Abstract: A method of increasing the chemical recovery capacity of a Kraft Recovery Furnace by injecting solid pellets of sodium sulphate and sodium carbonate directly onto the char bed in the reducing zone of the furnace while maintaining the temperature and reducing atmosphere in this zone thereby to form a smelt containing sodium sulphide and sodium carbonate from the injected pellets. These pellets may be produced from a further quantity of balck liquor in an auxiliarly incinerator such as a fluid bed combustion unit. This invention permits increasing the recovery capacity of a furnace without necessitating the construction of a new Recovery Furnace.