Environmental assessment of metals through dynamic modelling of the metal life cycle system Table of figures ......................................................................................................... 4 Table of tables ........................................................................................................... 6 Table of tables ........................................................................................................... 6 Summary ................................................................................................................... 7 1 Introduction ....................................................................................................... 9 1.1 Metal production and recovery system ....................................................... 9 1.2 Assessment of the metal production system.............................................. 10 1.3 Objectives ................................................................................................ 10 1.4 The structure of the report ........................................................................ 11 2 Environmental assessment ............................................................................... 12 2.1 Material Flow Analysis ............................................................................ 12 2.2 Life Cycle Assessment ............................................................................. 12 2.2.1 Goal and scope definition ................................................................. 13 2.2.2 Inventory analysis ............................................................................ 13 2.2.3 Impact assessment ............................................................................ 13 2.2.4 Interpretation .................................................................................... 14 2.3 Substance Flow Analysis ......................................................................... 14 2.3.1 System definition ............................................................................. 14 2.3.2 Quantification of the overview of flows and stocks........................... 14 2.3.3 Interpretation of the results ............................................................... 15 2.4 Differences and similarities in LCA and SFA ........................................... 15 2.5 Impact assessment in the metal life cycle ................................................. 16 2.5.1 Goal and scope ................................................................................. 16 2.5.2 Inventory .......................................................................................... 17 2.5.3 Impact assessment ............................................................................ 18 3 Modelling of the metal life cycle ..................................................................... 20 3.1 Software for constructing the model ......................................................... 20 3.2 Mining ..................................................................................................... 21 3.3 Metal Production ..................................................................................... 22 3.3.1 Modelling unit operations ................................................................. 22 3.3.2 Flow sheets ...................................................................................... 27 3.3.3 Intermediates .................................................................................... 28 3.4 Products Manufacturing ........................................................................... 29 3.5 Consumption ............................................................................................ 30 3.6 Solid Waste Management ......................................................................... 30 3.7 Scenarios ................................................................................................. 31 3.8 The Inventory Analysis and the Life Cycle Assessment ........................... 31 3.8.1 Eco-indicator’99 method .................................................................. 31 4 Metal production flow sheets ........................................................................... 34 4.1 Bismuth ................................................................................................... 34 4.1.1 Mining & Production....................................................................... 34 4.1.2 Manufacture and consumption .......................................................... 36 4.1.3 Solid waste management .................................................................. 36 4.2 Copper ..................................................................................................... 36 4.2.1 Production ........................................................................................ 36 4.2.2 Manufacture and consumption .......................................................... 39 4.2.3 Solid waste management .................................................................. 39 4.3 Gold ......................................................................................................... 40 4.3.1 Production ........................................................................................ 40 4.3.2 Manufacture and consumption .......................................................... 41 4.3.3 Waste management .......................................................................... 41 4.4 Lead ......................................................................................................... 42 4.4.1 Production ........................................................................................ 42 4.4.2 Production and manufacture ............................................................. 44 4.4.3 Waste management .......................................................................... 45 4.5 Nickel ...................................................................................................... 46 4.5.1 Production ........................................................................................ 46 4.5.2 Manufacture and consumption .......................................................... 49 4.5.3 Waste management .......................................................................... 49 4.6 Platinum Group Metals ............................................................................ 50 4.6.1 Production ........................................................................................ 50 4.6.2 Waste management .......................................................................... 51 4.7 Silver ....................................................................................................... 51 4.7.1 Production ........................................................................................ 51 4.7.2 Manufacture and consumption .......................................................... 53 4.7.3 Waste management .......................................................................... 53 4.8 Tin ........................................................................................................... 53 4.8.1 Production ........................................................................................ 53 4.8.2 Manufacture and consumption .......................................................... 56 4.8.3 Waste management .......................................................................... 56 4.9 Zinc ......................................................................................................... 56 4.9.1 Production ........................................................................................ 56 4.9.2 Manufacture and consumption .......................................................... 58 4.9.3 Waste management .......................................................................... 59 5 Results ............................................................................................................. 61 5.1 Calculation of the environmental impact .................................................. 61 5.1.1 LCA calculation with allocation based on non-causal relationships .. 62 5.1.2 LCA calculation with allocation based on casual relationships ......... 65 5.1.3 LCA calculation with avoided allocation through system expansion . 65 5.2 Results for individual metals .................................................................... 67 5.3 Marginal changes: DVDs ......................................................................... 69 5.4 Product Substitution: Lead free soldering ................................................. 71 5.5 Drastic change: 16.5% lower copper demand ........................................... 75 6 Sensitivity Analysis ......................................................................................... 76 6.1 Analysis ................................................................................................... 76 6.1.1 Emission of gasses ........................................................................... 76 6.1.2 Transportation .................................................................................. 76 6.1.3 Recycling ......................................................................................... 77 6.1.4 New scrap ........................................................................................ 78 6.2 Changes to the flow sheet ......................................................................... 79 7 Conclusions