The aim of this study is to improve electrical conductivity properties of the 99.6% commercial aluminium with high concentration of principal transition elements of 0.013% Ti, 0.011% V, and 0.006% Cr compared to standard requirements of the 99.7% EC-grade aluminium T-bars used in continuous-casting lines to manufacture feedstock for aluminium conductor. However, this type raw material can be supplied easily in huge quantities from the aluminium smelters on region of the north of the Black Sea and the Caspian Sea under low premium, it is impossible to use them directly in CCL to manufacture aluminium conductor. To investigate usage possibility of them the intended experimental works has been executed in three stages at CCL. After having completed several experiments, the optimum treatment procedure was determined. Each samples taken from EC-grade 99.7%, 99.6% aluminium as supplied and 99.6% aluminium, inoculated by aluminium-boron alloys in the phases of 5% AIB(12), 4% AIB(12), and 3% AIB(2) have been examined in SEM/EDX. (c) 2004 Elsevier B.V. All rights reserved.