Resources.-Since World War II, the
ever-increasing reservoir of copper
products has satisfied between 19% and
33% of annual U.S. apparent industrial
consumption in the form of old scrap.
By 1993, this domestic reservoir of-
unreclaimed products contained over 70
Mmt of copper. While some of this
copper has been disposed in landfills or
dissipated to the environment and is not
readily recovered, as much as 70% of
this copper is still in use or abandoned in
place, and hence theoretically available
for recycling. Dissipative uses of copper,
principally as copper chemicals,
constitute only about 0.5% of current
copper demand.   It is estimated that
between   30%   and   50%   of   the
unrecovered products have been disposed
in landfills.
Estimation of the recycling efficiency
for copper is complicated by the varied
life cycle of its different end uses and by
trade in manufactured products containing
copper. Copper in electrical plants and
machinery averages 30 years; in
nonelectrical machinery, 15 years; in
housing, 40 or more years; and in
transportation, 10 years. In 1992, the
recycling efficiency for copper (old scrap
consumed divided by the quantity of old
scrap theoretically available using average
product sector life-cycles, and adjusted
for net scrap trade) was estimated by the
U.S. Bureau of Mines to be about 30%.
This ignores net trade in copper contained
in manufactured and semimanufactured
products. By the same calculations, if all
the copper that was theoretically available
from old scrap were recycled in the
United States, old scrap could account for
almost three-fourths of domestic apparent
consumption.   In  1993, old scrap
accounted for only 22 % of apparent
consumption.  The rate of old scrap
recovery is limited not only by copper's
long life and its essential uses, but also
by the sensitivity of scrap collection to
market prices.
New (manufacturing) scrap, on the
other hand, has a short life, about 30
days, and its recovery is limited by
domestic  manufacturing  rates  and
efficiencies.  This wide difference in
turnaround and availability has resulted in


a gradual increase of new scrap versus
old scrap as a component in all scrap
collected in the United States.
Technology.-Because of the variety
of grades and alternative routes to
recycling, an elaborate infrastructure has
developed to collect, upgrade, and
process copper-bearing scrap prior to
shipment to the consumer. For example,
copper cables and wires, a prime and
valued source of higher grades of
unalloyed scrap, must be processed
manually or through sophisticated
chopping operations, to remove unwanted
insulation.  While chopped wire is
shipped in barrels, stripped cable and
other bulky scrap must be sheared and
baled to facilitate transport and feed to
secondary smelters. Previously, burning
of the cable to remove insulation and
other combustibles prior to recycling was
acceptable; environmental regulation of
emissions now generally precludes this.
While No. 1 copper may be consumed
directly (remelt) or processed through a
refinery, No. 2 copper generally requires
refining  before  it  is  consumed.
Low-grade scrap is generally processed
through   multi-step  smelting  and
electrolytic refining to produce refined
copper, though some, such as electric
circuit board scrap, may be treated
hydrometallurgically to produce chemical
products such as copper sulfate and
copper oxide. Electrolytically refined
secondary   copper   is   generally
interchangeable with primary refined
copper and is suitable for wire and cable
manufacture. While lower grades of
alloy scrap may be processed through
smelting, higher grades of sorted scrap
are directly consumed (direct melt) in the
production of copper alloy products.
Processing complex copper-containing
materials, such as drosses, flue dust,
catalysts, slimes from electroplating waste
water, and metal-rich slags from
converter processes requires a versatile
production process. Secondary smelters
use a three-stage smelting process similar
to that employed in primary processing:
a first stage primary smelting blast or
reverberatory furnace, followed by a
converter and anode furnace. Depending


on grade, scrap may enter the flowstream
at any of the three furnaces.
Alloy copper scrap may be directly
consumed at ingot makers, brass mills, or
foundries and miscellaneous
manufacturers. The scrap is melted in
reverberatory  or  electric  induction
furnaces, and impurities are skimmed off
as dross. Pure metal or master alloy
ingots may be added to adjust the
composition of the melt before casting
into slabs, ingots, billets, etc., or various
foundry products.
Economic Factors.-Copper scrap
prices are closely correlated to the price
of refined copper. However, the price
paid for scrap at each level of processing
must be sufficiently discounted to allow
for all subsequent processing costs.
Thus, a scrap collector who must perform
such functions as sorting, shipping,
chopping, baling, etc. will pay less for
scrap than does the consumer. Because
of these inherent costs associated with the
initial collection and processing of scrap,
low refined copper prices will squeeze
processing and profit margins and reduce
the quantity of scrap that can be
economically recovered.  The spread
between refiner's buying price for No. 2
scrap and refiner's selling price (producer
price) for refined copper has varied from
9 cents in 1970 to over 30 cents in the
late 1980's. The low spreads in the early
1970's were caused by price controls
placed on U.S. copper during this period.
The very high spreads of the late 1980's
were the result of high refined copper
prices and a good supply of scrap.
Structural and Environmental
Factors.-Domestic   production  and
consumption of brass and bronze ingot,
products from copper-based scrap,
declined markedly between the late
1960's and early  1980's owing   to
substitution of aluminum and plastics for
brass and bronze castings, increased
import penetration, and the imposition of
environmental control regulations on both
ingot makers and the consuming
foundries.  Over that time period,
domestic production of alloy ingot fell by


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