About the 1996 TMS Annual Meeting: Wednesday Afternoon Sessions (February 7)

LEAD ZINC TIN PRODUCTION

Sponsored by: EPD Lead, Zinc, Tin Committee

Program Organizer: Engin Ozberk, Sherritt Inc., Fort Saskatchewan, Alberta, Canada

Wednesday, PM Room: A14-15

February 7, 1996 Location: Anaheim Convention Center

Session Chair: Engin Ozberk, Sherritt Inc., Fort Saskatchewan, Alberta, Canada

2:00 pm

PYROMETALLURGICAL TREATMENT OF ZINC RETORT RESIDUE BY SUBMERGED COMBUSTION IN-BATH SMELTING: Dhiren K. Panda, Kent D. Peaslee, David G.C. Robertson, Generic Mineral Technology Center for Pyrometallurgy, 215 Fulton Hall, University of Missouri-Rolla, Rolla, MO 65401

The zinc retort residues from old pyrometallurgical zinc production sites (in the Oklahoma-Kansas-Missouri tri-state area) pose an environmental problem, since they contain a significant amount of lead and zinc, among other contaminants. These residues were treated at the University of Missour-Rolla by the submerged combustion in-bath smelting (SCIBS) technique to fume off lead and zinc and obtain a non-hazardous slag. Details of the thermodynamic and kinetic modelling of the process are presented. Results of laboratory scale batch type experiments for studying the different operating parameters such as coke size, feed rate, fuming rate, (gas) blowing rate, etc. are highlighted.

2:25 pm

ECO-TECHNO-ECONOMIC SYNTHESIS OF PROCESS ROUTES FOR THE PRODUCTION OF ZINC USING SIMULATED ANNEALING: Markus A. Reuter, Sabina C. Sudholter, Mintek, Measurement & Control Division, Private Bag X3015, 2125 Randburg, South Africa

The demands placed on the environmental and social acceptability of metallurgical processing technology is rising steadily. Into the spotlight come the production techniques, products and disposal of residues. These aspects are affected by varying compositions of primary and secondary raw materials processed in these plants and the rapidly changing market situations in the metallurgical industry. The metallurgical engineers have to select "optimal" processes from a vast number of existing technologies for the primary production of zinc and for the processing of zince containing residues. To enable the engineer to compare these techniques and to choose the right combination of unit operations for this purpose on the most general basis, a process design methodology is presented, which has been adapted from methodologies developed in chemical engineering and minerals processing.

2:50 pm

THE USE OF OXYGEN IN LEAD SMELTING AND REFINING OPERATIONS: R. David Prengaman, Senior Vice President, Research & Development, RSR Corporation, 2777 Stemmons Freeway, Suite 1800, Dallas, TX 75207

In modern continuous lead smelting processes such as the QSL, Kivcet, Isasmelt and Ausmelt tonnage oxygen is used to oxidize sulfidic concentrates and residues to provide the major part of the energy for the process. The sulfur is evolved as SO2, and recovered as H2SO4 from a rich SO2 gas. In secondary lead smelting processes, using rotary or reverberatory furnances oxygen is used to accelerate smelting rates and reduce dust carryover by reducing gas flow. in these processes, however, care must be taken to restrict oxygen access to the charge to prevent evolution of SO2. Oxygen is also used to accelerate lead refining in both primary and secondary operations. This paper outlines the benefits of using oxygen in lead smelting and refining processes.

3:15 pm

LEAD RECYCLING PROCESS FOR SELECTIVE RECOVERY OF PRECIOUS METALS FROM ARGENTOPYRITE CONCENTRATE: J. R. Parga, G.G. Muzquiz, Technologico de Saltillo, A.P. 84C, 25000 Saltillo Coah Mexico

A shortage of landfill space and growing environmental concerns in Mexico are renewing interests in the recyclability of scrap from automobiles. This work describes a pyrometallurgical process for the recovery of metallic lead from waste lead paste. Argentopyrite concentrate is commingled with the lead paste residue and smelted in a fuming process therby transferring the precious metals into lead bullion. The process consists of smelting lead past and argentopyrite, sodium carbonate, and metallic iron at smelting temperatures of about 1100deg.C. The reaction products are slags and molten lead bullion enriched with precious metals. A major feature of this process is the removal of precious metals from the bullion by means of zinc, whereby a silver-zinc intermetallic compound is formed and floats out of the lead. The recoveries of precious metals are about 98%.