Zinc Column Design at Ozark-Mahoning

Flotation columns continue to offer improved metallurgical and economic advantages over other flotation methods. Pilot testing at Ozark-Mahoning Co. in Rosiclare, IL led to installation of one 2.3-m-diam (7.5-ft-diam) column for zinc roughing and one 1.1-m-diam (3.5-ft-diam) column for zinc cleaning. This circuit replaced one stage of mechanical roughing-scavenging followed by two stages of cleaner flotation. General Column flotation continues to make inroads into applications traditionally dominated by mechanical flotation cells. For example, columns are becoming more visible as rougher flotation devices. At Royal Mountain King Mine in California, two 2.9-m-diam (9.5-ftdiam) columns are used for rougher flotation of carbon from a gold ore (Orlich et al., 1992). In addition, work performed at BRGM in France demonstrated the superiority of column flotation over mechanical flotation with respect to design of new plants (Morizot et al., 1991). The primary reasons for this acceptance of columns are a general improvement in design, scale-up and operation, as well as improvements in sparger design and performance. With these advances, the full benefits of column flotation can be realized. The benefits of properly designed, aerated and operated flotation columns include lower capital costs, reduced operating costs, fewer processing stages and improved metallurgical performance.