(2) Iron Ore. Iron ore is reduced to pig iron in a blast furnace, and the impurities are removed in the form of slag (figure 2 on the following page). Raw materials charged into the furnace include iron ore, coke, and limestone. The pig iron produced is used to manufacture steel or cast iron. To convert iron ore to iron, the iron ore is smelted with coke and limestone in a blast furnace
(figure 3 on page 13) to remove from it the oxygen (the process of reduction) and earth foreign matter. Limestone is used to combine …show more content…
The iron ore, limestone, and coke are charged into the top of the furnace. Rapid combustion, with a blast of preheated air into the smelter, causes a chemical reaction in which the oxygen is removed from the iron. The iron melts, and the molten slag, consisting of limestone flux and ash from coke, together with compounds formed by the reaction of the flux with substances present in the ore, floats on the heavier iron liquid. Each material is then separately drawn off.
(3) Plain Carbon Steel. Plain carbon steel consists of iron and carbon, the latter being the hardening element. Tougher alloy steel contains other elements, such as chromium, nickel, and molybdenum.
Cast iron is nothing more than basic carbon steel with more carbon added together with silicon. The carbon content range for steel is
0.03 to 1.7 percent, and for cast iron 4.5 percent.
(4) Steel. Steel is produced in a variety of melting furnaces: