Software sensors, digital imaging based, for flotation froth supervision: algorithms and procedures

Integrated hardware and software (HW&SW) solutions are very cheap and easy to implement at industrial level in many sectors. These innovations can thus be profitably applied in the field of mineral processing and more specifically in flotation processes, especially adopting new processing detection strategies and analysis of flotation froth features oriented to analyze both the whole and the single flotation froth characters. In this perspective new procedures can be successfully applied to carry out quite "simple" and "easy-to-apply" determinations and new control actions on routine bases, both at laboratory ("off-line" control) and processing plant scale ("on-line" control). The possibility to utilize new analytical "on-line" digital imaging techniques in the field of flotation can open new horizons. To successfully reach these goals, several conditions, linked with the particular nature of the samples (froth images) have to be verified: the adoption of specific sampling procedures (easy and correct acquisition of the images necessary for the analysis); the identification of those parameters that extracted from the images can describe the characters concerning the froths (morphological and morphometrical parameters, color and/or textural information); the procedures able to extract the characters of interest from the images (points, lines, 2D and 3D analysis); the identification of a correct target-oriented-processing-strategy to manipulate and process the previous extracted characters; the synthesis of the results and the definition of one or more correlation functions able to establish a correspondence between digital information, extracted from the images, and bulk materials handling and processing; the definition of suitable control strategies, at a different level of interaction/s with the process/es, to apply specific control action on the process itself. In the paper will be analyzed, described and discussed the guidelines that can be considered at the base of the definition of digital based procedures for flotation froth processing and handling. The considerations will be developed with particular reference to the case of industrial flotation plant operating in steady state conditions.