METHOD OF REFINING OF ALUMINUM AND ITS ALLOYS Russian patent published in 1997 - IPC

FIELD: refining of aluminum melts from impurities, for instance, of alkali metals, hydrogen and nonmetallic inclusions. SUBSTANCE: the offered method includes treatment of melt with flux, blowing with gas and filtering. Flux and gas are introduced in combination under the level of melt. Filtering is carried out under conditions of metal laminar flow. Flux and gas are introduced in ratio of (6-15):1 by specific flow rate, and metal flow rate at filter outlet is not in excess of 0.001 m/s. Application of combined supply of gas and flux excludes enveloping of bulb of gas-flux mixture with oxide film and continuous introduction of this mixture to under melt level contributes to more full and stable use of gas-flux mixture for refining from impurities, both, due to absence of oxide film on bubble surface and larger surface of contact of regent with melt, and also due to constant composition of supplied mixture and sufficient distance between bubbling zone and filter surface assists in suppression of turbulence in moving flow of melt and its feed to filter surface with flow velocities corresponding to laminar nature of motion. EFFECT: higher degree of refining of aluminum melts and reduced duration of refining process due more full use of gas and flux treatment of melt and provision of the most efficient conditions of filtration. 3 cl, 1 dwg, 1 tbl