1997 TMS Annual Meeting: Monday Abstracts

GENERAL RECYCLING: Session II: Practice

Session Chairpersons: James C. Daley, Daley & Associates, 1020 W. Cactus Wren Drive, Phoenix, AZ 85021; John M. Rapkoch, Davy International, 2440 Camino Ramon, San Ramon, CA 94583

RECYCLING OF MAGNESIUM ALLOY SCRAP, A NECESSITY: Christine Brassard, Lisabeth Riopelle, Oddmund Wallevik, Hydro Magnesium Market Development Center, 21644 Melrose Avenue, Southfield, MT 48075-9705

The use of magnesium alloys is growing rapidly, particularly in die cast parts for the automotive industry. Supporting this growth in the future means that Mg has to be an economically and ecologically attractive material, and recycling of alloy scrap becomes a necessity. What kinds of magnesium scrap will be on the market? What are the opportunities and challenges for this emerging recycling industry? Different recycling processes have been developed, and operation facilities are today recycling large volumes of class 1 diecast returns based on a flux refining technology. Characterization of the recovered metal demonstrates that the performance of appropriately recycled magnesium alloy is comparable to an alloy made from primary electrolytic metal. The sludge generated from this process can also be recycled through the existing primary Mg operations in order to close the environmental loop.

1:55 pm

INMETCO CADMIUM RECOVERY FACILITY: George Cingle III, INMETCO, 245 Portersville Road, Ellwood City, PA 16117; Gerald LaRosa, Davy International, One Oliver Plaza, Pittsburgh, PA 15222

The INMETCO Cadmium Recovery Facility currently processes commercial and industrial nickel/cadmium batteries at their Ellwood City, PA plant. The facility receives recycled nickel/cadmium batteries to recover cadmium shot product and nickel/iron scrap. The technology employed for the dismantling of industrial cells and the distillation of cadmium is under license from SAFT-NIFE in Sweden. In addition, INMETCO has installed a thermal pretreatment pilot unit for processing commercial and consumer cells which has recently demonstrated encouraging results. The INMETCO facility began detailed design in February 1995. The first cadmium distillation furnace was brought on-line December 1995, and the complete facility was operational April 1996. The facility can process 2450 short tons per year of industrial cells and 630 short tons per year of consumer cells. The facility design incorporated provisions for future expansion to allow INMETCO the ability to keep up with the forecasted growth of recycling nickel/cadmium batteries through the year 2000.

2:20 pm

COPPER RECYCLING FROM INDUSTRIAL WASTE BY MATTE SMELTING: Kazuhiro Asai, Yasuhito Kawasaki and Junzo Hino, Nippon Mining & Metals Co. Ltd., Toranomon 2-10-1, Minato-ku, Tokyo 105, Japan

Hitachi Refinery of Nippon Mining & Metals Co., Ltd. installed a reverberatory type recycling furnace in 1978 in order to treat the industrial wastes which contain metal elements such as copper, gold and silver. Waste materials and pyrite such as galvanizing sludge, hydroxide slime and dust, are smelted together, and sulfidized copper, iron and precious metals are transformed into matte and other metallic elements are oxidized into slag. This copper matte is transported to Saganoseki smelter, and copper and precious metals are recovered. Recently it became difficult to get pyrite economically because of the decrease of pyrite production. Therefore, new treating process of the liquid waste has been investigated at Hitachi. In this process, the sulfide or sulfate from the liquid waste are smelted as the sulfur source instead of pyrite.

2:45 pm BREAK

3:00 pm

THE SUBMERGED ARC FURNACE AND ITS APPLICATION IN THE NON-FERROUS RECYCLING INDUSTRY: Gero Rath, Mannesmann Demag, Huttentechnik MDH

Residues from the non-ferrous industry contain highly valuable metallic substances which make their recovery by thermal treatment desirable from the economic and environmental point of view. The electric slag resistance furnace, a variant of the submerged arc furnace is one which is used more frequently for these recycling purposes. In the last decade Mannesmann Demag has built and commissioned most of these furnaces. The paper will give an overview of the operational applications and characteristics based on the experience gained so far in lead and copper recycling.

3:25 pm

AUTOMATIC SORTING OF ALUMINUM PACKAGINGS FROM DOMESTIC REFUSE: G.J. Nijhof ea., Hoogovens R&D, P.O. Box 10.000, 19709 CA IJmuiden, The Netherlands

This work is part of a major European research project on the re-use of packaging materials in their post consumer state. The first stage of the recovering of aluminum from a waste stream is to free the non-ferrous metals with an Eddy Current machine. Previous research has given excellent results on the separation of aluminum from pre-separated packaging material. At this moment there were two reasons for a new test series: In the Netherlands all cities are obliged to collect the organic waste separately from the other waste, thus leading to a rest fraction with a high potential on aluminum. The newest generation Eddy Currents work with a higher separation efficiency. This report will discuss the results of these test series. The recovered aluminum is used for remelting trials in another sub-project of this research programme.

3:50 pm

PILOT SCALE INVESTIGATION OF FLEXIBLE ALUMINUM PACKAGING BY THERMAL PRETREATMENT: H. Rossel, R. Pietruck, VAW aluminum AG, Research & Development, Georg-von-Bosselager-Strabe 25, 53117 Bonn, Germany; Y. Bertaud, Y. Caratini, Pechiney CRV, Vorreppe, France

Laminates with aluminum are typically combined with other materials like plastics, paper, etc. The aluminum content is considerably below 50%. Therefore the separation of the laminate partner by a thermal procedure before the melting process is a successful solution. The paper reports the practical experiences with a pilot equipment in the 100kg-scale. Additionally the numerical approach to simulate the thermal process is presented. This work is part of a major European research project (PACK-EE) on the re-use of packaging materials in their post consumer state. Preliminary information on this project can be found in Light Metals, 1996.

4:15 pm

REMELTING AND PURIFICATION OF ALUMINUM PACKAGING WASTE: G.H. Nijhof ea., Hoogovens R&D, P.O. Box 10.000, 1970 CA IJmuiden, The Netherlands

This work is part of a major European research project on the re-use of packaging materials in their post consumer state. Recovering aluminum from household refuse leads to a mix-up with other metals, e.g. copper and steel. The aluminum industry aims to make packaging materials from waste packagings. Therefore, a purification step is required during the remelting operation. This research is focused on the removal of excess iron from the melt. The technique used is the formation of intermetallic compounds of FeMn by adding Mn, followed by separating these intermetallics from the molten metal. Theoretical studies of the ternairy and quarternairy phase diagrams, using computer modeling, have predicted the possible limits of purification. After laboratory trials some large scale remelting experiments have been performed to study the applicability of this technique.