July 8, 2009 - Xstrata's ISASMELT top submerged lance (TSL) smelting technology has been chosen for its fifth smelter project in China.  It has recently signed a contract with Yunnan Chihong Zn and Ge Co. Ltd. (a subsidiary of Yunnan Metallurgical Group, YMG).  Philip Arthur, general manager-pyrometallurgy, said Xstrata Technology* (XT) would provide a lead smelting technology licence, engineering services, equipment and commissioning services for the Huize lead smelter project in Yunnan Province.  The new “green-field” smelter will combine an ISASMELT^TM furnace with a blast furnace to smelt lead concentrates and zinc leach plant residues. XT and YMG jointly developed the innovative TSL-blast furnace process, patented as the ISA-YMG process.  The first installation has been operating at Yunnan Chihong’s Qujing smelter in Yunnan for four years, and will be followed by the Kazzinc project in Kazakhstan (expected to be commissioned in 2010) and then the Huize plant.  Arthur said “Xstrata’s extensive experience in lead smelting includes operating a two-stage TSL at our own Mount Isa lead smelter for several years. The ISA-YMG process has distinct advantages over the two-stage TSL process. We expect it will become the technology of choice for new lead smelters to achieve low emissions and high efficiency.”
The intense mixing in TSL is ideal for oxidation and produces a high strength gas for sulphur capture, while blast furnaces are more efficient for reduction due to the counter-current flow of reductant gases and feed.
“The ISA-YMG process combines the best of both technologies, decoupling two continuous processes with an intermediate stockpile of solids,” said Arthur.   “The Huize project marks the return of Xstrata Technology’s ISASMELT^TM technology into the highly competitive Chinese smelting market. Many of the world’s future smelting projects are expected to be in China, and Xstrata Technology has refined its business model to offer a streamlined technology package to suit this important market.”