El medio ambiente en la minería

115 PER G. BROMAN CorrespondingIy, emissions of particulates and metals to the air have been sharply reduced. The relationship between the emission level al the close of the 1%Os and at present are illustrated in a bar graph in figure 3. The demonstrably heavy reductions have been achieved through the installation of filters and, not least, through the development of effective monitoring and maintenance routines for these filters. Worth noting in this context is the development and installation of selenium filters for the removal ofmercury. I <E- elrlld 11115-18 =:1 ( uu.a o Figure 3: The Ronnskar works. Emission lo air of metals and sulphur dioxide •• deveJopment from the late '60s to the early'90s. Major efforts have aIso been focused on reducing discharges of contaminants to waterways. Here, the contributing factor has been the construction of a water-treatment planto In the plant, sedimentation of partic1e-bound metals occurs. The dissolved metals are then precipitated as sulphides. The sedimen– tary material and the precipitate are recycled to the copper line's roaster following dewatering. Figure 4 illustrates the considerable effect these measures have had on dischargesofcontaminants. The reduction in discharged contaminants general1y exceeds 90 percent.