Enviroplas Technology for the Recovery of Lead and Zinc from Lead Blast Furnace Slags


The extraction of zinc and lead from liquid slags from lead blast and imperial smelting furnaces direct into a lead splash condenser may offer an economically attractive alternative to fuming zinc and lead as oxides, since these oxides require further treatment to produce metal. Mintek conducted four campaigns during 1994/95 on the 5,6 MVA multi-purpose demostration-scale pilot plant to test the production of zinc metal direct from lead blast furnace slags (LBFS) and other sources such as residues and EAF dusts. Typically the plant was operated at 1 t/h of slag, which was either fed direct as solid feed or premelted in a dc plasma-arc furnace to simulate hot slag from a lead blast furnace and continuously trandsferred at about 1300° C via a lau nder to a second dc plasma-arc fuming furnace through an underflow weir. The latter furnace was batched tapped approximately every two hours to remove slag, and limited quantity of metal (mostly iron) was tapped up to twice a day. The fuming furnace was also tapped continuously for several days at a time. The results achieved prove that PW ( Prime Western) grade zinc can be readily made using an ISP lead-splash condenser linked to a dc plasma-arc fuming furnace. The final quenched slag consistently meets US EPA TCLP leach criteria, which is a critical aspect of the process. The pilot plant equipment proved to be reasonably relaible once the initial commisioning problems were overcome, and relatively few conceptual changes are envisaged at the full industrial scale.

Meeting Name

International Lead and Zinc Study Group 6th International Conference (1995: Jun. 18-23, Madrid, Spain)


Materials Science and Engineering

Document Type

Article - Conference proceedings

Document Version


File Type





© 1995 International Lead and ZInc. Study Group, All rights reserved.

Publication Date

01 Jan 1995

This document is currently not available here.