TABLE OF CONTENTS Next to steel, copper is largest in tonnage and gross value. Used mainly in the electrical/electronics and plumbing industry. Recycle materials are used wire and pipe. Common grades of copper scrap include mixed brass and copper turnings, clips, electronic scrap, some containing precious metals, copper catalysts, copper wire and scrap obtained from discarded sheet copper, gutters, kettles, boilers, etc. Copper is also recovered from copper leach effluents, copper cement, drosses, slags, flue dust and acid plant blowdown slurry or sludge. They will be discussed in Chapters 8 and 9.
The recycling of copper scrap is accomplished either by "direct-use recycling" or by smelting and refining. Direct-use recycling involves the return of the scrap to the original source for reprocessing, for example, brass or tube mills. Brass and bronze scraps generally find their way back to ingot makers who turn the segregated feeds back into casting alloys for resale to foundries. Direct-use recycling eliminates the need for smelting or refining since the scrap is identifiable and will be prepared for reuse in the same application. It accounts for 41 percent of the total consumption in the U.S. and 37 percent in Japan ( CANMET, 1993, p. 63)).
Copper scrap from the electronics, industrial, and communications industries is becoming more prominent and does not lend itself to direct use recycling. Scrap from these sources requires smelting and refining because of the higher concentrations of impurities (precious metals, plastics, and other metals). The collection, sorting and segregation of this scrap...
