Importance of Minerals & Mining – Comprehensive Study Notes

Module Overview

• Quarter 1 – Module 4 for Senior High School Earth Science (Grade 11/12)
• Two core lessons
– Lesson 1 : Importance of Minerals to Society
– Lesson 2 : Mining Mineral Ores
• Aligned to MELCs:
• Identify minerals important to society (Code S11ES-Ic-7)
• Describe how ore minerals are found, mined & processed (Code S11ES-Ic-d-8)
• Performance Standard : Learners create a community plan to conserve & protect resources for future generations
• Lesson Objectives (learner must be able to)

  1. Identify importance of minerals to society

  2. Describe ore-formation processes

  3. Explain exploration → mining → processing

  4. Propose ways to mitigate environmental impacts

Key Terminology & Concepts

• Mineral (materials science) : naturally-occurring, inorganic, crystalline solid that forms rocks/soils
• Mineral (health) : dietary chemical element (not focus of module)
• Mineral occurrence : concentration of scientific/technical interest
• Mineral deposit : occurrence large & rich enough for possible extraction
• Ore deposit : proven economic mineral deposit
• Ore : rock/soil that can be mined profitably for valuable element(s)
• Aggregate : crushed stone/sand/gravel used as filler in cement, asphalt etc.
• Plate tectonics controls distribution/enrichment of mineral deposits

Why Society Needs Minerals

• "If it cannot be grown, it must be mined."
• Infographic (USGS) : every child born in the USA requires 3.5\text{ million lb} (1{,}587{,}600\text{ kg}) of minerals, metals & fuels in a lifetime
• Breakfast example
– Glass: quartz-rich sand
– Ceramic plate: clay minerals
– Salt: halite
– Utensils: steel (iron alloy)
– Cell-phone: >40 minerals (Cu, Ag, Au, Pt, etc.)
• Household & infrastructure: cars, appliances, roads, houses, tractors, fertilizer, transmission lines, jewelry rely on mined materials

Common Minerals & Their Uses (selected from Table 1)

• Copper : electrical conductor, motors, plumbing, alloys
• Gold : electronics, face shields, architectural glass, medical/dental, jewelry
• Zinc : galvanizing steel, ZnO sun-block, medicines
• Nickel : stainless steel manufacture
• Silver : conductors, photography, medicine
• Aluminum : wiring, aircraft, packaging, utensils
• Iron : steel, magnets, pigments, biomedical
• Borax : fiberglass, ceramics, detergents, fertilizers
• Titanium : white pigment, light-strong alloys
• Talc : paper, paint, plastics, cosmetics
• Clay : cement & concrete
• Coal : steel smelting, electricity, slag by-products
• Phosphate : H3PO4 fertilizers, feed additives
• Potash (K-carbonate) : fertilizer, meds, chemicals
• Lithium : Li-ion batteries


• Rare-earths (La, Ce, Nd, Eu, …) : catalysts, magnets, electronics, lighting

Properties That Dictate Use

• Talc : softness & slipperiness → powders
• Halite : solubility & salty taste → seasoning
• Gold : malleable, non-tarnishing, yellow luster → jewelry, thin coatings

Geological Concentration Processes

• Hydrothermal systems
– Vein deposits (Au, Ag, Cu, Pb, Zn)
– Disseminated/porphyry Cu
– Volcanic massive sulfide & seafloor “black smokers”
– Stratabound sulfides in sediments
• Magmatic processes
– Crystal settling ⇒ chromite, magnetite, platinum
– Fractional crystallization ⇒ pegmatites (Li, B, REE, gemstones)
– Kimberlite pipes (>150 km depth) ⇒ diamonds
• Metamorphic alteration/recrystallization ⇒ graphite, marble, asbestos
• Sedimentary chemical precipitation
– Evaporites (halite, gypsum, sylvite, borax)
– Banded iron formations (hematite, magnetite)
• Placer concentration by running water ⇒ Au, Pt, diamond, tin
• Residual weathering/laterites ⇒ bauxite(Al), nickeliferous laterite, secondary enrichment zones

