Journal of the Southern African Institute of Mining and Metallurgy
versão On-line ISSN 2411-9717
GROOT, D.R. e PISTORIUS, P.C.. Can we decrease the ecological footprint of base metal production by recycling?. J. S. Afr. Inst. Min. Metall. [online]. 2008, vol.108, n.3, pp. 161-169. ISSN 2411-9717.
Sustainability and the environment are important and topical themes currently. There is a generally growing awareness of resource consumption, possible resource depletion, and the polluting effects of indiscriminate dumping at the end of the useful life of an item, as well as of the pollution caused by producing items and making them available to the end user. The issues are complex and interlinked. In order to improve understanding, it is important to obtain holistic and quantitative perspectives. To help in quantification, concepts such as the ecological and carbon footprints have been defined and are in common use. This paper introduces the concept of a material footprint to help quantify the material resource usage in an item, in terms of globally available resources. It allows comparison of various items to one another in terms of their use of material resources. Thus the types of items available for recycling can be ranked to determine recycling priorities. The material footprint can also help in determining recycling priorities for the various materials in the items. Several examples are used as illustration. It is shown that recycling of printed circuit boards is especially worthwhile. Printed circuit boards are complex and heterogeneous from a materials recycling perspective. The paper describes the complexities of recycling these boards, but also points out the benefits. An overview is given of currently available metallurgical technologies for such recycling. It is shown that in these processes there are many factors that affect the environment. It thus remains difficult to determine the total impact of recycling on the environment holistically. Possibly some benefits are to be gained in the Southern African context by better integration between secondary material processors and primary metal producers.