Steel Manufacturing

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MANUFACTURING PROCESS

Some of the technological options for converting iron ore to steel products is schematically shown below.Hot metal and crude steel process are also inter linked among themselves as represented by arrows.

OTHER STEEL MAKING PROCESSES

THE ELECTRIC ARC FURNACE The electric arc furnace as the name suggests is a furnace in which heat is generated with the aid of electric arc produced by graphite electrodes. The main components of the electric arc furnace are the furnace shell with tapping device and work opening, the removable roof with the electrodes and a tilting device. The furnace shell is circular and with a refractory lining. The work opening and the tapping device are arranged opposite each other for tapping purposes, the complete furnace is tilted to an angle of about 42 degrees. Normally, the furnace is charged with its roof removed. When scrap is added, a charging bucket travels over the furnace, the bottom opens and the scrap is charged into the furnace within a few minutes. During the process, a control system advances the slow burning electrodes. High voltage is transformed into low voltage and high amperage. The most important parameter for the efficiency of an electric arc furnace is the "specific apparent power of the transformer" - in terms of 1 t of charge. Values range from 300 to 750 kVA/t (kilo-volt-ampere per tonne). In some cases, as much as 1,000 kVA/t has been installed.
THE MELTING PROCESS
The electric arc furnace process generally follows the following pattern.
· Charging · Melting · Oxidising · Deoxidising or refining
Besides scrap or sponge iron, the charge also includes the ores, fluxes (lime, flourspar), reducing agents (carbon) and alloying elements in the form of ferroalloys. These can be added through the work opening before or during oxidizing.

Process begins with the ignition of the electric arc. After melting, further scrap can be added. An additiona...