Top Submerged Lance (TSL) Direct Zinc Smelting

摘要

From the first trials and pilot plant studies in the 1980s, Ausmelt has had a long history of processing of zinc, with presently close to 800,000 tonnes a year of zinc bearing feeds passing through Ausmelt furnaces in the form of residues and slags. Since inception, Ausmelt Top Submerged Lancing (TSL) Technology has gained widespread commercial acceptance in non-ferrous applications, including the processing of copper, lead, tin and zinc bearing materials. TSL is highly flexible and efficient, and is one of the few technologies which can process primary and secondary feeds, and use varying fuels, to deliver high recoveries and excellent environmental performance. Ausmelt continues to be a pioneer in the treatment of zinc bearing feeds by developing processes to treat secondary materials such as EAF dusts to recover both the iron and zinc credits along with direct zinc smelting of zinc sulphide concentrates. Commercially, Ausmelt's continued belief in the ability of the technology to process zinc has led it to invest in the Waste Recovery Facility at Whyalla, that has been designed to toll smelt 55,000 tonnes a year of primary leach reside for Nyrstar to recover zinc credits. The newest development in zinc, the Ausmelt Direct Zinc Smelting (DZS) process in a TSL furnace is a novel process proposed by Ausmelt to meet the growing needs of the primary Zinc smelting industry. It overcomes inherent limitations associated with the traditional Roast-Leach- Electrowinning (RLE) process in order to achieve higher recoveries of both Zn and the valuable elements (e.g. Cu, Ag, Au, Ge & In) associated with it while eliminating the creation of large volumes of residues. The DZS process has distinct economical and environmental advantages as compared to the RLE process, when confronted with concentrates containing higher quantities of non-volatile components (e.g. Fe, Mn, SiO2, MgO, Ni and Co) those elements are relegated to a benign slag for optimum disposal instead of producing a residue (e.g. Jarosite, Goethite, Hematite) that must be further treated, but which are normally stored or dumped. The DZS process has the potential to revolutionise the pyrometallurgical primary zinc production industry.