No description available.

Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 142-146). Also available in electronic format on the Internet.

A geochemical study of the composition of natural sediments and contaminating mine tailings in Hastings and Alice Arms has been carried out. Apart from the geochemical investigation on the solid fraction, pore waters from six sediment cores have been analyzed to evaluate the diagenetic processes in the sediments of these two inlets. Differences in the mineralogy as well as in the chemical composition of the sediments were used to distinguish the natural sediments from contaminated sediments and pure tailings. In Alice Arm, two types of tailings could be differentiated with these methods. The first tailings type originated from the Kitsault Mo-deposit, which was mined in the past two decades by the B.C. Molybdenum Corporation and AMAX/Canada. These tailings are characterized by a number of features which make them distinguishable from natural sediments. The K-feldspar content of the tailings is significantly increased, mainly at the expense of plagioclase, which is the main characteristic for the mineralogical identification of this tailings type. The enhanced K-feldspar content is the cause for increased K and Rb values in the Mo-mine tailings. Another indicator specific to these recent tailings is an increased Mo content. The second tailings type is derived from an older mining operation in the Kitsault Valley, most likely the Dolly Varden Silver Mine. A specific indicator for these tailings is their high Ba content which is due to large amounts of barite. This mineral phase could be identified by X-ray diffraction methods in a heavy mineral fraction of the relevant sediment layers. Both tailings types show enrichment in their Pb, Zn and S concentrations, caused by an increased amount of metal-sulphides in the ore materials. In this area, these elements can therefore serve as a general indicator for the contamination of natural sediment with either tailings type. The interstitial water analyses indicated that the sediments in both inlets become reducing at a fairly shallow depth (10-15 cm), resulting in the mobilization of Mn, Fe and Mo from the solid phase. In the deeper parts of the cores, consumption of these metals could usually be observed which is likely due to precipitation of authigenic components. The dissolved Mo concentrations in the sediments contaminated with the modern tailings were much higher than in the natural sediments. In the pore water of the pure tailings the concentration reaches some 300 times that of the overlying water, which is the highest value ever reported for saline pore waters. These high Mo concentrations must support a flux of Mo from the sediment into the overlying water, and it is shown that such a flux could increase the inventory of naturally occurring dissolved Mo in the deep waters of Alice Arm by up to 4%. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

No description available.

No description available.

Mine tailings result from surface mining coastal plain soils and sediments and are redeposited in a slurry form to the mined area. Mine tailing contains a low amount of organic matter, a low pH, and a high P fixation capacity. This research was carried out in the Atlantic Coastal Plain region to determine if mine tailings reclamation could be accomplished by utilization of yard waste compost and wood ash. Yard waste compost was used to increase the organic matter content and wood to increase pH of the mine tailings. Field research was conducted to determine the effect of yard waste compost and wood ash incorporation into mine tailings on (Zea mays L.) and peanut (Arachis hypogaea) yields. Levels of yard waste compost applied to the mine tailings were 1, 2, 4, 6, 8, and 12% by weight, and wood ash was applied twice at a rate of 2.4 t ha⁻¹. Increases in corn and peanut yields on the mine tailings were attributed to increased available water from the application of yard waste compost and to increased pH from the application of wood ash. Successful use of the yard waste compost and wood ashes for reclamation of the mine tailing is shown by the higher peanut yields on the tailings soils than adjacent natural soils. Although the corn grain yields were relatively high (up to 7830 kg ha⁻¹) where yard waste compost and wood ash were applied to the tailings, the overall corn grain yields were higher on the adjacent natural soil. Probable reasons for lower corn grain on the tailings were inadequate available water at times of maximum need and N and/or P deficiencies. Zinc deficiency was induced in corn plants by the high level of P fertilization required to overcome the high P fixation capacity of the mine tailings. The Zn deficiency could be corrected by either foliar or broadcast-disk in application of ZnSO₄. / Master of Science

[Truncated abstract] As mineral deposits continue to be mined, the non economic gangue materials such as sulphides (e.g. pyrite) that are extracted as part of the ore body or overburden are deposited within the waste rock and/or milled tailings. As a result of natural weathering processes, these reactive materials represent a potential hazard to surrounding environments. A major consequence, resulting from mine-waste impoundments containing sulphidic materials, relates to the offsite movement of low pH leachates containing elevated concentrations of metal ions posing a contamination threat. The processes and mechanisms acting in the formation of acid mine drainage (AMD) are highly variable and, to a high extent, controlled by climatic conditions as the main driver of water flow and wetness of the system which in turn determines the availability of oxygen as well as water for pyrite weathering. In particular, this thesis is based on the hypothesis that in semiarid and arid climates the acid production may be water … The experiments were repeated at different water contents ranging from 0.24 to 0.33 cm3 cm-3. Breakthrough curves (BTC) of Li+, K+, Ca2+, Mg2+, Na+ and pH were measured and described with models of different complexities. This included the use of a simple linear and non-linear isotherms for Li+ alone, a binary Li+ - K+ ion exchange, and a complete multicomponent chemical equilibrium description of ion transport. The latter, by including dissolution of primary minerals which released base cations such as Mg2+, Ca2+ and K+ explained some of the elution patterns of base cations for which the Li+ - K+ exchange was the dominant process. Furthermore, under unsaturated water flow conditions, retardation of Li+ increased with decreasing water content. Thus solute mobility in mafic rock tailings appears to decrease under strongly unsaturated water flow conditions.

