Present application relates to a mixing device (10) for mixing a first gas with a second gas, the second gas being corrosive to the mixing device. The mixing device comprises a first gas guiding part (12) having a first gas guiding inlet part (14) and a first gas guiding outlet part (16), a second gas guiding part (18) having a second gas guiding inlet part (20) and a second gas guiding outlet part (22), the second gas guiding outlet part arranged in the first gas guiding part so that the first gas and the second gas are mixed and a guide vane configured to establish a swirling motion in the first gas. Further disclosed is a related method.