Temporal Observations of the Geochemistry and Mineralogy of a Sulfide-rich Mine-tailings Impoundment, Heath Steele Mines, New Brunswick

Abstract Since the 1957 initiation of deposition of mill tailings at the Heath Steele mine, New Brunswick, periodic detailed studies of the tailings geochemistry and mineralogy have been conducted, thereby providing a unique opportunity to examine the geochemical evolution of a sulfide-rich mine-tailings impoundment. When deposited, the tailings contained about 85 wt sulfide minerals, 1 wt to 3 wt carbonate minerals, and 12 wt to 14 wt aluminosilicate minerals. Mineralogi-cal examination of samples of the tailings from deep in the impoundment indicates that little oxidation occurred prior to tailings deposition. The mill process-water deposited with the tailings was neutral to slightly basic and contained low concentrations of Cu, Pb, Zn and As. Sampling of the tailings five years after deposition indicated that sulfide-oxidation reactions, occurring near the tailings surface, had decreased the tailings-water pH and increased the concentrations of Fe, SO42~, Cu, Zn and Pb (up to 10 000 mg/L, 25 000 mg/L, 2.5 mg/L, 200 mg/L, and 4.5 mg/L, respectively). In 1975, ten years after decommissioning, the tailings could be divided into three zones: an upper oxidation zone in which sulfide oxidation is actively occurring, a hardpan layer, 15 cm to 20 cm thick, composed of tailings cemented by secondary Fe minerals, and an underlying reduction zone in which the tailings are relatively unoxidized (Boorman and Watson, 1976). Chemical analyses indicated the presence of low-pH waters containing very high concentrations of SO42-, Fe, and other metals (up to 63 600 mg/L SO42 , 28 600 mg/L Fe, 10 mg/L Pb, 600 mg/L Cu and 4000 mg/L Zn), suggesting that there was a period of intense sulfide oxidation between five and ten years after tailings deposition. More recent sampling, conducted some 20 years after the end of tailings deposition, indicates that relatively little change has occurred in the last ten years, thereby suggesting that the hardpan layer has provided an impediment to the downward movement of dissolved constituents. Analyses of the tailings solids show increased accumulations of many metals at or near the depth of the hardpan layer. Evaluations of the long-term evolution of the tailings can be enhanced by comparison of descriptions of the tailings with descriptions of the gossan that overlay the massive-sulfide orebody prior to mining. At Heath Steele, this comparison suggests that many of the mechanisms controlling the distribution of metals in the tailings will probably persist over geologic time.
Full Access to Technical Paper
PDF version for $20.00
Search
Sort By:  Relevance
Showing results 1 - 8
Text
Summary: A well-defined approach is essential to ensure the long-term success of a regional exploration program. Teck's approach in eastern Canada is designed to fulfill corporate objectives while recognizing certain unique parameters for exploration in the area. The elements of this approach include clearly defined objectives, technical considerations and personnel policies, all of which are equally important. The goal is a significant discovery before the mid-1990s and the company is confident that...
Publication: Exploration & Mining Geology
Author(s): BARRY D. SIMMONS
Issue: 3
Volume: 1
Year: 1992
Text
Summary: Perhaps the single most significant variable in the evaluation of a mining project is the reserve estimate. Many parameters are considered when estimating reserves, among them geology. This paper examines the link between the quality of a reserve estimate and a good understanding of the geological controls for the deposit. A clear understanding of the geometry is essential to the accurate definition of the shape and size of the deposit. This includes the definition of any structural controls...
Publication: Exploration & Mining Geology
Author(s): CHRIS M. HEALEY
Issue: 3
Volume: 1
Year: 1992
Text
Summary: Detailed sampling using a portable diamond drill, and interlaboratory comparison of selected samples have been combined with statistical studies of truncated populations to establish the gold content of several outcrops in the Val d'Or area. The outcrops chosen are non-mineralized. The background gold concentration in the rocks of the region is 5 ppb or less. Gold is distributed relatively homogeneously within the outcrops studied except for slightly increased concentrations within quartz-tou...
Publication: Exploration & Mining Geology
Author(s): TYSON BIRKETT, FRANCOIS ROBERT, DAN RICHARDSON, STEVE GREEN
Issue: 3
Volume: 1
Year: 1992
Text
Summary: The rare-earth elements (REE) form a significant part of the group of so-called "high-technology" metals whose glamour has attracted both the scientific community and the mining industry. Despite this attraction, world production of REE declined abruptly in 1985 and only recently has begun to approach production levels of 1984. The decline in 1985 was primarily due to decreased demand for light REE used as catalysts in the production of lead-bearing gasoline. Incorporated within the current...
Publication: Exploration & Mining Geology
Author(s): W.D. SINCLAIR, J.L. JAMBOR, T.C. BIRKETT
Issue: 3
Volume: 1
Year: 1992
Text
Summary: The Orion gold mine, located 7 km northeast of the town of Malartic, Quebec, was discovered in mid-1985. Underground exploration was undertaken in 1986 leading to commercial production in 1988. The upper part of the orebody was exploited above the 125 m level and a total of 131 090 t at an average grade of 5.31 g/t gold were extracted.
This paper describes the authors' current knowledge and interpretation of the geology, gold distribution, and structure of the Orion No. 8 ore zone deposit....
Publication: Exploration & Mining Geology
Author(s): YVON TRUDEAU, DENIS RAYMOND SOQUEM
Issue: 3
Volume: 1
Year: 1992
Text
Summary: The Kipawa yttrium-zirconium prospect is located about 150 km south of Noranda, , Quebec. Yttrium-zirconium mineralization occurs in an elongate, regionally metamorphosed and deformed peralkaline complex in the Grenville terrain. The mineralized zone, as defined by >0.10% Y2O3, is 1300 m long and 10 m to 30 m wide. Zirconium content typically ranges from 0.50 to 1.20% ZrO2. The mineralized zone strikes northwest and dips 20 degrees to 35 degrees to the southwest. It occurs at the structural...
Publication: Exploration & Mining Geology
Author(s): JAMES F. ALLAN
Issue: 3
Volume: 1
Year: 1992
Text
Summary: The Orostar and Scadding were two small gold mines owned and operated by Orofino Resources Limited. Conventional statistical treatment indicates an identical arithmetic mean grade of 0.22 oz/T Au for both mineable reserves. Further, the deposits are both shown to have cut weighted average reserve grade of 0.21 oz/T. Orostar mined out at 0.206 oz/T and Scadding at 0.156 oz/T Au. The combined exploration and development database contained 1394 fire assays, more than enough for statistical...
Publication: Exploration & Mining Geology
Author(s): FRANCIS T. MANNS, ELAINE ELLINGHAM
Issue: 3
Volume: 1
Year: 1992
Text
Summary: Biotite from aplite that appears to have crystallized simultaneously with disseminated Cu-Mo mineralization at MacLeod Lake in northern Quebec yields K-Ar dates in the range 2032 ± 44 Ma to 2097 ± 47 Ma. The mean value, 2065 Ma, is some 400 Ma younger than the 2485 ± 64 Ma date obtained from a hornblende concentrate separated from a granodiorite sill that is spatially, but apparently not genetically, associated with the disseminated Cu-Mo deposit. The mean biotite date of 2065 Ma at MacLeod...
Publication: Exploration & Mining Geology
Author(s): J.F. DAVIES, G.J. PRIOR
Issue: 3
Volume: 1
Year: 1992
Powered by Coveo Enterprise Search