金属工业的回收利用外文原文以及翻译.docx

Recycling in the Metals Industry arry V. Makar n 1990, scrap was a major feedstock component of U.S. metals production. Steel scrap represented 56% of raw steel production, old lead scrap was 66% of total lead production, and purchased aluminum scrap represented 37% of total production. Copper scrap makes up 44% of total U.S. copper consumption annually. Although some recycling operations, such as past (but now obsolete) lead-acid battery breaking and the use of high salt fluxes on aluminum drosses have created environmental problems, the recovery of obsolete autos, cast or extruded products, appliances, lead-acid batteries, beverage containers, and drosses represents major environmental benefits in terms of reduced litter, landfill wastes, and energy savings. Evolving technologies, marketing concepts, and regulations promise even higher levels of recycling in the future. The cumulative amounts of aluminum, copper, lead, and ferrous scrap that would have had to be absorbed by our environment as discards during the period 1965-1990 had they not been recycled totaled more than 2.2 billion tons, just for the four metal groups. Concurrently, huge energy savings were realized and environmental benefits achieved through reduced emissions associated with generating that energy. KEY WORDS: Recycling; metals production; environmental benefits. INTRODUCTION Metals recycling has long been an important component of supply and has in many instances provided solutions to environmental problems (Makar, 1992). The energy savings factors and estimated total energy savings for the cumulative metal recycled during the 1965-1990 period (Powell, 1983) are shown in table 1. Also shown are the energy requirements for production from primary ore, recycled scrap, and the percent energy savings from using scrap (ISRI, 1990). Aluminum scrap yields the largest (96%) energy word 文档 可自由复制编辑 savings of all the commonly recycled metals. A description of the pollution factors associated with this