Microwave Technique for the On-Line Determination of Unburnt Carbon in Fly Ash

The CSIRO Division of Mineral and Process Engineering has developed a microwave technique for the on-line determination of unburnt carbon in fly ash from coal-fired power stations. A laboratory evaluation of the technique has been made using 20 fly ash samples from six New South Wales and Queensland power stations. The unburnt carbon has been determined over the range 0.1-12 wt% carbon, with r.m.s. errors in the range 0.08 to 0.28 wt% for individual power stations. A plant trial of industrial prototype gauges will be conducted at a New South Wales power station during 1990.