Source: Midwest Research Institute. Economic studies in support of policy formation on resource recovery. Unpublished data, 1972.

make corrugated boxes), and $20-30/ton for printing/writing paper. The latter cost differential is the result of substantial upgrading of waste paper that would be required to produce a product of the present high standards. The cost of newsprint manufacture, however, is lowered by using 100 percent recycled fiber (deinked newsprint). This has been the only major new market for waste paper in recent years.

The economics of constructing new mills based on either virgin or secondary fibers also supports industry's trend toward use of more virgin fiber at the expense of secondary fiber. An analysis of folding boxboard (combination board made from secondary fiber vs. solid wood pulp board made from virgin pulp) found the return on investment from a virgin based plant to be 8.1 percent while that for a plant based on waste paper (combination board) was only 4.5 percent.5 Under such circumstances, investments in new combination board mills are very unlikely. The reason for the shift in recent years of boxboard manufacture from combination board mills to virgin based mills is obvious.

FERROUS METALS RECYCLING

Status and Trends

Ferrous solid waste (primarily in the form of food and beverage containers and discarded consumer appliances) constitutes 7 to 8 percent of collected municipal solid waste and totalled roughly 14 million tons in 1970. However, a much more sizable amount of used and discarded ferrous products (an estimated 38-54 million tons) is generated annually and appears on our landscape in such

visible forms as abandoned automobiles, discarded farm implements, out of service rail cars, construction and demolition waste, and other steel products."

In 1967 American industry consumed about 83.5 million tons of iron and steel scrap and 7.6 million tons were exported (Table A-5). The domestic scrap consumption represented about 65 percent of the raw steel production (Fig. A-3). Fifty million tons of this domestic scrap consumption was "home" scrap that was generated in the iron and steelmaking process and was fed back into the furnaces. Excluding home scrap and exports, 35 million tons of scrap, or about 20 percent of the iron and steel consumption, was recycled in 1967.

For the past 25 years, scrap as a percent of total metallic input to steelmaking has remained essentially constant. However, the amount of this scrap purchased by the steel industry (originating from outside the steel plant) has been decreasing slightly while that generated within the steel mills has increased. As shown in Fig. A-4, purchased scrap as a percent of total scrap input to steelmaking has decreased from 44.9 percent for the period 19491953 to 40.0 percent from 1964-1968. In absolute terms while total steel production increased 35 percent over the period 1950-1969, and total scrap consumption increased 30 percent, scrap purchased increased only 8 percent.

Sources

There are two basic types of iron and steel scrap, "home" and "purchased."

"Home scrap", the ferrous waste product generated during iron and steel production, includes ingot croppings, sheet trimmings, and foundry gates and risers. Being generated in the steel mill, the scrap is of known composition and purity, and the total amount generated is normally consumed. Home scrap represented 60 percent of the domestic scrap consumption in 1967.7

Source: Darnay, A., and W. E. Franklin. Salvage markets for materials in solid wastes. Washington, U.S. Government Printing Office, 1972. p. 49 and 58-11.

Source: Darnay, A., and W. E. Franklin. Salvage markets for materials in solid wastes. Washington, U.S. Government Printing Office, 1972. p. 58-1 and 58-11.

Source: Darnay, A., and W. E. Franklin. Salvage markets for materials in solid wastes. Washington, U.S. Government Printing Office, 1972. p. 58-11.

"Purchased" scrap is further classified as "prompt" or "ob

solete."

"Prompt" industrial scrap is generated by metal working firms in their fabrication of products. Standard procedures have been developed for the recycling of prompt scrap and it never really enters the waste stream. At least 90 percent of the available prompt scrap is estimated to be recycled. The scrap is desirable because of its known composition, condition, and freedom from contaminants. In addition, it is considered a reliable material source because the quantities available are predictable and recycling channels have been established. Prompt scrap represented about 16 percent of the domestic scrap consumption in 1967.8

"Obsolete" scrap comes from discarded iron and steel products. Major sources are structural steel from building demolitions, ships, railroad equipment, and abandoned motor vehicles. Ferrous waste, of course, occurs in many other forms such as food and beverage cans and home appliances which are not generally recovered due to logistics, contamination, or other factors. Obsolete scrap represented about 25 percent of the domestic scrap consumption in 1967.9

Not all of the steel consumed flows immediately into the waste stream and is available as scrap. Considerable portions go into semi-permanent use (buildings, machinery, etc.) and enter the waste stream years later. It is estimated that the 21.6 million tons of obsolete scrap purchased or exported in 1967 was 43-56 percent of that available in the solid waste stream. Taking into account scrap located in remote locations and probably not recoverable and scrap disposed of by individuals, it is estimated that roughly another 24-39 million tons of ferrous scrap could feasibly have been recovered in 1967.10

Markets

The major markets for iron and steel scrap are the domestic steel industry, the domestic foundry industry, and exports. In 1969, the percentage of total scrap consumption by each was 73.8, 17.5 and 8.7 respectively.11 However, in terms of purchased scrap (prompt and obsolete) foundries and exports weigh more heavily. For the steel industry about 35 percent of scrap consumed is purchased, while foundries purchase about 60 percent of their scrap consumption, and exports are naturally purchased scrap.

The American steel industry is composed of approximately 110 companies of which 21 are fully integrated (coke ovens, blast furnaces, and steelmaking furnaces), 9 operate mostly blast fur