Reagent selection and optimization-the case for a holistic approach

Historically, the process of reagent selection and optimization has been rather informal, reductionistic and frequently based on extension of personal experience from one mineral system or plant to another, gut feeling, anecdotes, and myths. There is no recognized “standard” practice, and the informal process is fraught with pitfalls. The complexity and variability in mineralogy and the complex interactions between chemical, physical-mechanical and operational factors in the plant are invariably ignored in such an approach, and the selected reagent will have a narrow, un-optimized window of performance. Thus the chemical solution to a plant's demand will not be robust. This approach is also very costly in the long run and adds little to our knowledgebase. In this paper an expanded holistic view of the flotation system is described, and a rational, holistic process is discussed for reagent selection, optimization, and profitable implementation in the plant, using base metal sulfide flotation system as an example. Although such an approach in the flotation system may, at first glance, imply impracticality, an attempt is made in this paper to show that a manageable holistic approach can be practiced and that it is necessary in order to develop robust solutions to metallurgical needs in the plant.