One hundred surface sediment samples and two 30 cm cores were collected from Howe Sound, British Columbia, a deep (≈280 m) fjord with a restricted inner basin into which mine tailings had been dumped for 75 years. The abundances of major elements Si, Al, Ti, Fe, Mg, Ca, Na, K, C, N, and P, and minor elements Ba, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V, Y, Zn, and Zr were determined as well as nutrient and trace metal concentrations in porewater from the two cores. The solid-phase data suggest that the inner basin sediments are dominated by Squamish River-derived feldspars, while the outer basin is characterized more by quartz and Fe and Mg minerals, which enter the southernmost portion of the fjord via estuarine circulation from Georgia Strait. Although Fe, Cu, Pb, Zn, and Ba are still enriched in sediments near the tailings outfall, the lapse of 13 years since cessation of tailings deposition has apparently resulted in reduced metal levels throughout much of the rest of the inlet due to ongoing dilution by natural sedimentation. Profiles of these metals with depth show that the tailings deposit proper is buried by ≈14 cm of natural sediment in the deep central portion of the inner basin. Porewater analysis of the two cores revealed that active bacterial remobilization of organic matter is occurring at both locations; although the organic carbon content of the outer basin is greater than that in the inner basin, sulphate-reduction is more intense in the latter due to the higher sedimentation rate. Despite this, dissolved sulphides were nearly absent in porewaters, leading to the conclusion that authigenic pyrite precipitation is removing some of the dissolved Fe. Dissolved Cu and Zn are enriched in surficial porewaters of both the outer and inner basins (i.e. Cu = 215 and 132 nmol/L, respectively, and Zn = 32 µmol/L and 1.6 /µmol/L), but decrease rapidly within the top 2-3 cm, suggestive of active removal by some mechanism. Dissolved Pb concentrations were low (<3 nmol/L) in both cores, and did not show any surface enrichment. These data suggest that a strongly reducing environment such as is found at depth in natural sediments inhibits the release of some labile metals which may be contained within them. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Research was conducted at Cyprus Pima Mine, an open pit copper mine located southwest of Tucson, Arizona, in 1980 and 1981 to study the establishment of annual and perennial grasses on the slopes of copper mine tailing ponds. In 1980, the north and south slope exposures were hydroseeded with barley (Hordeum vulgare L.). Plots were capped with topsoil prior to planting or left uncapped, and mulched with wheat straw after planting or left unmulched. Desert soil was classified as Palos Verdes-Sonoita Complex and Detrital-Sonoita Complex. Barley provided a quick, temporary cover and served as a mulch for later plantings. The number of seedlings established was the same for both exposures. Barley grew taller on the north slope possibly due to cooler temperatures. Barley growth was more vigorous on mulched areas. In 1981, the same north and south slopes were hydroseeded with Lehmann lovegrass (Eragrostis lehmanniana Nees.), buffel grass (Pennisetum cilare (L.) Link), blue panicgrass (Panicum antidotale Retz.) and bermudagrass (Cynodon dactylon (L.) Pers.). Prior to planting perennials, barley residue was incorporated into the slopes using a spike-tooth chain drag and a sheepfoot roller, or was left unincorporated. Incorporation of barley residue aided in its breakdown and helped prepare a good seedbed. The spike-tooth chain drag produced better growth than the sheepfoot roller, possibly due to excessive soil compaction with the sheepfoot roller. Capping tailing slopes with desert soil produced the most significant improvements in barley and perennial grass growth. Soil analyses of pure tailing and capped tailing revealed both were low in nitrogen and phosphorus. All plots were amended with these nutrients. Organic matter, although low for both samples, was higher in the capped tailing sample. Organic matter improves soil structure and provides nutrients and its increased presence may have been the main reason for improved growth on capped slopes.

The commercial mining of asbestos occurred in four Provinces of South Africa (Northern Cape, North West, Limpopo and Mpumalanga). It was initiated in the late 1800's and lasted for over a hundred years into the beginning of this century. As a producer of amphibole asbestos, South Africa far outpaced every other country being responsible for 97% of global production. The last crocidolite mine closed in 1996 and chrysotile in 2002. Anecdotal information concerning environmental contamination as a result of the former mining activities and the improper disposal of mine waste tailings has been reported by a variety of authors. Few comprehensive or systematic surveys have been conducted to date to document this issue and very little quantifiable research has been completed on the communities located in close proximity to the former mine sites to determine the extent of contamination. In 2004-2006 communities were surveyed within the Northern Cape and North West Provinces to determine the extent and severity of environmental contamination. This research developed and applied a methodology to select those communities suspected of environmental contamination, a targeted survey methodology, and a protocol for rapid sample laboratory analysis. A total of 41 communities were initially predicted by the model to be suspected for environmental asbestos contamination. Based on the inclusion of local knowledge, a final 36 communities were selected for a screening-level field assessment, 34 of which were found to contain environmental asbestos contamination at rates ranging from 20 to 100% of the surveyed locations. A total of 1 843 samples of soil and building material were collected in the screening level assessment. One community (Ga-Mopedi) was selected as being representative of the total cohort and a more detailed house to house survey was completed. A total of 1 486 samples were collected during the detailed survey. Results of the detailed survey revealed 26.2% of the homes were contaminated with asbestos containing soil and/or building material. A theoretical quantitative cumulative exposure assessment was developed to estimate the disease burden within the study area population of 126,130 individuals within the surveyed communities resulting in a predicted range of 25-52.4 excess deaths per year from lung cancer and mesothelioma due solely to environmental exposures to asbestos pollution.