Unit process

Purpose

Energy source

Temperature in oC

Type of furnace

Electrolysis of molten salt

To produce Al,Mg and Na

Electric energy

700 to 900

Hall-Heroult cell,

Refining

To produce steel

Chemical and electric

1600

LD Converter
Electric furnace

Melting

To produce castings of metals and alloys

Electric and fossil fuel

Above the melting points of respective metal and alloy

Induction furnace, reverberatory furnace and melting furnace

Matte smelting

To produce matte

Chemical and fossil fuel

≈1200

Flash smelter, Reverberatory smelter

Reduction smelting

i) To produce hot metal
ii) To produce lead  and
iii) To produce Zinc  

Chemical and fossil fuel

Chemical and fossil fuel

≈1700 to 1800at the tuyere in all the cases

Iron blast furnace
Lead blast furnace and
Zn blast furnace

Converting

To produce copper from matte

Chemical energy

1100 to 1200

Side blown converter