Monitoring the Resources and Environmental Impacts from the Precise Disassembly of E-Waste in China

Investigating precise disassembly throughmaterial flowanalysis provides the possibilities to reduce mixed metals which needto be smelted. This study paves the way for lower carbon emissione-waste recycling. Due to the dispersed distributionof e-waste and crudedisassemblyin traditional recycling, valuable metals are not traceable duringtheir life cycle. Meanwhile, incomplete separation between metalsand nonmetals reduces the economic value of disassembled parts, whichleads to higher environmental costs for metal refining. Therefore,this study proposes a precise disassembly of e-waste to finely classifyand recover metals in an environmentally friendly way. First, themacroscopic material flow of e-waste in China (source, flow, scrap,and recycling gap) was measured based on data collected by the governmentand 109 formal recycling enterprises. The sustainable recycling balancetime points for e-waste recycling and scrap volumes were forecastby introducing an additional recycling efficiency. By 2030, the totalscrap volume of e-waste is predicted to reach 133.06 million units.For precise disassembly, the main metals and their percentages fromthese typical e-wastes were measured based on material flow analysiscombined with experimental methods. After precise disassembly, theproportion of reusable metals increases significantly. The CO2 emission of precise disassembly with the smelting processwas the lowest compared with crude disassembly with smelting and oremetallurgy. The greenhouse gas for secondary metals Fe, Cu, and Alwas 830.32, 1151.62, and 716.6 kg CO2/t metal, respectively.The precise disassembly of e-waste is meaningful for building a futureresource sustainable society and for carbon emission reduction.