Pyrolysis and combustion of polymer wastes in combination with metallurgical processes and the cement industry

Various industrial metallurgical processes in which polymer wastes occur, either as undesired impurities or which are added purposely as fuel or as reduction agents are summarized. At the moment, a major route for the use of polymer wastes is in the blast furnace for steel-making. Here, the plastics are substituted for some of the coke, coal, or oil that is used for reduction of the ore and for heating. Other processes in iron-making where the use of polymer wastes has been proposed are based on several varieties of the electric-are furnace technology. In non-ferrous metallurgy, polymer wastes disturb the secondary melting and, if non-ferrous metals are contaminated with polymer wastes, special precautions must be taken. The recycling of electronic scrap is particularly problematic. Polymer wastes also find use in cement industries, but exclusively as a fuel. (C) 1999 Elsevier Science B.V. All rights reserved.