Nickel powder precipitation by high-pressure hydrogen reduction

Includes abstract.Includes bibliographical references (leaves 87-91).The effect of impurities on the precipitation behaviour of nickel powder produced by high-pressure hydrogen reduction was investigated in order to determine the factors responsible for the formation of powder with undesirable morphology. In nickel precipitation by hydrogen reduction, two product morphologies have been observed: the spherical, open powder (desirable) and the spherical, closing/closed powder (undesirable). Two major impurities were studied namely; a morphology modifier (a polyacrylic acid derivative) used as an additive and iron which is an inherent impurity