A metal separation process, comprising the following steps: + introducing the metal to be separated together with a liquid into a reactor; + adding process gas reacting with the metal to be separated and mixing; + recovering the metal to be separated, characterized in that the mixing of liquid and process gas is achieved by means of the "surface effect gassing" method and - gas is introduced via at least one gas inlet above the maximum filling level of the reactor and discharged via at least one gas outlet above the maximum filling level of the reactor; - the liquid is introduced via at least one liquid inlet and discharged via at least one liquid outlet, wherein the discharging is preferably effected via the bottom of the reactor; - the liquid is stirred with a stirrer; - wherein homogeneous stirring in of the process gas is allowed via at least one flow interrupting means (baffle) in combination with the stirrer; wherein the metal to be separated is precipitated from a solution containing the metal to be separated in the form of the metal or a metal salt; and wherein gold is precipitated, the process comprising the following steps: (i) introducing an aqueous gold solution into a reactor via at least one liquid inlet, (ii) sealing the reactor, (iii) exchanging the gas in the headspace by a process gas which comprises SO 2, wherein the gas is introduced via at least one gas inlet above the maximum filling level of the reactor and discharged via at least one gas outlet above the maximum filling level of the reactor, (iv) stirring the mixture, resulting in a self-aspirated gassing of the mixture according to the method of surface effect gassing, wherein a homogeneous stirring in of the process gas is allowed via at least one flow interrupting means (baffle) in combination with the stirrer, (v) adding additional process gas, as required, (vi) completing the conversion, if SO 2 is no longer consumed, (vii) cooling/warming to room temperature, (viii) recovering the gold. + introducing the metal to be separated together with a liquid into a reactor; + adding process gas reacting with the metal to be separated and mixing; + recovering the metal to be separated, - gas is introduced via at least one gas inlet above the maximum filling level of the reactor and discharged via at least one gas outlet above the maximum filling level of the reactor; - the liquid is introduced via at least one liquid inlet and discharged via at least one liquid outlet, wherein the discharging is preferably effected via the bottom of the reactor; - the liquid is stirred with a stirrer; - wherein homogeneous stirring in of the process gas is allowed via at least one flow interrupting means (baffle) in combination with the stirrer; (i) introducing an aqueous gold solution into a reactor via at least one liquid inlet, (ii) sealing the reactor, (iii) exchanging the gas in the headspace by a process gas which comprises SO 2, wherein the gas is introduced via at least one gas inlet above the maximum filling level of the reactor and discharged via at least one gas outlet above the maximum filling level of the reactor, (iv) stirring the mixture, resulting in a self-aspirated gassing of the mixture according to the method of surface effect gassing, wherein a homogeneous stirring in of the process gas is allowed via at least one flow interrupting means (baffle) in combination with the stirrer, (v) adding additional process gas, as required, (vi) completing the conversion, if SO 2 is no longer consumed, (vii) cooling/warming to room temperature, (viii) recovering the gold.