Rolling: Process Description

Casting
Heattreating
Mining/Primary Processing
Recycle/Scrap Melting
Aluminum Casting
Aluminum Smelting
Anode Baking
Bauxite Mining
Bauxite Refining
Extrusion
Forging
Heat Treating
Molten Handling
Rolling

Rolling is the process of forming aluminum sheets from slab ingots that are up to 26 inches thick, 20 feet long, and weigh up to 20 tons. The slab is heated in a furnace and rolled between powered rollers until the plate is approximately 1 inch thick. The plates are further reduced in finishing mills where they are hot rolled to a thickness of 0.25 – 0.4 inch.

Equipment
Combustion Technology
Energy Consumption
Process Description

In the pelletizing process, fine ore concentrate is mixed with a binder (bentonite) and formed into green balls in the balling drums. These green balls are then fed into traveling grate kiln furnaces where they are dried and heated and then pass into a rotary kiln for final heating to a point just below fusion (2400°F). The largest furnaces are capable of producing 3.3 million tons of pallets per year.In the sintering process, ore, limestone, and coke fines are mixed and deposited on a traveling grate. Burners ignite the mixture at the feed end of the grate. Air is pulled down through the bed to cause the burning zone to move through the bed until the sintering of the mixture has taken place throughout the entire depth of the bed. The porous, clinker-like sinter is cooled and broken up for use in the blast furnace. The use of sinter reduces coke requirements in the blast furnace, because the limestone is pre-reduced in the sinter bed. Typical daily production from a sinter plant is on the order or 2.3 to 4.4 net tons/sq ft. of grate area.

The Making, Shaping, and Treating of Steel, 10th Edition, Association of Iron and Steel Engineers, 1985.