PROCESS FOR MAKING MINERAL FIBRES

The present invention provides a process for making a mineral melt comprising: providing a circulating combustion chamber which contains circulating chamber gases, injecting a stream of particulate fuel into the combustion chamber through a fuel feed pipe, injecting combustion gas into the combustion chamber; mixing the stream of particulate fuel with the combustion gas and with the circulating chamber gases by injecting into the combustion chamber secondary gas, through a secondary gas inlet, wherein the secondary gas is injected adjacent to the stream of particulate fuel and the injection speed of the secondary gas is at least 100 m/s greater than the injection speed of the particulate fuel; suspending particulate mineral material in the circulating chamber gases and combusting the fuel, thereby melting the particulate mineral material and forming a mineral melt and hot exhaust gases; and separating the hot exhaust gases from the melt and collecting the melt.