A self-cooled oxidant-fuel burner consisting novel fuel and oxidant nozzles and three compartment refractory burner block design is proposed. The new oxidant-fuel burner can fire in high-temperature (2200° F. to 3000° F.) and high-particulate (or high process volatiles/condensates) furnaces without over-heating or causing chemical corrosion damage to it's metallic burner nozzle and refractory burner block interior. Using various embodiments of nozzle and block shape, the burner can offer a traditional cylindrical flame or flat flame depending on the heating load requirements. The new features of this burner include unique fuel nozzle design for the streamline mixing of fuel and oxidant streams, a controlled swirl input to the oxidant flow for desired flame characteristics, a controlled expansion of flame envelope in the radial and axial dimensions, and efficient sweeping of burner block interior surface using oxidant to provide convective cooling and prevent any build up of process particulates. In addition, a relatively thick wall metallic nozzle construction with heat conduction fins enable efficient heat dissipation from the nozzle tip and providing a maintenance free burner operation.