Cytec Technology Corporation

Inco Limited

Compagnie Des Mines De Xere (cmx)

Yoshiaki Okita

Eberhard Krause

Reichel A Tenbergen

Justin Raskauskas

Dennis Frederick Colton

Jean Paul Duterque

Jean-Jacques Robert Perraud

Brian Charles Blakely

This is a method of regenerating dithiophosphorus acids from disulfides containing sulfur--sulfur bonds, formed by oxidation of dithiophosphorus acids, such as sulfur--sulfur bonding of dithiophosphoric, dithiophosphonic and dithiophosphinic acids, in a solvent extraction organic phase in which the dithiophosphorus acid is dissolved in a diluent. This process reacts metal directly with the organic solution containing the disulfide to produce a metal loaded complex form of the regenerated dithiophosphorus extractant in the organic solution. This metal complex forms by direct reaction of the metal with the disulfides without requiring the presence or the formation of nascent or gaseous hydrogen. The organic solution containing the regenerated dithiophosphorus extractant can be either directly recycled into a solvent extraction circuit or recycled after the loaded metal is stripped.

Hydrogen-free regeneration of dithiophosphorus metal extractants

The process provides a method of removing arsenic from solutions containing sulfur dioxide in an environmentally acceptable manner. This process first oxidizes arsenic, iron and sulfur dioxide contained in an aqueous solution to prepare the solution for precipitation and to improve process control. Recycled neutralized precipitate seeds the oxidized aqueous solution. A calcium-containing base precipitates products of neutralization on the seeds. The final neutralized precipitate contains a stable ferric arsenate compounds.

Removal of arsenic from iron arsenic and sulfur dioxide containing

Growing community of inventors

St. Catherines, Canada

Yoshiaki Okita