The characteristic properties of waste rock piles in terms of metal leaching
| Autor: | Mike O'Kane, Lindsay Tallon, Eben Sy Dy, Kidus Tufa, Kevin A. Morin, Cody Meints, Liang Ma, Zhong Xie, Mike Aziz, James Zhou, Elizabeth A. Fisher, Zhong-Sheng Liu, Cheng Huang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Canada
Scaling law Materials science 0207 environmental engineering Thermodynamics 02 engineering and technology 010501 environmental sciences 01 natural sciences waste rock piles rate control quotient chemistry.chemical_compound scaling laws Environmental Chemistry Water Pollutants 020701 environmental engineering Groundwater Dissolution 0105 earth and related environmental sciences Water Science and Technology solute production potential Rate control Models Theoretical Volumetric flow rate Metal leaching chemistry Metals metal leaching Pile Characteristic property Saturation (chemistry) rate control mechanisms |
| Zdroj: | Journal of Contaminant Hydrology. 226:103540 |
| ISSN: | 0169-7722 |
| DOI: | 10.1016/j.jconhyd.2019.103540 |
| Popis: | Surface/ground waters could be polluted when rain-water and/or snow-melt water infiltrate through waste rock piles at mine sites and dissolve secondary minerals (salts) from rock surfaces. It is important to reduce solute loading by the optimal configuration of waste rock piles. This requires the proper definition and determination of the characteristic properties of waste rock piles in terms of metal leaching and, in particular, rate control mechanisms and scaling laws, and their dependence upon configuration variables. For revealing these characteristic properties this paper proposes a pile-scale C-Q relation: C = Cs(1 − e-P/Q), (P ≡ kλβψ), where C and Cs are respectively solute concentration and particle's saturation concentration, Q is the flow rate of the water through a waste rock pile, k represents the effective or average dissolution coefficient of a mineral specie from rock surfaces, β represents rock pile depth, λ represents the ratio of the sum of the surface areas of rocks to the volume that the rocks occupy, and ψ is the sum of the cross-sections of water-flow channels in a waste rock pile. The two characteristic properties revealed by the C-Q relation are: (1) P, the product of k, λ, β, and ψ (P ≡ kλβψ), which is the characteristic property of a waste rock pile in terms of metal leaching, named here the solute production potential; and (2) the ratio of P to Q, P/Q, a non-dimensional number, designated as α (α ≡ P/Q), named here the rate control quotient, which is the scaling law and the rate control mechanism indicator. The value of α quantitatively indicates what controls the rate of mineral dissolution, and it also relates smaller-scale metal-leaching testing results to their corresponding full scales. When α becomes small, say α 2.5, solute concentration would become close to its saturation concentration Cs, and Q determines solute loading (that is, the solute loading is proportional to Q). When 0.5 |
| Databáze: | OpenAIRE |
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