Assessing element distribution and speciation in a stream at abandoned Pb–Zn mining site by combining classical, in-situ DGT and modelling approaches

2015 ◽  
Vol 511 ◽  
pp. 423-434 ◽  
Author(s):  
Dario Omanović ◽  
Ivanka Pižeta ◽  
Petra Vukosav ◽  
Elza Kovács ◽  
Stanislav Frančišković-Bilinski ◽  
...  
Keyword(s):  
Element Distribution ◽  
Mining Site ◽  
Modelling Approaches

Monitoring an in‐situ Uranium mining site with radio tomography

1991 ◽  
Author(s):  
L. Stolarczyk ◽  
W. Mondt ◽  
W. Mays
Keyword(s):  
Uranium Mining ◽  
Mining Site ◽  
Radio Tomography

Trace element constraints on mid-crustal partial melting processes – A garnet ionprobe study from polyphase migmatites (Damara orogen, Namibia)

2009 ◽  
Vol 100 (1-2) ◽  
pp. 205-218
Author(s):  
C. Jung ◽  
S. Jung ◽  
E. Hellebrand ◽  
E. Hoffer
Keyword(s):  
Trace Element ◽  
Secondary Ion Mass Spectrometry ◽  
Element Distribution ◽  
Garnet Growth ◽  
Trace Element Distribution ◽  
Element Abundances ◽  
Diffusion Controlled ◽  
Gradual Variation ◽  
Secondary Ion

ABSTRACTTrace element abundances in garnet from a polyphase migmatite were measured by secondary ion mass spectrometry (SIMS) in order to identify some of the effective variables on the trace element distribution between garnet and melanosome or leucosome. In general, garnet is zoned with respect to REE, in which garnet cores are enriched by a factor of 2–3 relative to the rims. For an inclusion-rich garnet from the melanosome, equilibrium distribution following a simple Rayleigh fractionation is responsible for the decreasing concentrations in REE from core to rim. Inclusion-poor garnet from the same melanosome located in the vicinity of the leucosomes shows distinct enrichment and depletion patterns for REE from core to rim. These features suggest disequilibrium between garnet and the host rock which, in this case, could have been an in-situ derived melt. This would probably indicate a period of open-system behaviour at a time when the garnet, originally nucleated in the metamorphic environment reacted with the melt. In addition, non-gradual variation in trace element abundances between core and rim may suggest variable garnet growth rates. Inclusion-free garnet from the leucosome, interpreted to have crystallised in the presence of a melt, has a small core with high REE abundances and a broad rim with lower REE abundances. Here, crystal-liquid diffusion-controlled partitioning is a likely process to explain the trace element variation.

New developments in sensor technology for water quality surveillance and early warning

2004 ◽  
Vol 50 (11) ◽  
pp. 1-6 ◽  
Author(s):  
S.J. Alcock
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Early Warning ◽  
Sensor Technology ◽  
Metal Mining ◽  
Mining Site ◽  
New Developments ◽  
Field Assessment ◽  
Pollutant Mixtures

Sensor technologies offer particular advantages for surveillance, early warning and process control. This work aimed to provide information about practical new sensing devices that can be used for rapid field assessment of water pollution. A questionnaire completed in 2002 gathered information and data for a catalogue of sensors and instruments that can potentially be applied to soils, sediments, surface and groundwater. Demonstrations of practical sensing technologies took place at a former metal mining site near to Sevilla in 2002, and focusing on diffuse pollution in Koblenz in 2003. These exercises have confirmed that sensors and analytical methodologies can be applied on site to determine various analytes. The instruments provided information useful to manage existing water pollution problems. Some of the scientific innovations of the newest technologies consisted of improved sensitivity, the improved relevance of assays based on biomarkers, the reduced impact on the environment and the capability to detect new contaminants. Sensor technologies were also found to be useful to detect the effects of pollutant mixtures. The portability of these instruments is advantageous for on site and in situ analyses. They will help industry and regulators to deal with existing pollution and attain good water quality.

Use of traditional, modern, and hybrid modelling approaches for in situ prediction of dry matter yield and nutritive characteristics of pasture using hyperspectral datasets

2020 ◽  
Vol 269 ◽  
pp. 114670 ◽  
Author(s):  
Anna L. Thomson ◽  
Senani B. Karunaratne ◽  
Amy Copland ◽  
Danielle Stayches ◽  
Elizabeth Morse McNabb ◽  
...  
Keyword(s):  
Dry Matter ◽  
Dry Matter Yield ◽  
Hybrid Modelling ◽  
In Situ Prediction ◽  
Modelling Approaches

Restoration of Uranium In-Situ Leaching Sites

1980 ◽  
Vol 20 (04) ◽  
pp. 221-227 ◽  
Author(s):  
A.D. Hill ◽  
I.H. Silberberg ◽  
M.P. Walsh ◽  
M.J. Humenick ◽  
R.S. Schechter
Keyword(s):  
Ion Exchange ◽  
New Technology ◽  
Broad Band ◽  
South Texas ◽  
Mining Site ◽  
Solution Mining ◽  
Ore Bodies ◽  
Process Viability ◽  
High Concentrations

Abstract In recent years in-situ leach mining has emerged as a new technology for the recovery of uranium from strata that cannot be mined economically by other means. Because the ore bodies lie within groundwater aquifers, a significant determinant in the process' viability is the requirement that such aquifers be protected from contamination. Since ammonia is one of the constituents of the leach solutions now being field tested, one environmental problem to be resolved is the removal of ammonia at the end of mining. A second related question is the fate of the ammonia that is not removed by the restoration procedure. This paper considers the displacement and migration of ammonium cations in a flowing electrolyte with concomitant ion exchange. The ion exchange is an important feature since, during the solution mining phase, ammonium cations adsorb onto the mineral exchange sites and must be removed from these sites. A mathematical model is used to simulate this process, and the model is tested against the results of laboratory experiments. It is found that the simulations are adequate if an appropriate selection of parameters is made. The model then is used to simulate restoration procedures and to determine the rate of migration of unrecovered ammonium in the groundwater. It is concluded that ammonium removal can be accomplished best using high concentrations of a cation that is exchanged selectively relative to ammonium cation. Introduction In-situ solution mining is a process rapidly being developed for the recovery of uranium from sandstone ore bodies. This mining technique is applicable when the uranium ore is too deep, too small in extent, or of too low a grade to justify using conventional mining techniques. Such ore bodies are numerous in south Texas, occurring along a broad band of the U.S. gulf coastal plain. The solution mining process being used in Texas is primarily an alkaline leach. The sandstone ores that may be solution-mined occur in aquifers, and the uranium is in the insoluble +4 state of oxidation. To be mobilized, the uranium must be oxidized to the +6 state and then complexed with carbonate ions to form the highly soluble uranyl dicarbonate or uranyl tricarbonate ions. Thus, alkaline leach solutions contain an oxidant (usually hydrogen peroxide) and a mixture of carbonates and bicarbonates. To minimize formation damage, most solution mining now employs ammonium carbonate/bicarbonate as the carbonate source. These solutions have been found effective in dissolving the uranium minerals found in south Texas sandstone ores.1 However, the restoration of the mining site is also a primary consideration. Since the ore bodies that can be solution-mined occur in aquifers, government regulations require that water quality at the mining site not be degraded below the quality that existed at the inception of mining. Furthermore, the permitting procedures require that groundwater restoration be completed at one site before the next site on a particular lease may be mined.2 Obviously, environmental aspects will be an important consideration governing the success of in-situ solution mining.

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