Applications of Leaching and Precipitation Modeling in Nickel Hydrometallurgical Process Design

Abstract

Mathematical modeling of heterogeneous, two and three phase reactors in hydrometallurgical processes is not new. However, that does not mean that it is yet easy to do, nor that it is common practice. Piloting remains the method of choice for testing new processes or modifications to existing processes. Nevertheless, there may not always be budget available for expensive pilot testing, so that process designers and process operators turn to modeling as an investigative tool and use model results to plan a test program that is more cost effective (confirmatory rather than investigative) and can be completed in a much shorter period of time. This paper presents a simple yet rigorous method of modeling heterogeneous,
two and three phase reactors in Excel using the classic Population Balance Model approach. The application and usefulness of the model will be demonstrated with three examples taken from nickel hydrometallurgy: nickel sulphide precipitation, gypsum precipitation during acid neutralization, and pressure oxidative leaching of nickel sulphide. The ability to interface the model with other process design tools such as METSIM® and OLI will also be demonstrated.