Method and apparatus for monitoring and analyzing the surface of floated material

Abstract

At the separation of different minerals from the ores by means of flotation, it belongs to known art to monitor a larger part of the uppermost froth layer in the flotation cell by means of a video camera whose signals are analyzed in a digital computer, in order to detect the structure and color of the froth. The new method and apparatus direct and limit the monitoring and analysis to the surface of the floated material within a fixed, narrow strip which is parallel to the overflow edge of the cell and within which the material surface passing it is homogeneous in the stationary state. The said strip thus presents a renewing sample of the surface at the location in question, which sample represents the stationary state in the average sense. The strip is subjected to homogeneous illumination, which may meet the strip at different angles depending on the primary object, i.e. whether the color or structure is being determined. By means of a repeatedly reading semiconductor line array camera, the image of the strip is formed and converted to electric black/white or multicolor signals from which the structure or color quantities are determined in digital computer. The monitoring and analysis can be directed to both the surface of the froth layer and the surface of the froth slurry flowing down from the overflow edge.