Economic impact of spargers degradation in flotation columns

Abstract Flotation is a very complex process, where many variables interact to produce different metallurgic results. These characteristics pose a challenging problem to evaluate the economic impact of deviations of a normal condition. For example, what is the value of a calibration plan to assure the quality of a measurement of froth depth in a cell? Specific experiments designed to evaluate this deviations cannot be implemented in practice, since there are many independent variables changing simultaneously with unknown values. In this paper a methodology applied to estimate the economic impact of spargers degradation in flotation columns is presented. Four pieces of information are required. First, we need to express the association of the deviation from a normal condition with specific characteristics of process variables. In this case how the change in orifice diameter in the sparger affects the air bubble size distribution produced. Second, we need to relate this physical change with the process metallurgic. One way of doing this is to develop a phenomenological model that includes the effect of such variable. Third, we need to relate the metallurgical losses to economic losses. In this case we need to know how the metallurgic changes will affect the value of a concentrate and the extra cost of posterior treatment due to the changed characteristics of this product. Finally the information of how fast a sparger is degraded over time is needed. The methodology is applied to an industrial flotation column, discussing the assumptions made because of the lack of some precise information. The idea is that in spite these uncertainties, at least the most conservative economic evaluation can be made. If one need more precise evaluation to make decisions, then the characteristics of the extra information needed and how to obtain it in an industrial environment is suggested.