Browsing by Author "Vauclin, M"

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    Acid leaching of copper in a saturated porous material: Parameter identification and experimental validation of a two-dimensional transport model
    (ELSEVIER SCIENCE BV, 1997) Munoz, JF; Rengifo, P; Vauclin, M
    In this study, a two-dimensional mathematical solute transport model is proposed to simulate the leaching of copper ore tailings using sulfuric acid as the leaching agent, injection wells to introduce the leaching agent, and pumping wells to retrieve the pregnant copper leach solution. To calibrate the model, a tracer experiment and a leaching experiment were performed, both under conditions of a single-direction flow pattern established between two boundaries of constant height. These experiments enabled the model hydraulic, dispersion and reaction parameters to be determined. Validation of the model was performed by comparison of the numerical results given by the model with experimental results obtained from a second leaching experiment, performed under conditions of a radial flow pattern established through the use of four injection wells and one pumping well and making use of the parameters estimated previously during the calibration process, The comparison between predicted and measured leaching behavior was good (20-22% error). The study has significant implications for applications related to the use of the proposed numerical model for predicting the performance of in-situ soil washing alternatives. (C) 1997 Elsevier Science B.V.
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    In situ acid leaching of copper tailings deposits
    (2001) Muñoz, JF; Rengifo, P; Suazo, A; Shackelford, CD; Vauclin, M
    The results of a field-scale study involving in situ leaching of copper ore tailings using sulphuric acid as the leaching agent, injection wells to introduce the leaching solution and extraction wells to recover the copper-enriched pregnant leaching solution are presented, The study was performed at an abandoned tailings disposal site using a battery of injection and extraction wells. The medium was characterized through the determinations of physical, chemical, mineralogical, and hydrodispersive properties based on laboratory and field tests, including a tritium tracer test, a pumping test, particle size analyses, and hydraulic conductivity tests. Numerous horizontal strata with different hydraulic conductivities were identified. A previously developed model was used to simulate the leaching of copper ore tailings. Although the study confirms the feasibility of using in situ leaching for recovery of residual copper from tailings deposits, the efficiency of the technology depends significantly on the medium stratigraphy and hydraulic conductivity.
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    Opus simulation of water dynamics and nitrate transport in a field plot
    (ELSEVIER SCIENCE BV, 1999) Bonilla, CA; Munoz, JF; Vauclin, M
    In this paper, Opus, an agricultural contaminant transport model, was used to simulate a year of soil water flow and nitrate transport as well as crop growth for an arable cultivated soil, near Grenoble, France. This study is explicitly related to the cultivation of irrigated maize, a major crop in the area. The results have shown that, in terms of water balance, the simulations of water flow match the general measured trends. Drainage and evapotranspiration were estimated with errors of 4 and 20%, respectively. Runoff estimation was exactly accurate. Nitrogen movement and nitrogen concentration in the root zone were simulated well, and the cumulative leach beyond the root zone was estimated with an error less than 11%. The results for crop growth were good. Some reasons for these results are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.