Industrial Rocks and Minerals: Types, Uses, and Applications
1. Industrial Rocks
1.1 Aggregates
Aggregates are stones or pieces of various sizes used in construction. They are key components of concrete, cement, and mortar. Natural aggregates like gravel are extracted directly from nature (e.g., riverbeds). Artificial aggregates are crushed fragments from quarries.
1.2 Agglomerates
Agglomerates are compact masses of materials like sand and gravel, bound with a cohesive material (e.g., gypsum, lime, cement). They are commonly used in construction.
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Lime is an impure oxide obtained by heating limestone to 1000ยบ.
Cement
Cement, crucial for building, is produced by heating a mixture of limestone, clay, and siliceous sand in a furnace. Adding gypsum to this mixture creates Portland cement.
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Gypsum, also important for building, offers good insulation, acoustics, low humidity, and fire resistance.
1.3 Rocks for Construction
Ornamental rocks (e.g., marble) can be cut and polished. Building blocks (e.g., volcanic rocks, calcareous rocks) are used in construction, especially in luxurious buildings.
Other important rocks include basalt and ophitic rocks, used as construction aggregates. Quarries exploit carbonate rocks (limestone, dolomite, marble) for ornamentation, aggregate crushing, and cement production. Shale, slate, and granite are also quarried.
1.4 Glass
Glass, derived from quartz, is often mixed with other products like alkali oxides, lime, or fluorine. Glass is hard and brittle when cold, but pasty and plastic at high temperatures. It resists most chemicals and is a poor conductor of heat and electricity.
1.5 Ceramic Products (Clay)
Ceramic products include earthenware, porcelain, tiles (used in construction), and refractory products (used in industry due to their high-temperature resistance).
2. Industrial Minerals
2.1 Metallic Minerals
Metallic minerals contain metal and are essential for industry.
- Iron: Constituting 4.7% of the Earth’s crust, iron is extracted from minerals like magnetite, hematite, and limonite. It is fundamental for industrial development.
- Aluminum: Lightweight, sturdy, and abundant (7.5% of the crust), aluminum is extracted from bauxite and used in alloys, notably in the airline industry.
- Copper: Found as chalcopyrite, cuprite, malachite, and azurite, copper (0.01% of the crust) is essential for various applications.
- Tin: Valued for its malleability, tin is extracted from cassiterite.
- Zinc: Zinc improves the characteristics of other metals and protects against atmospheric agents. It is primarily extracted from blends.
- Lead: Harmful to health, lead is used less frequently.
- Mercury: Obtained from cinnabar, mercury is used in thermometers and barometers.
Plants cultivated for human and livestock consumption include cereals (70%), legumes, tubers, fruit trees, and vegetables. Cultivated land covers about 4 million hectares, with forests (40%), meadows and pastures (10%), unproductive land (16%), and farmland (33%).
2.2 Non-metallic Minerals
- Silicon: Present in almost all rocks, silicon (25% of the Earth’s crust) is used in cement, glass, solar panels, and more.
- Sulfur: Abundant in pyrite, sulfur is used in sulfuric acid, fertilizers, and perfumes.
- Sodium: Found in rock salt deposits, sodium is used in the food industry and other applications.
- Calcium: Representing 3.5% of the crust, calcium (found in calcite, dolomite, gypsum, and fluorite) is used in construction, agriculture, and paper and paint manufacturing.
- Potassium: Found in silvite and carnallite, potassium (2.6% of the crust) is used as a fertilizer and in the food industry. It is also essential for crystals, ceramics, and enamels.