Section 15 BASE METALS AND ARTICLES OF BASE METAL 74 COPPER AND ARTICLES THEREOF 74 01 COPPER MATTES; CEMENT COPPER (PRECIPITATED COPPER). 74 01 00 COPPER MATTES; CEMENT COPPER (PRECIPITATED COPPER). Commodity Code Description 74 01 00 00 COPPER MATTES; CEMENT COPPER (PRECIPITATED COPPER).