System and method for thermally treatment of air-dispersible raw material

A method of thermal treatment of air-dispersible raw material comprising:

• introducing the raw material into a conduit through which hot gases flow;
• subjecting the raw material to thermal treatment by the hot gases and/or radiant heat in the conduit, wherein the conduit is a riser conduit;
• converting fuel at least partly in a treatment region;
• supplying, at least partially, heat generated in the treatment region to the conduit, wherein the treatment region and the conduit are connected to each other such that the hot gases are generated in the treatment region by the at least partial conversion of the fuel and flow from the treatment region into the conduit;
• introducing an oxygen-rich gas into the treatment region;
• ascertaining an oxygen content in the hot gas;
• adjusting by open-loop control or closed-loop control, depending on the oxygen content ascertained, an amount of oxygen introduced via the oxygen-rich gas into the treatment region, wherein the oxygen content ascertained is compared with a target oxygen content value, wherein the target oxygen content value is an oxygen concentration between 0% and 6%;
• determining that the oxygen content ascertained exceeds the target oxygen content value;
• and
• in response to determining that the oxygen content ascertained exceeds the target oxygen content value, increasing the amount of oxygen introduced into the treatment region.