes the waste solids, gases, and water from a phosphorus pentasulfide manufacturing facility and hydrolyzes the phosphorus pentasulfide by heating. The phosphorus portion is converted to a soluble phosphate and the sulfur portion to a mixture of sulfide, sulfite and sulfate. The soluble fraction is then treated with a calcium hydroxide solution precipitating the phosphate and sulfates which are removed. The gaseous portion of the hydrolysis is fed to a catalytic oxidizer which converts the sulfides to sulfur, which is removed and the gas, free of sulfur containing species, is exhausted to the atmosphere. The filtrate from the precipitation reaction can be recycled to the plant, or may be chlorinated and discharged.

Claims19

Dependent claims

A process for the treatment of waste water resulting from the manufacture, use or storage of phosphorus pentasulfide comprising:

a. collecting the waste water,
b. hydrolyzing the P.sub.4 S.sub.10 to phosphates, sulfides, sulfites and sulfates,
c. filtering the hydrolysis mixture to remove any unreacted P.sub.4 S.sub.10, returning the insolubles for further hydrolysis,
d. treating the soluble portion of the hydrolysis step with a solution of cation that will react with the soluble phosphate anion to precipitate,
e. removing the precipitate from the mixture,
f. oxidizing the filtrate, adjusting the pH, filtering to remove any solids to allow discharge to the environment.
g. passing the gaseous output of the hydrolysis step b. into a catalytic scrubber to remove the sulfur, and
h. venting the gaseous output from the scrubber to the atmosphere.

5 more elements

Dependencies are inferred from the claim text.

Phosphorus pentasulfide waste water treatment

Life of this patent

Phosphorus pentasulfide waste water treatment

Life of this patent

Abstract

Claims19