Continuous Steel Casting Mini-Plant

Continuous steel casting metallurgical mini-plant

• Continuous steel casting metallurgical mini-plant A metallurgical mini-mill is a compact steelmaking plant that runs on scrap metal without blast furnaces. The output capacity of such plants ranges from 20,000 to 1,200,000 tonnes of steel a year.

Production process chain: Charge preparation Scrap metal is sorted and prepared in the scrap yard using loaders, scrap shears, and conveyors. Steel melting Scrap is remelted in an electric arc furnace (EAF) or induction furnace over a period of 45 to 60 minutes. Secondary (ladle) treatment The melt is refined in a ladle furnace unit, where the chemical composition and temperature are adjusted and harmful impurities are removed. Continuous casting Liquid steel passes through a tundish into the mold, where a solid shell of the billet forms and solidifies under secondary cooling. Rolling stage The resulting billets are heated in furnaces and rolled into rebar, wire rod, angle, round, or square sections.

Main continuous casting machine (CCM) equipment:

• Turret - provides continuous metal feed, holding two ladles.
• Tundish - a buffer vessel that stabilizes the metal flow.
• Mold - a water-cooled copper form that shapes the billet shell.
• Mold oscillation mechanism - prevents the metal from sticking to the walls.
• Secondary cooling system - nozzles spraying water or a water-air mixture.
• Withdrawal rollers - pull the billet at a set speed.
• Dummy bar - a starter device that closes the mold before casting begins.
• Torch cutting machine - cuts the continuous billet to the required lengths.

• CCM types:
• Radial (curved):

The most common type, with a low building height, low melt pressure, and high billet quality. The arc radius is 3 to 12 m. Vertical: Has a simple design and good quality but requires a tall building or a deep pit.

Billets produced:

• Square: from 60×60 to 450×450 mm.
• Rectangle (bloom): from 180 mm per side.
• Slab: a flat plate for sheet rolling.
• Round billets for pipes and shafts. Advantages of mini-mills:
• Independence from blast-furnace production.
• Fast start-up and shutdown.
• Flexibility for small-batch runs.