Catalyst recovery

Abstract From the Canadian patent

Process for the recovery of catalyst components from a catalyst residue, e.g. a residue obtained from the hydrocyanation of olefins, e.g. butadiene using a zero-, valent nickel complex promoted with a triarylborane as a catalyst by contacting the residue with an essentially aqueous solution of nitrogen-containing base e.g. ammonium hydroxide to form and precipitate the amine adduct of the triarylborane, while maintaining other catalyst components in solution and thereafter separating the percipitate from the resultant solution. Nickel can be separated from the resultant solution by reducing the concentration of amine in the solution to thereby precipitate a nickel cyanide complex, e.g. …