Mining & Metallurgy

Mining & Metallurgy

 In this experiment, Author validated experimental data with the chemical kinetic model. No significant difference has been observed in the degree of reduction on the type of coal used as the reducing agent. The activation energy was higher (124.71 KJ) while choosing coal as a reducing agent than the coal + coal dust as a reducing agent (59.75 KJ). The highest reaction rate constant was observed at 1000°C. Abnormal swelling was noted at 850 and 900°C, whereas shrinkage was noted at 950 and 1000°C. A variety of modeling techniques can be utilized to forecast metal production at heap leaching operations. These approaches reflect a wide range of complexity, flexibility, time to implement, cost, and accuracy. For many operators, a spreadsheet-based modeling technique is attractive since the calculations are directly accessible, models can often be developed by site staff, and the results are generally easy to extract and interpret. The authors have developed a spreadsheet-based modeling technique that provides a high degree of flexibility, while still considering detailed operating information for ore properties, leach kinetics, scale-up factors, lift height, and in-heap metal inventories. The technique involves establishing kinetic leach curves for each ore type to characterize metal extractions, followed by application of separate metal recovery curves to define the rate at which leached metals exit the heap in pregnant solution, taking into account delays due to the in-heap solution inventory. At any point in time, the difference between total metal extracted and total metal recovered is equal to the in-heap inventory of the leached metal. This modeling technique is particularly useful for larger multi-lift heaps where delays in metal recovery are appreciable due to in-heap solution holdup. The technique is also applicable to sites with multiple heaps, leach cycles, and/or metal recovery plants (e.g., carbon columns for gold; solvent extraction for copper). This paper describes the modeling technique, including input data required and methods for defining kinetic leach curves and metal recovery curves. The technique is compared against an alternative spreadsheet technique using a simplified in-heap solution inventory calculation to forecast metal production, which has proven to be effective at a number of sites.


Last Updated on: Nov 26, 2024

Global Scientific Words in Bioinformatics & Systems Biology