Succesful Zinc Residue Smelter Project For Xingan
In November 2013 Outotec signed a contract to supply Outotec Ausmelt technology, design services, and core equipment for a zinc residue smelter with a feed capacity of 160,000 tonnes a year. The client was Inner Mongolia XingAn Copper and Zinc Smelting Limited (XingAn). The new smelter is located inside an existing zinc roast-leach-electrowin facility at BaiYinHua Industrial Zone, West Ujimqin Banner, Xilingol League, Inner Mongolia, China. An additional agreement for the provision of site services was signed in June 2015.
Figure 1: XingAn Zinc Residue Smelter, Inner Mongolia, China
Benefits of Outotec Ausmelt zinc residue smelting technology
The XingAn zinc residue smelter is designed to treat zinc bearing feed materials, comprising a mix of hot leach residues, electric furnace residues, zinc dross and fume leach residues. These residues are usually classified as a hazardous waste due to the leaching of elements such as cadmium, arsenic and lead.
The versatility and flexibility of Outotec Ausmelt technology enables conditions within the furnace to be easily adjusted according to the specific application. Valuable metals including zinc, lead, silver, indium and cadmium are recovered to a fume product. The benign slag produced as a by-product of the process is safely discarded or used as a construction material.
Outotec Ausmelt technology for fuming of zinc bearing residues is easily integrated with Outotec’s hydrometallurgical and gas cleaning expertise to provide a tailored solution to meet specific client needs, ensuring cost efficiency and maintaining high environmental standards.
This is the first Outotec Ausmelt technology zinc residue smelter to be built since the return of the global marketing rights for the Outotec Ausmelt technology for the fuming of zinc bearing residues from Korea Zinc Company at the end of 2012.
Construction and Commisioning
XingAn implemented a skills development package that included Outotec TSL process and operational training and familiarization visits to other Ausmelt TSL sites to build on their existing zinc smelting skills. The plant design and construction was performed very quickly by XingAn. Cold commissioning of the Outotec equipment occurred over two weeks from mid-September 2015. Hot Commissioning of the smelter then occurred over three weeks from mid-October 2015.
At the completion of the very short Outotec Hot Commissioning phase, the furnace was operating at ~14 t/h of zinc residues, intentionally less than the design rate of ~25 t/h. XingAn was keen to ensure their operational crew were comfortable with the zinc smelting operations before increasing the feed rate to the design.
After hot commissioning XingAn gradually increased the smelting rate to the design rate of ~25 t/h. The recovery of zinc, silver and indium from the residues to the fume product are inline or exceeding expectations.
The timeline achieved by XingAn of two years from contract signing to achieving an operational Outotec Ausmelt TSL zinc smelting process at the design rate is a major achievement and a record for this size of commercial TSL facility.