Abstract: A method of controlling operation of a particulate fuel burning boiler, such as a coal fired boiler, having a plurality of burners each receiving pulverized coal, primary air and secondary air. The flow rate of the pulverized coal, primary air and secondary air is determined independently for each burner and is compared with a model. In the event that the comparison results in a determination that one or more of the flow rates depart from the desired rate by a predetermined amount, a control signal is emitted to adjust the air to flow ratio entering the specific burner. The control signal which alters the air to fuel ratio may result in alteration of the air or fuel flow rates. The method may be employed to reduce NOx emissions, loss on ignition and to optimize heat rate.