Environmental Case Study: Smelter Emissions

ACIDIC EMISSIONS SO2 + OH + ozone + H2O2 = H2 SO4 REACTION WITH CARBONATES = GYPSUM H2 SO42- + CaCO3 = CaSO4. H2O + CO2

The International Smelter is a reclaimed mill site, now a Utah State wildlife preserve, southwest of Salt Lake City, at the base of the Oquirrh mountains, east of Tooele. The site was reclaimed in the late 1980s and now is covered with grass and low bushes, except in areas where milling artifacts still remain. This site contained heavy-metal sulfide smelters which operated from 1910-1971 and had at least two smokestacks. It is hypothesized that sulfur dioxide and other volatiles emitted from the processing of the sulfide ores were blown to the northeast and east and reacted with the atmosphere as shown above, thereby creating acid precipitation conditions which resulted formation of certain clays and gypsum. These acid-generated minerals suppress the growth of vegetation, as seen in the picture at right. Field reflectance spectroscopy and hyperspectral images were used to map distribution of this environmental impact.

These images show the distribution of potential smelter emissions at the International Smelter site. The site is shown in the AVIRIS image in [A]. The yellow arrow shows the prevailing wind direction. The stacks were located near [Sm], slag heaps are at [Sg], tailings dikes at [Dk], and the potential emission impacts at [E]. SFSI-2 (SWIR Full Spectrum Imager) images show distribution of gypsum, product of SO2 interaction with [C] dolomitic host rocks. Acid-generated clays (kaolinites) are shown in image [D] in blue and green, grading into more neutral illites and smectites in red and yellow.

Aerial overview of the smelter complex, showing the slag dump at lower left, Dry Canyon at upper center, and the smokestacks for the copper and lead smelters in center. Looking slightly west of south. Date uncertain, but probably in early 1960s. ("Photograph from the Wilbur H. Smith Papers (MS563), Special Collections, J. Willard Marriott Library, University of Utah")

View of smelter complex emissions at full production, including lead and copper smelters in operation. Looking northeast. Taken May 5, 1914. Note patterns of smoke plumes. ("Photograph from the Wilbur H. Smith Papers (MS563), Special Collections, J. Willard Marriott Library, University of Utah")

This case study is part of a NASA-sponsored project, evaluating hyperspectral remote sensing techniques as applied to mine waste characterization. It is also part of the EPA Region 8 Utah AML (Abandoned Mine Lands) Project.