Old scrap

The initial step in the recycle of metals is the physical segregation of the metals from other materials. Eor new scrap this process is straightforward for old scrap it can be expensive. This classification and segregation of scrap is of importance to the producers of the metals from secondary materials. Historically, much of the classification has rehed on hand sorting which can be rehable, but it is labor intensive. The recycling of automotive scrap is illustrative of the... 

Copper. Domestic mine production of copper metal in 1994 was over 1,800,000 t. Whereas U.S. copper production increased in the 1980s and 1990s, world supply declined in 1994. There are eight primary and five secondary smelters, nine electrolytic and six fire refiners, and fifteen solvent extraction—electro winning (SX—EW) plants. Almost 540,000 t/yr of old scrap copper and alloy are recycled in the United States accounting for - 24% of total U.S. consumption (11). New scrap accounted for 825,000 t of contained copper. Almost 80% of the new scrap was consumed by brass mills. The ratio of new-to-old scrap is about 60 40% representing 38% of U.S. supply. 

Secondary Recovery. Metal returning from the store of metal in use is referred to as old scrap, in contrast with scrap generated within the copper fabrication process, which is called new scrap (see Recycling). In 1990 the amount of the U.S. copper supply derived from old scrap was 24% of the total copper consumed. About 40% of old scrap is used for producing refined copper most of the remainder is used in the production of brass and bronze ingots (see Copper alloys). About 75% of new scrap is consumed by brass mills, with most of the remainder used in the production of refined copper. Some estimates suggest that as much as 60% of the copper produced is ultimately recycled for reuse. Old scrap combined with new scrap from fabricating plants accounts for about 40% of the metallic input to domestic copper furnaces. 

The secondary production of lead begins with the recovery of old scrap from worn-out, damaged, or obsolete products and with new scrap. The chief source of old scrap is lead-acid batteries other sources include cable coverings, pipe, sheet, and other lead-bearing metals. Solder, a tin-based alloy, may be recovered from the processing of circuit boards for use as lead charge. 

The degree of availability of recyclable resources such as scrap and wastes is a widely varying parameter. By way of illustration, scrap can be classified as new scrap (or in-process scrap) and old scrap (or post-consumer scrap). The former, which constitutes the majority of scrap processed at present, is derived mainly from the wastes generated during metal production and fabrication, and can be reclaimed and recycled with relative ease. 

New scrap is generally of high grade, is generated in large amounts at few locations, and can thus be easily collected and sorted. Old scrap, on the other hand, is generally of a lower... 

Of recycled, or secondary copper, 56% is derived from new scrap, while 44% comes from old scrap. Domestically, the secondary copper smelting industry is led by four producers. Like the secondary aluminum industry, these producers buy the scrap they recycle on the open market, in addition to using scrap generated in their own downstream productions. The secondary copper industry is concentrated in Georgia, South Carolina, Illinois, and Missouri. 

For the most part, the zinc materials recovered from secondary materials such as slab zinc, alloys, dusts, and compounds are comparable in quality to primary products. Zinc in brass is the principal form of secondary recovery, although secondary slab zinc has risen substantially over the last few years because it has been the principal zinc product of electric arc furnace (EAF) dust recycling. Impure zinc oxide products and zinc-bearing slags are sometimes used as trace element additives in fertilizers and animal feeds. About 10% of the domestic requirement for zinc is satisfied by old scrap. 

Since 1951, silver consumption has exceeded its extraction from ore. Secondary silver production involves the recovery of silver from new and old scrap, resulting from silver-containing wastes generated by industry and the consumer. Recycled silver accounted for 40% of U.S. refinery production in 1971 and had increased to 67% by 1974 (Smith and Carson 1977). It was estimated to be 61% and 56% in 1988 and 1989, respectively (The Silver Institute 1990). The estimated world-wide recovery of silver from the photographic industry is about 67% of the total used (The Silver Institute 1988). It has been estimated that 80%, 68%, and 75% of today s annual consumption by the electrical, industrial-alloy, and art industries, respectively, is recycled silver, but these estimates may be high. 

In 1997, domestic primary aluminum production totaled just over 3.6 million metric tons (7.9 billion pounds. Thirteen companies operated 22 primary aluminum reduction plants, and 1 plant remained closed. Montana, Oregon, and Washington accounted for 38% of the production Kentucky, North Carolina, South Carolina, and Tennessee, 21% and other States, 41%. Aluminum recovered in 1997 from purchased scrap was almost 3.5 million metric tons (7.7 billion pounds), of which 50% came from new (manufacturing) scrap and 50% from old scrap (discarded aluminum products) (USGS 1997a, 1998, 1999). 

In the United States, about 40% of the lead used is recovered from scrap. There are two types of scrap lead. The term old scrap applies to metal that has already been used in some manufactured object and the used article has been recycled for resmelting. Lead in the form of pieces cut off, filings, turnings, and so forth discarded during manufacturing processes is called new scrap. Automobile batteries constitute the largest source of old scrap lead. 

Fig. 12.2 Production of primary aluminium in the US between 1930 and 2001 has risen dramatically the contribution that recycled aluminium has made to the market became increasingly important in the latter part of the twentieth century and competes with primary production. The term secondary aluminium refers to metal recovered from new and old scrap, and the total production is the sum of primary and secondary sources. [Data US Geological Survey.]...

Collection rate (CR) (also old scrap collection rate) gives the amount of a metal contained in end-of-life (EOL) products that are collected and transferred to recycling routes. 

Old Scrap Recycling for the U.S. Pcst-ccnsumer waste available as % of apparent supply ... 

Old scrap as percent of supply. (USGS Circular 1196. Row Studies for Recycling Metal Commodities in the United States ... 

RE application Estimated RE stocks in 2020 (tons) Estimated average lifetime (years) Estimated RE old scrap in 2020 (tons)... 

Within the metal industries it has been common practice for many years to recover a range of metals and alloys from secondary materials. Secondary materials consist of old scrap and new scrap, such as wastes, ashes, drosses and residues, with old scrap by far the more significant. The importance of secondary recovery for any metal depends mainly on two factors firstly, the type of major end-uses for the metal, and, secondly, the scale and efficiency of recovery facilities available. For a number of reasons which will be discussed, the recycling of secondary materials is far more important in the lead industry, than for any other of the major non-ferrous metals. Over half of total lead consumption in the Western World now represents metal recycled from scrap and other secondary materials. This compares with between 20-40 per cent for the other main non-ferrous metals. ... 

With old scrap representing in excess of 90 per cent of the total. 

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