Life cycle inventory analysis of CO₂ and SO₂ emission of imperial smelting process for Pb-Zn smelter

Abstract

Based on the principle of life cycle assessment, CO₂ and SO₂ emission of Imperial Smelting Process in a certain zinc-lead smelter was analyzed by life cycle inventory method. According to the system expansion and substitution method, the environmental impacts of co-products were allocated among the main products of zinc, lead and sulfuric acid. The related impacts were assessed by use of Global Warming Potential (GWP) and Acidification Potential (ACP). The results show that the GWP index from 1998 to 2000 is 11.53, 11.65, 10.93 tCO₂-eq/tZn respectively, the ACP index decreases from 14.88 kgSO₂-eq/tZn in 1998 to 10.99 kgSO₂-eq/tZn in 2000. Power and electricity generation, followed by smelting and zinc distillation, are mainly responsible for GWP. Sintering individually affects ACP. Reduction in greenhouse gas emissions of the ISP may come from energy conservation measures rather than from technological developments. And recycling more secondary Pb and Zn materials effectively treated by ISP, and reducing the amount of primary metal are the main ways to put SO₂ emission under control.

Keywords

impact assessment / life cycle inventory / imperial smelting process / zinc / lead