Improving grade control efficiency with rapid on-line elemental analysis

Flotation circuit control is typically based on regular on-line elemental analyses. In base metal applications the conventional assaying method is X-ray fluorescence (XRF), which has proven to be a reliable and accurate technology. However, in large flotation plants with many sample streams to be analyzed, the measurement frequency for individual assays decreases because a centralized XRF analyzer can only measure one stream at a time. This results in unnecessary delays that reduce the control performance. Nevertheless, by integrating reflectance spectroscopy measurement with the conventional XRF technology, a practically continuous assay can be obtained. In this paper the advantages of improved analysis cycle to process performance via faster automated higher level flotation circuit control are demonstrated. The presented technology enables capturing and reacting to grade fluctuations that may have been missed with longer measurement intervals. Moreover, response time to drastic changes in flotation circuit operation is significantly reduced which results in better process performance.