Powder preparation is started by combining the oxides of manganese or nickel and zinc with iron oxide in a batch-and-mix process according to the specification of the engineer’s requirements for the materials to achieve the required standards. The powder is then sent to the kilns for a calcine process in order to combine the mixed materials and start the crystallization process. The powder is examined for chemical analysis and milled down to the standard specification. It is then mixed into a slurry with the needed binders, spray-dried back into a powder, mixed with zinc stearate as a lubricant, and vibration-sifted for acceptable particle size.