Ferrous and Non-Ferrous Metals: Production, Properties, and Uses

Ferrous Metals: Definition and Production

Ferrous materials, also known as steel products, are all those with iron as their main component. The primary types include cast iron (or pig iron) and steel.

Pure iron is weak and soft. To improve its properties, iron alloys are created by mixing iron with carbon. The amount of carbon added determines whether cast iron or steel is produced; cast iron has a higher carbon content.

Steel Manufacturing Process

Steel is typically obtained through a foundry process conducted in three main stages:

1. Concentration
2. Reduction
3. Refinement

The Reduction Stage

During the reduction stage, iron ore is introduced into a blast furnace along with coking coal and limestone.

• Coking coal serves as a fuel with high calorific value.
• Limestone acts as a flux, helping to separate impurities from the ore.

Products of the Blast Furnace

The primary products obtained from the blast furnace are:

• Cast iron (or pig iron): This is the result of the initial melting process. It contains a high carbon content and many impurities.
• Slag: The other significant byproduct, consisting of impurities separated from the iron.

Refinement and Steel Shaping

The initial cast iron is too brittle due to its high carbon content and cannot be easily shaped. Therefore, it undergoes a refinement process in special furnaces, which can include cupola furnaces for smelting, converters, or electric arc furnaces for steel production.

Commercial steel is available in various solid forms, such as:

• Plates
• Bars
• Profiles
• Tubes

Both foundries and steel mills consume large amounts of energy to melt and maintain the metal in a molten state. They also produce significant waste, including fumes and slag.

Types of Steel

Steel can be broadly categorized into two main types:

• Carbon Steel
• Alloy Steel

Carbon Steel

Carbon steels are the most common type, primarily containing iron and carbon.

Alloy Steel

Alloy steels contain, in addition to iron and carbon, other metals to form a specific alloy. For example, stainless steels contain chromium and nickel, making them highly resistant to oxidation and corrosion.

Non-Ferrous Metals: Properties and Applications

Beyond iron and steel, several other metals are widely used in various industries. The most commonly used non-ferrous metals include copper, aluminum, zinc, chromium, and titanium.

Copper

Properties of Copper

Copper is known for its excellent properties:

• Good electrical conductor
• Good thermal conductor
• Good corrosion resistance
• Highly ductile and malleable

Compared to ferrous metals, copper is denser, softer, and generally less resistant to mechanical stress.

Applications of Copper

Common applications for copper include:

• Production of electrical cables and other electrical components
• Containers for heating liquids
• Water mains and gas pipes

Brass

Properties of Brass

Brass is an alloy of copper (Cu) and zinc (Zn). While its electrical conductivity is lower than pure copper, it gains significant advantages:

• Increased mechanical strength
• Higher hardness
• Improved elasticity (making it easier to shape)

Brass is generally more affordable than pure copper.

Bronze

Properties of Bronze

Bronze is an alloy of copper (Cu) and tin (Sn). Similar to brass, its electrical conductivity is reduced compared to pure copper, but it offers enhanced properties:

• Increased mechanical strength
• Excellent corrosion resistance
• Higher hardness
• Ease of melting and molding

Bronze is typically more expensive than pure copper.