A Mixed Integer Programming Model for the Multiperiod Scheduling Problem of Blending Zinc-Bearing Materials to Minimize
- PDF / 401,224 Bytes
- 9 Pages / 593.972 x 792 pts Page_size
- 24 Downloads / 206 Views
THE typical hydrometallurgical processes extracting zinc from zinc-bearing materials consist of blending, roasting, leaching, purification, electrowinning, and casting. The blending process involves mixing of several kinds of zinc-bearing materials of different compositions. The roasting process involves the roasting of the zinc-bearing material at 950 C to produce zinc oxide (ZnO) and zinc ferrite (ZnFe2O4) when iron is present in it.[1] The leaching process consists of dissolving the solid in dilute sulfuric acid to produce zinc sulfate in solution.[2,3] The purification process removes the impurities by feeding additives to obtain satisfactory electrolyte. The electrowinning process recovers high-purity metal zinc of the purified zinc sulfate solution.[4] The casting process consists of melting the zinc recovered by electrowinning and pouring it into a mold to obtain a zinc ingot.
SEONG-IN KIM is Outside Director, Young Poong (Seok Po Zinc Refinery) Co., and Professor, Division of Information Management Engineering, Korea University. Contact e-mail: [email protected] YOUNGHO LEE, Professor, and IBRAHIM A. HAMEED, Postdoctoral Student, are with the Division of Information Management Engineering, Korea University, Seongbuk-ku, Seoul 136-701, Korea. JUNGHEE HAN, Professor, is with the Department of Management, College of Business Administration, Kangwon National University, Chuncheon-si, Kangwon-do 200-701, Korea. BO-KYUNG SHIM, Researcher, is with the Project Management Team, Samsung Engineering Co., Kangnam-ku, Seoul 135-826, Korea. Manuscript submitted May 21, 2008. Article published online November 4, 2008. 896—VOLUME 39B, DECEMBER 2008
A number of studies exist on the efficient operation and management of the overall zinc processes,[5] leaching process,[6,7] purification process,[8] and electrowinning process.[9] This study focuses on the efficient operation and management of the blending process, the first step in the hydrometallurgical zinc process, in which some zinc-bearing materials are selected from various kinds of materials containing different components and their mixing ratios are determined. Blending is an important process affecting the operation methods and efficiency of the succeeding processes and the quality of the final zinc product. This study employed the Seok Po Zinc Refinery of Young Poong Co. as an application plant. The Seok Po Zinc Refinery imports 15 kinds of zinc-bearing materials, selects 4 kinds from them, and determines the mixing ratios. In the blending process, the contents of components such as Fe, Cu, Pb, Co, and SiO2, as well as their particle sizes, are considered. The contents of these components in the materials differ depending on the mines in which they were produced. For example, the content of Fe is 5.92 pct in the material from Antamina (AM) and 13.12 pct in the material from Paragsha (PG), whereas the upper specification of Fe is 13.00 pct for the blended material. The content of Cu is 2.66 pct from AM and 0.27 pct from Broken Hill (BH), whereas the upper specification of Cu is 0.61 p
Data Loading...
