OM Group, Inc. has announced two new management appointments within its base metals business.      Wayde Yeoman has been named to the newly created position of director, cobalt metal sourcing and marketing, reporting to Todd Romance, vice president and general manager, cobalt. In this capacity, Mr. Yeoman will have global commercial responsibilities for cobalt metal, raw material sourcing and balancing the company’s refined cobalt metal production levels with market demand. Mr. Yeoman came to ...