General Process Flow
Tangga Power Plant l Transmission Lines l
Smelting Plant : Carbon Plant - Reduction Plant - Cast House
Siguragura and Tangga Power Plants are located along Asahan river. The power generated by both power plants is transmitted to the Smelting Plant in Kuala Tanjung through 271 units of transmission lines. Through Inalum Substation in Kuala Tanjung, the power is then distributed to the reduction buildings and others with 2 (two) units of Silicon Rectifier with DC 37 kA and 800 V.
The raw materials of aluminium are unloaded at INALUM's port and loaded to silos with belt conveyor. The alumina in the silo is flowed to Dry Scrubber System to be reacted with HF from reduction cells. The reacted alumina is charged to Hopper Pot by Anode Changing Crane (ACC) and poured into reduction cells.
Cokes in the silo are mixed with butt and preheated. Those materials are mixed with pitch as binder. Those materials are shaked in the Shaking Machine to be green anodes. Those green anodes are then baked into Baking Furnace. Those baked anodes are then transported to Anode Rodding Plant. Those anodes are attached with rods, named Anode Assembly.
Those anode assemblies are transported to Reduction Plant by a special car, Anode Transport Car (ATC) to be used as electrodes in the electrolysis process. Having been used for around 28 days, the rest of anodes, called butt will be changed with new anode assembly. Those butts are then pressed and crushed in the Rodding Plant to be used as new anodes.
In the reduction cells, the alumina will be electrolized and each pots will produce molten aluminium. Every 32 hours, each pot will be tapped for 1.8 to 2 tons of molten aluminium. The molten aluminium will be transported to Casting Plant by Metal Transport Car (MTC) and charged into Holding Furnace. Having been processed, the molten aluminium is then cast into Casting Machine to be Aluminium Ingot, 22.7 kg each. The aluminium ingots are then bundled and are ready to be marketed.