Bernhart K. (Braney) Haffner, 62 an expert on minerals, mining and metal processing for the Department of Commerce, died of an Aneurysm Wednesday at Northern Virginia Doctors Hospital.

Mr. Haffner was born in Ray, Ariz. and grew up in Neveda. He graduated from the California Institute of Technology and earned a master's degree in economic geology and mining engineering from Queen's University in Kingston, Ontario, in 1941.

He then joined the National Lead Co. in Tahawus, N.Y., as a chief engineer and geologist. After serving as an official with the state Department in the Netherlands and in Indonesia from 1948 to 1950, he returned to National Lead as executive manager of one of the company's subsidaries, the Nicaro Nickel Mining Co. of Cuba.

Before joining Commerce in 1960, he was vice president of the American Coldset Corp. in Peterboro, N.Y., for three years.

Mr. Haffner began his career at Commerce as a consultant to the deputy administrator for business and defense services and was an industrial specialist in the office of business policy analysis at his death.

In 1976, he received the Commerce Department's Silver Medal in recognition of his contributions in the field of environmental policy and analysis.

Mr. Haffer lived in Alexandria. He was a member of the American Institute of Mining Engineers, the American Society of Tool Engineers and the Printed Circuit and Chemical Milling Society.

Survivors include his wife, Ann Duncan Haffner of the home; a son, John of Salisbury, Md., two daughters, Julie H. Renard of Huntington, N.Y., and Jeanette H. Turnbull of Philadelphia; a brother, Robert L., of Spokane, Wash., and two grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Sheltered Enterprisers in Alexandria. CAPTION: Picture, Bernhard K. Haffner