Chanderiya Lead-Zinc Smelter
Overview
Chanderiya Lead-Zinc Smelter (CLZS) stands as one of the world’s largest zinc-lead smelting complexes, with a current annual metal production capacity of 704,000 MT, encompassing 609,000 MT of zinc and 95,000 MT of lead. In the fiscal year ending March 2023, CLZS achieved production figures of 503,821 MT of zinc and 94,989 MT of lead. Its primary products include special high-grade (SHG) zinc, continuous galvanizing grade (CGG) zinc, prime western (PW) zinc, and pure lead. Additionally, CLZS generates several valuable by-products, including silver.
Driven by a synergy of proven technology and innovative practices, Chanderiya consistently advances its environmental and operational performance, maintaining its positioning as one of the world’s largest and most efficient zinc and lead smelting complexes.
Key Facts
- Location : 110 km North of Udaipur, Rajasthan, India
- Technology : Imperial Smelting Technology Roast Leach Electro-winning Technology AusmeltTM Technology
- Products : SHG regular, SHG Jumbo, Zamak-3, pure lead, PW Zinc & Silver
- Annual Product Capacity : Zinc 558,000 tonnes per annum Lead 85,000 tonnes per annum Silver 168 tonnes per annum
- Certifications : ISO 9001:2015, ISO 14001:2015, OHSAS 45001:2018, SA8000, EnMS 50001 & 5S, CII GreenCo Gold Certified Unit
Background Information
Situated 110 km North of Udaipur in Rajasthan, India, CLZS was commissioned in 1991. It has a Lead-Zinc Pyrometallurgical Smelter, an Ausmelt Lead Smelter, and two HydroMetallurgical Zinc Smelters.
Process Description
Roast Leach Electro-Winning (RLE):
The hydrometallurgical smelting process at our facility follows the roast, leach, and electro-winning (RLE) approach. Initially, zinc concentrate undergoes oxidation in the roaster, while the resulting gases are purified and directed to the sulphuric acid plant. The primary product, known as calcine, proceeds to the leaching plant, where it is transformed into a zinc sulphate solution.
This solution then undergoes a cold/hot purification process, yielding purified zinc sulphate. Through electrolysis, the purified zinc solution is transformed into zinc cathodes. Eventually, these zinc cathodes are molten and cast into the form of zinc ingots, completing the comprehensive process.
Imperial Smelting Process (ISP) Description:
The Pyrometallurgical smelter employs the Imperial Smelting Process (ISP), commencing with sintering. Lead and zinc concentrates, combined with bulk concentrates, are blended with secondaries and fluxes. Passing through the sinter machine eliminates sulphur, and resulting gas is directed to the sulphuric acid plant. After size reduction, the desulphurized output enters the Imperial Smelting Furnace (ISF), smelted with preheated met-coke and air.
The ISF simultaneously produces molten zinc and lead. Chemical reactions with preheated coke create carbon monoxide and heat, smelting the metallic oxide into elemental metal. Molten lead is tapped, while zinc vapour is condensed in the condenser and absorbed by lead. Zinc undergoes further refining through a Double distillation column. The process produces zinc as the primary product and Cadmium as a by-product.
Waste gases from the ISF are cooled and cleaned, utilising low calorific value for furnace air preheating and coke preheating. Excess gases generate steam through a Boiler for plant operations.
