Abstract: Method of preparing solid refining agents for the refinement of molten aluminum as well as alloys thereof, and the product of such method. The method comprises a perfect homogenization of components of the agent comprising hexachlorobenzene and a mixture of inorganic salts which latter are dried so as to have a moisture content of 1% by weight of water at most. An amount of from 0.05 to 10 kilograms of discrete bodies of such homogenized mixture is exposed then to a preferably isotactic pressure of from 5 to 150 MPa to form bodies possessing sufficient mechanical strength so as to facilitate the manipulation of the agent and the application thereof into the molten metal. The resulting refining agent is in the form allowing a rational utilization thereof with a high refinement efficiency which is produced by the progressive decomposition of the agent accompanied by the development of chlorine acting as the actual refining agent as well as of other agent constituents to modify its refining effect.