This series contains plant and equipment records as well as ore shipment records.

The diversification program manual outlines proposals for effective functional operation of product and market development; research and development activities; merger, acquisition, joint-venture and new plant construction proposals; and liaison with industry activities.

Equipment records include blueprints and instructions for automatic station and switching equipment.

Among the ore shipment ledgers are settlement sheets, assays and bills of lading for copper residue shipments, 1966-1972; a daily summary of zinc plant operations, January-June 1945; a spiral bound booklet describing operations of each of the departments of the mine visited by the board of directors of Gulf Resources in 1968; and a computer generated stock control master inventory record listing all supplies on hand as of December 8, 1981. Also included are sheets documenting daily mill runs at both the south and west mills, 1930-1938, and 2 bound volumes of ore statements and smelter settlements, 1925-1930 which contain assays and shipping data. The mill assay records span the years 1906 to May 1955, with the exception of the volume for July 1926 to November 1940 which was lacking. The dump slag book, 1955-1970, keeps track of monthly amounts of slag received from the roasters and furnaces.