Dynamic material flow analysis of copper and its alloys in Japan

Transcription

1 LCM 2007, Zurich, August Dynamic material flow analysis of copper and its alloys in Japan Ichiro Daigo, Susumu Hashimoto, Yasunari Matsuno, Yoshihiro Adachi Graduate School of Engineering, University of Tokyo

2 Tools for a sound material cycle Material Flow Analysis Substance Flow Analysis (MFA/SFA) Conventional MFA/SFA studies paid little attention to the grade of the materials. Ore Upgraded (?) recycling Electrolytic Cathode copper Feedstock High-purity copper Copper alloys Closed-loop recycling Downgraded recycling Closed-loop recycling Recycling system in copper

3 Copper and copper alloys (Production) Highpurity copper Copper alloys Negligible small Cu contents Oxygen-free copper >99.90% Tough pitch copper >99.90% Phosphorous-deoxidized copper >99.90% Brass (copper-zinc alloys) % Free-cutting brass % High copper alloys >96.0% Tin bearing brass % Aluminum bronze % Source: Japan industrial standard

4 Copper and copper alloys (Scrap) Cu contents Copper scrap >97% Copper-alloy scrap >50% The instruction of census forms when scrap can not be recognized as high copper or copper alloys, it should be categorized as copper alloy scraps. Certain amounts of high-copper scraps have been collected as copper alloy scraps, such as high-purity copper being discarded without separation from copper alloys, or metal plating or other metal components being collected as copper alloy scraps.

5 Objectives A dynamic MFA was conducted separately for copper and copper alloys in Japan in order to estimate the stock and the potential for recycling of each of these materials.

6 Material stock and flow taken into account in this study Trades of materials Trades of finished products material production Domestic consumption Input (A) In-use stocks Output (H) (D) (B) (E) (F) (G) (C) Obsolete scrap Industrial scrap Dissipation Remaining Environment Landfill Export as mixed metals Loss into steel cycle Uncollected materials uncollected materials denotes disused materials that are not recovered domestically as copperbased scraps and that are lost from the domestic copper cycle.

7 Structure of Japanese copper industries Category of industry (they have each association) Electric wire and cable Copper fabricated products Category of metal grade High-purity copper Copper alloys Category in this study Electric wire and cable Copper fabricated products (Cu) Copper fabricated products (Cu alloys)

8 Population Balance Model; PBM Steel Production Use in products Discarded scrap The amount of steel products Investigation year Remaining rate Lifetime distribution of Steel-office buildings Lifetime distribution of Automotives Lifetime Age Year of manufacture 5 0

9 Dynamic MFA Generation*collection rate=obsolete scrap Remaining rate Data preparation -historic consumption -lifetime distribution of products Population balance model 自動車 AUT 建設 CONST 電気機械 EEE ケーブル W&C その他機械 MACH その他 Others Data preparation -Recovery rates of EOL products -Separation efficiency of metals Electric wire and cable Copper fabricated products Communication line and power cables 100% - Electric and electronic machinery 55% 55% Automobiles 61% 58% Other machinery 50% 50% Construction 80% 56% Others 23% 23% Collection rates for each end use Age/ year

10 Scrap generation (including uncollected materials) Discarded scraps / 1,000t 1,200 1, From Electric appliances From Automobiles From Construction From Other machinery From Electronic wire and cable From Others Year

11 Comparison of collected scraps Collected scraps [1,000t/ y] High- purity copper (EWC) High- purity copper (CFP) Copper alloys Statistics Year

12 Downgraded recycling Collected pure- Cu scraps [1,000t/ y] 1, Obs. from Electric appliances Obs. from Automobiles Obs. from Construction Obs. from Other machinery Obs. from Electronic wire and cable Obs. from Others Industrial scraps Statistics Year Collected high-purity copper scraps Collected Cu- alloy scraps [1,000t/ y] 1, Obs. from Electric appliances Obs. from Automobiles Obs. from Construction Obs. from Other machinery Obs. from Electronic wire and cable Obs. from Others Industrial scraps Statistics Year Collected copper alloy scraps

13 Estimated amounts of in-use stocks, and cumulative uncollected materials Stocks [1,000 t] 35,000 30,000 25,000 20,000 15,000 10,000 5,000 Cumulative uncollected materials Communication line and power cables Electric and electronic machinery Automobiles Other machinery Construction Others In- use stocks Year

14 Annual uncollected materials Annual uncollected materials [1,000t/ y] Communication line and power cables Electric and electronic machinery Automobiles Other machinery Construction Others Year

15 The possible final destinations for uncollected materials in 2000 Final destinations Total for Uncollected materials Landfill Loss into steel cycle Exported as mixed metals Other losses Net weight of copper [1000 t] * Proportion 100% 34% 12% 45% 9% * This was originally 160,000 tons in 1997, and was converted to the amount for 2000.

16 The cycle of high-purity copper in Japan for 2005 Import/Export Ore Copper products 152 Finished products 238 (Net exp.) 424 Old scrap Used products Exports as mixed metals 64 Production Mill, Smelter, Refinery 1190 Fabrication & manufacturing 743 Use 96 Stocks 639 Waste management Loss Landfill Other material cycles Environment Landfill 42 To other materials 10 To copper alloys

17 The cycle of copper alloys in Japan for 2005 Refinery Import/Export Cathode Copper alloy products 61 Finished products 93 (Net exp.) Scrap Used products Exports as mixed metals 32 Production Mill, Smelter Fabrication & manufacturing Use 36 Stocks Loss Waste management Landfill Other material cycles 223 Flash smelting Environment 104 To other materials Landfill 361 From high-purity copper

18 Conclusions Material stock and flow were dynamically analyzed on copper and copper alloys separately in Japan. The current in-use copper stock in Japan was estimated to be 18.7 million tons, and the amount of cumulative uncollected copper was estimated to be 9.9 million tons. The result indicates that almost all obsolete stocks are not stocks any more and have already gone into these three kinds of final sinks; landfill, mixing into steel cycle, and exports as the mix metals. The annual differences of estimation and statistics of collected copper alloy scraps; approximately 300 thousands tons, showed the amounts of high purity copper which are collected as copper alloy scraps. From these results, copper cycles in Japan distinguished by copper and copper alloys are drawn.

19 Thank you! Further information