Resumo (PT):
Apresenta-se um modelo matemático baseado na fenomenologia da lixiviação por percolação.
O modelo é composto por um sistema de equações diferenciais onde todos os parâmetros têm um significado físico preciso, sendo possível a sua determinação em laboratório.Diferentes simulações revelaram uma forte concordância entre os resultados do modelo e os resultados experimentais.
Abstract (EN):
The first mathematical dissolution models were developed as early as 1846 for very simple
and idealised situations. Since then, many other models have been developed, generally using semiempirical
relationships. A new mathematical model totally based on the phenomenology of leaching
is proposed. Formally, the model is a distributed parameter system where all the parameters have a
precise physical sense which allows to measure them physically in a laboratory.
The model consists of a three first order partial differential equations system, the first
describing the space-time evolution of the concentration of the leaching agent. The second one
outlines the behaviour of the metal in the solid phase in the same domain, and the last one describes
the variation of the concentration in metal transferred from solid phase to liquid as a consequence of
the depletion in the leaching agent.
The physical reality undoubtedly defines both the initial and the boundary conditions. It also
suggests a chained integration sequence and the applicability of numerical methods.
Because there is not a known analytical solution for the system of PDE, numerical methods - finite
differences were used. The stability of the solution was studied in detail as a function of discretization
of the domain.
The simulations performed using the model showed a high agreement when compared to
experimental data, proving its robustness.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
9
Tipo de Licença: