4 resultados para Boron isotopes
em Digital Commons - Montana Tech
Resumo:
Since 1911, at which time, the age hardening phenomenon of duralumin was discovered by Film, much research has been carried on investigating the various alloy systems. The successful application of age hardening to the copper aluminum system (duralumin) has indicated the possibility of hardening practically all the metals in the same way.
Resumo:
Boron is an element whose metallurgical possibilities have never been fully investigated. The principal reason for this fact seems to lie in the difficulties encountered in preparing elemental boron and its various intermetallic compounds.
Resumo:
Many attempts have been made to improve iron and steel and their alloys by the addition of boron. The results obtained were not encouraging for the reason that the amount of boron used, generally from 0.2 to 2.0 per cent is altogether too high. This percentage of boron renders the product hard and brittle and of late the experiments with boron in this connection have been practically abandoned.
Resumo:
The Continental porphyry Cu‐Mo mine, located 2 km east of the famous Berkeley Pit lake of Butte, Montana, contains two small lakes that vary in size depending on mining activity. In contrast to the acidic Berkeley Pit lake, the Continental Pit waters have near-neutral pH and relatively low metal concentrations. The main reason is geological: whereas the Berkeley Pit mined highly‐altered granite rich in pyrite with no neutralizing potential, the Continental Pit is mining weakly‐altered granite with lower pyrite concentrations and up to 1‐2% hydrothermal calcite. The purpose of this study was to gather and interpret information that bears on the chemistry of surface water and groundwater in the active Continental Pit. Pre‐existing chemistry data from sampling of the Continental Pit were compiled from the Montana Bureau of Mines and Geology and Montana Department of Environmental Quality records. In addition, in March of 2013, new water samples were collected from the mine’s main dewatering well, the Sarsfield well, and a nearby acidic seep (Pavilion Seep) and analyzed for trace metals and several stable isotopes, including dD and d18O of water, d13C of dissolved inorganic carbon, and d34S of dissolved sulfate. In December 2013, several soil samples were collected from the shore of the frozen pit lake and surrounding area. The soil samples were analyzed using X‐ray diffraction to determine mineral content. Based on Visual Minteq modeling, water in the Continental Pit lake is near equilibrium with a number of carbonate, sulfate, and molybdate minerals, including calcite, dolomite, rhodochrosite (MnCO3), brochantite (CuSO4·3Cu(OH)2), malachite (Cu2CO3(OH)2), hydrozincite (Zn5(CO3)2(OH)6), gypsum, and powellite (CaMoO4). The fact that these minerals are close to equilibrium suggests that they are present on the weathered mine walls and/or in the sediment of the surface water ponds. X‐Ray Diffraction (XRD) analysis of the pond “beach” sample failed to show any discrete metal‐bearing phases. One of the soil samples collected higher in the mine, near an area of active weathering of chalcocite‐rich ore, contained over 50% chalcanthite (CuSO4·5H2O). This water‐soluble copper salt is easily dissolved in water, and is probably a major source of copper to the pond and underlying groundwater system. However, concentrations of copper in the latter are probably controlled by other, less‐soluble minerals, such as brochantite or malachite. Although the acidity of the Pavilion Seep is high (~ 11 meq/L), the flow is much less than the Sarsfield Well at the current time. Thus, the pH, major and minor element chemistry in the Continental Pit lakes are buffered by calcite and other carbonate minerals. For the Continental Pit waters to become acidic, the influx of acidic seepage (e.g., Pavilion Seep) would need to increase substantially over its present volume.