Figure 5. T.K. Sherwood empirically identified a relationship between the selling prices of materials
and their dilution (or degree of distribution in the initial matrix from which they are separated). The
diagonal line denotes this empirically observed linear relationship. The data points indicate the
minimum concentration of metals wastes typically recycled as a function of metal price. Points lying
above the line indicate the existence of metals in wastes typically not recycled even though their
concentration exceeds those found in virgin ores. Source: Allen, D.T. and Behamanesh, N., 1994,
Wastes as Raw Materials, pp. 68-96 in The Greening of Industrial Ecosystems, Allenby, B.R. and
Richards, D.J., eds., National Academy Press, Washington, D.C..[Key for chemical symbols:
As-arsenic, Ag-silver, Ba-barium, Be-beryllium, Cd-cadmium, Cr-chromium, Cu-copper,
Hg-mercury, Ni-nickel, Pb-lead, Sb-tin, Se-selenium, Tl-tellurium, V-vanadium, Zn-zinc]