Patent ID: 7022641

Claim:
A method for preparing a metal cyanide catalyst, comprising mixing an acidic metal cyanide compound with an insoluble metal salt in a solvent medium for the acidic metal cyanide compound under conditions such that the insoluble metal salt and the acidic metal cyanide compound react to form a multimetal cyanide catalyst insoluble in the solvent medium, wherein: a) the acidic metal cyanide compound is represented by the general formula H w [M 1 (CN) r (X) t ] in which M 1 is a transition metal ion; each X represents a group other than cyanide that coordinates with the M 1 ion; r is from 4 to 6, t is from 0 to 2, and w represents the absolute value of the valence of the M 1 (CN) r (X) t group; and b) the insoluble metal salt is insoluble in the solvent medium and is represented by the general formula M x A y , wherein M is a metal ion that forms an insoluble precipitate with the metal cyanide grouping M 1 (CN) r (X) t , A represents an anion that forms a salt of M that is insoluble in the solvent medium, and x and y are integers that balance the charges in the insoluble metal salt.