A burner for combusting a metal containing powder, particularly iron powder, comprising a combustion chamber having a combustion space for holding a combustion flame during operation, the combustion chamber having at least one air inlet, a powder inlet, and at least one exhaust gas outlet, wherein the combustion chamber has a re-circulation channel for recirculating exhaust gases that leads back to the combustion space via at least one return channel within said combustion chamber, in that the powder inlet opens into said return channel, and wherein said at least one air inlet opens into said return channel downstream of said powder inlet.