A kinetic model for heap leaching of uranium ore considering variation of model parameters with depth of heap

Many kinetic models for heap leaching of low grade ores have been proposed and the model parameters have been treated as constants. However, some of these model parameters change with the depth of the heap. In the present work an apparatus consisted of six columns with different heights was designed and used to simulate the leaching behavior within a 3-m-high uranium ore heap at a uranium mine in South China. It was found that the model parameters α and ω for heap leaching of the uranium ore varied with the depth of the heap, and that the relationships between α and between ω and the depth of the heap were in the form of the logistic and the quadratic functions, respectively. Furthermore, a kinetic model for heap leaching of the uranium ore considering the variation of the model parameters with the depth of the ore was proposed. The kinetic model gave the fitting precision of more than 95 % and prediction precision of more than 93 %. The present work provided an approach for establishing the kinetic model for heap leaching of low grade uranium ores.