費用推定データベースによる採掘・選鉱プロセスのライフサイクルインベントリの推計

Abstract

Life Cycle Assessment (LCA) has been widely applied to evaluate environmental impacts regarding production and service activities. In a preparation stage for LCA, a catalog called Life Cycle Inventory (LCI) should be developed, summing up resources inputs, outputs and environmental burdens. However, in most of LCI studies, mining activities are excluded from their system boundary because of the difficulty in data acquisition from foreign mine sites especially for Japan. Systematic LCI on mining activities is needed for more accurate LCA.In this paper, a database to estimate LCI on the mining and mineral processing activities is constructed using the cost functions of CES(Cost Estimating System, USBM). This database called MLED (Mining LCI Estimating Database) provides standard CO2 emission level for each production style on mining and beneficiating process. MLED with data input-output interfaces automatically calculates CO2 emissions as well as consumptions of energy and materials.Two case studies are carried out using MLED. One is for an underground copper mine in South America. CO2 emissions for various production rates and mining methods have been estimated to compare with the present mining process on this site. In the second case study, CO2 emissions in a large scale surface mine in Chile have been estimated and compared with actual data of this mine to verify the validity of MLED.Considering the recent situation in environmental regulations, inventory estimating model such as MLED will become one of the useful tools to estimate the environmental burdens and improve the mining design.