Industrial demonstration of a sensor for monitoring coal flotation

[Display omitted] •A low-cost sensor was developed for monitoring coal flotation performance.•The sensor measures drag exerted by the overflowing froth using two strain gauges.•Excellent diagnostic performance of the sensor was demonstrated by on-site trial. This paper presents a simple new sensor for real-time monitoring of coal flotation. The sensor was developed based on measurement of the drag exerted by the overflowing froth onto a cantilever beam. The effectiveness of this sensor for flotation monitoring was demonstrated by an on-site trial in a coking coal flotation plant in Queensland, Australia. The trial was carried out using one of the full-scale column flotation cells in the plant for five days, with the froth depth being fixed at 1.0 m but frother dosage and aeration rate being varied over a wide range. The output of the drag sensor had a strong linear correlation with the clean coal yield (mass recovery), with the coefficient of determination being 0.97.