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Objectives of the lecture

• Understand basic definitions and classifications of minerals and rocks.
• Explore geological processes that produce mineral resources.
• Learn about the distribution of mineral resources in Earth's crust.
• Study the properties and applications of minerals in construction, like limestone, marble, clay, gypsum, and sand.
• Understand extraction and processing methods for mineral resources, along with their environmental impact.
• Explore sustainability and resource management in the context of mineral resources.

Basic Definitions

• A mineral is a naturally occurring solid with a defined chemical composition and crystalline structure.
• Minerals are mostly inorganic and formed from geological processes.
• Minerals can be pure elements or compounds, not mixtures (examples include NaCl and CaCO3).
• Mineraloids are natural mineral-like substances that lack a constant chemical composition or crystal structure (obsidian, opal, and pearl).
• A rock consists of one or more minerals or mineraloids (examples include limestone, which contains calcite (CaCO3), quartz (SiO2), and clays).

Mineral Classification

• Metallic minerals are ferrous (contain iron) or non-ferrous (no iron).
• Ferrous minerals have magnetic properties and are essential for the metallurgical industry.
• Non-ferrous minerals are more expensive but offer desirable properties, like lightweight aluminum or conductive copper.
• Non-metallic minerals include limestone, gypsum, mica, sand, gravel, clay, and marble.
• Non-metallic minerals are used in cement, ceramics, glass, and lime production.

The Rock Cycle

• A dynamic process that recycles Earth's materials, transforming them from molten magma below the surface to solid rock formations and sediments.
• Three categories of rocks are igneous, sedimentary, and metamorphic.

Igneous rocks

• Formed from solidified magma or lava (granite, basalt).
• Classified by origin and composition.
• Origin can be intrusive (slow-cooling, coarse crystals) or extrusive (fast-cooling, small crystals).

Sedimentary rocks

• Created from the accumulation and lithification of sediment (limestone, sandstone) or precipitation from solution (evaporites, gypsum).
• Formed through deposition and compression including erosion, transportation, deposition, compaction and cementation of minerals, rock fragments, and organic matter.

Metamorphic rocks

• Derived from pre-existing rocks called protolith or parent rock (sedimentary, igneous, or metamorphic).
• Transformed by pressure and heat.
• Metamorphic changes can result from increased temperature, pressure, or the involvement of chemically reactive fluids.

Earth's Crust Composition

• Nine elements make up over 99.5% of the crust (oxygen, silicon, aluminum).
• Minor and trace elements account for less than 0.5% of the crust, and need enrichment to form exploitable deposits.
• Mineral deposits often combine with oxygen, sulfur, or carbon and require specific natural processes for sufficient enrichment that spans geological time scales.
• The thin outer shell of the Earth's crust ranges from 10-100 km thick and contains the most exploitable mineral resources.
• Earth’s crust is made up of 46% oxygen, 28% silicon, and contains only 0.4% of Earth's mass.

Increasing Global Demand

• Is tied to population growth alongside economic development.
• New technologies and applications are also driving demand
• Mine output of major metals has expanded dramatically since the start of the 20th century.
• Present technologies use practically the whole periodic table of elements.
• The depletion of readily accessible resources presents challenges that include the need for deeper mining and processing with an increased environmental and potential health impact, as well as higher extraction and processing expenses.

Properties of Minerals

• Physical properties to consider include strength (compressive, tensile, and shear), durability (resistance to weather and wear), density, hardness, thermal properties, and porosity/permeability.
• Chemical properties to consider include: chemical stability, resistance to decomposition or alteration over time, corrosion resistance, and fire resistance.

Specific Applications

• Structural materials (Lect 3, 4, 5) such as concrete (Lect 2), a composite of cement, aggregates, and water (offers great compressive strength), steel and aggregates.
• Binding materials, and ceramic tiles, non-structural (bricks) (Lect 7)
• Decorative and specialty materials

Concrete

• It is the second most consumed material worldwide
• Concrete is fundamental for housing and infrastructure
• High strength material
• Made of raw materials

Aggregates

• Granular, inert material used in construction.
• Crushed Stone (e.g., limestone, granite), sand and gravel.
• Concrete and mortar production and component in asphalt
• Essential for infrastructure
• 30,000 tons per 1 km of highway
• 90% of paved roads contain aggregates
• 2 tons per cubic meter of concrete
• Limestone: ~50-75% of crushed stone and Sand composition varies (often silica-based)

Steel

• Structural components (beams, columns, girders) to form the skeleton of many buildings
• Reinforcement for concrete to increasing its tensile strength
• Bridges, roofing, stairs and elevators

Bricks

• Made of clays and sand and produced by firing clays, shale, and sand,
• Strength and durability are key features
• Key applications include Load-bearing walls in buildings,Non-load-bearing partition walls and Historical building renovation

Earth-Construction Materials

• Global prevalence nearly 50% of the world's population lives in earth-based dwellings
• Common in Brazil and Australia and in less developed countries
• One of the oldest building materials , which are made into Compressed Earth Blocks (CEBs) for sustainability
• Low impact recyclable and biodegradable

Binding Materials

• Cement is the primary binding agent in concrete
• Various types for different applications such as Portland cement, quick-setting cement
• Lime used in mortars and plasters provides flexibility and breathability
• Gypsum plaster (Lect 6) Gypsum-based material used for interior wall finishes (smooth surface and fire resistance)
• Bitumen (Lect 8)is a binder in asphalt for road construction; used in waterproofing applications

Decorative materials

• Marble and ceramics are used for flooring, cladding
• Granite has high durability and varying colors used for countertops and cladding

Limestone

• Limestone forms when calcium carbonate precipitates out of water
• It can occur biologically or non-biologically with some deposited from marine organisms
• 31-10 kilobars pressure (300-1000 MPa) with temperatures of 450-700°C
• Comprises 15% of earths sedimentary crust.
• Carbonate OOZE in modern marine setting and subsidence on volcanic island

Limestone vs Marble

• Limestone is mainly calcite and has fossils whereas Marble is metamorphosed limestone has varied colors and distinctive veins
• Texture in Limestone is grainy with possible fossils but is Uniform and crystalline without layers in Marble
• Limestone is a third the hardness of marble using the Mohs scale
• Limestone is used in cement but marble is used for sculptures

Lime based mortars

• Calcite will recrystallize as hydraulic binders form such as Ca(OH)2

Clays (Lect 3, 7)

• They are cohesive sedimentary rocks with rocks where size fraction lower than 0.002 mm that formed through weathering of silicates
• Has a plasticity (allows to be shaped and molded when mixed with water)
• They are primarily phyllosilicates mineral and a common material in clay

Usage

• Used in bricks, earth construction materials, and ceramic files

Gypsum

• Is a calcium sulphate dihydrate compound in crystalline mineral (CaSO4•2H2O)
• Is white though impurities can give it more gray, brown, or pink
• Formation is natural and synthetic with density of ~ 2300 kg/m^3 and a hardness of below 2
• Used with drywall and Plaster

Sand

• Sand particles can be up to 4mm or as lil as .063mm
• Can be quartzite or carbonate
• Results from weathering yielding finer grains
• Quartzite sand is has higher hardness but carbonate has a higher density
• Main uses is as a concrete aggregate (50 billion tons/year) or glass production in construction
• Deposits transported into the ocean with thicker layers closer to land

Sand extraction

• The extraction can harm the ecosystem so sand is considered a critical resource

Slate

• Is from microcrystalline metamorphic rock derived from shale
• It's a low grade metamorphic material composed of silicates with potassium in a hydrogen lattice