Mobarakeh Steel Company

The planning for steel manufacturing was started in 1975. The project originally was started in Bandar Abbas and five years later it was transferred to Esfahan. Due to political turmoil, no activity took place until 1980.

Production processes: overview

MSC's iron ore (raw material) comes from mines in Golgohar and Chadermaloo (Kerman and Yazd provinces) and are converted to pellets in the pelletizing plant (diameters: 8–10 mm). After being reduced in the direct reduction (DR) plant and removed of oxygen, pellets are converted to (sponge iron). Sponge iron and iron scrap is melted in electric arc furnaces, after which liquid steel is purified in secondary purification units. The steel's chemical compound is designed by customer demand. Then, it is transported to casting machines for slab production. After cooling, slab is rolled at the hot rolling mill, creating hot coils (thickness: 1.5–16 mm). Some are sold; others go to the hot finishing mill for complementary work and hot sheet transformation or the cold rolling mill to lower strip thickness to 0.18 mm. Cold rolled coils are also dedicated for the tinning, galvanizing, and prepainting lines.

Iron plant complex

The iron plant complex has 10 main production line units (the rest are auxiliary and back up units). Iron ores with large grains from Golgohar are converted by ball mills in the Pelletizing plant. After mixing with Chadermalou's smaller grains and bentonite in blending machines it is changed to pellets (diameter: 6–25 mm) and screened by a two-story roller screen. Pellets solidify in an induration tunnel or furnace at 1280 °C. The Lime Production Plant receives limestone from the Hozmahi mine, which is then calcinated in two rotary kilns at 780-1050 °C. After screening, calcinated lime may be used in the Lime Plant, consumed in the Palletizing Plant, Briquet Unit or for industrial water production.

At the direct reduction plant, pellets are charged in Midrex shaft furnaces after misco-grain screening (less than 5mm). Two reducing gases (derived from cracking natural gas or methane, consisting of CO and H2) are injected into the furnace, combine with oxygen from the pellets resulting in CO2 + H2O. Without oxygen, pellets become sponge irons. After screening, sponge irons are transferred to the Steel Plant. Sponge irons with a diameter less than 5 mm go to the briquet unit to produce briquets (diameter above 25 mm). Then, they are transferred to the Steel Plant with the sponge iron.

Steel making and continuous casting plant

The steel making & continuous casting Plant has eight electric arc furnaces receiving sponge iron and other additives. They are melted with about 15% scrap in the furnace, which has a capacity of 180–200 tons. The plant also has four (to be increased to eight in current revamping) ladle furnaces and one (to be doubled) degassing vessel, used to adjust the final chemical mix and purity, as well as adjusting casting temperature. Additionally, there are four continuous slab casting machines, each having two arc casting strands (radius: 10.5 m). They produce the plant's final product, called slabs. These slabs are 10 m long, 20 cm in thickness and 65–188 cm (adjustable) width. Slab production capacity is 4,200,000 t/yr (revamping year 2000), to be increase in steps to 5,400,000 and 7,200,000 MTPY. Slabs are manually cooled and scarfed in the Slab Cooling & Conditioning plant. Scarfing involves removing defects and zones of impurities before further processing.