Locating Ores

• Economic criterion : local grade must exceed crustal average & cover extraction costs
• Gold average crustal abundance \approx0.005\;\text{ppm} = 5\,\text{g} / 1000\,\text{t rock} (not economic)
• Exploration focuses on favorable tectonic settings (ridges, arcs, cratons…)

Lesson 1 Class Activities (Brief)

• Venn diagram : rocks vs. minerals
• Infographic interpretation: lifetime mineral demand
• “Parts of a Computer are Mined” unscramble
• “Minerals in My House” audit & 3Rs reflection

Mining – From Prospect to Product

• Mining : withdrawal of valuable, non-renewable Earth materials
• Three generic extraction categories

  1. Sand & gravel (low waste)

  2. Buried ore bodies (high stripping ratio; e.g., 2\% Cu ⇒ 20\,\text{kg Cu} / 1000\,\text{kg ore})

  3. Ore processing (crushing-grinding-separation)

Phase A : Mineral Exploration

• Project design : data review, permitting, socio-environmental scan, budgeting (Stop-Go)
• Field exploration
– Regional reconnaissance
– Detailed mapping, geophysics, geochem, trenching, drilling
– Prospect evaluation: resource modeling, metallurgy, EIA, socio-economic studies
• Pre-production feasibility : independent verification to secure finance
• Resource modeling : 3-D grade, tonnage, geometry → informs mine design & blasting plan

Phase B : Mining Methods

• Underground mining : deep tabular/high-grade ores (>300 m); expensive; shafts, drifts (Fig. 2A)
• Surface mining : cheaper; open-pit, strip, quarry; used for large, low-grade near-surface deposits (Fig. 2B)
• Placer mining : in river channels, beach dunes; sluicing & gravity separation (Fig. 4)

Phase C : Milling / Mineral Processing

• Goal : liberate & concentrate valuable minerals
• Size-reduction : crushing → grinding → pulverizing
• Separation techniques

  1. Heavy-media separation : dense liquid; heavy sulfides sink (ex CuFeS₂ vs. quartz)

  2. Magnetic separation : magnetite, ilmenite, pyrrhotite attracted to magnets

  3. Froth flotation : reagents + air bubbles carry hydrophobic minerals (e.g., Cu, Zn) to surface froth

  4. Cyanide heap leach : \text{NaCN} solution dissolves Au; pregnant solution processed for bullion
    • Tailings : fine-grained waste → dam or backfill; must be managed to prevent acid mine drainage (AMD)

Phase D : Environmental Management

• Potential impacts : erosion, sinkholes, habitat loss, dust/NOₓ/SO₂, acid drainage, metal leachate, siltation, floods
• Regulatory framework (PH)
– RA 7942 : Philippine Mining Act 1995
– DENR oversight
• Mines & Geosciences Bureau (MGB) : resource development & safety
• Environmental Management Bureau (EMB) : standards for pollution control & monitoring
• Mandatory steps :
– Environmental Impact Assessment (EIA) pre-mine
– Environmental Management Plan (EMP) during operation
– Mine Closure Plan & financial surety
– Post-closure monitoring & rehabilitation (topsoil replacement, re-vegetation, sealing adits, neutralizing acidic waters)
• Rehabilitation success example (Fig. 9): mined pit → recreational lake, reforested slopes

Philippine Mineral Endowment

• 5th most mineralized country globally
– 3rd in gold reserves
– 4th in copper
– 5th in nickel
• Major districts
– Baguio & Mankayan (Benguet): Cu–Au
– Surigao–Davao: Au & Ni
– Palawan, Surigao del Norte: Ni laterite
• Other resources : Fe, chromite, cobalt, Pt, limestone, marble, clay, sand & gravel

Natural-Resource Management – The 3Rs

• Reduce : extend product life; avoid single-use items
• Reuse : pass items to others; repurpose (e.g., jars → planters)
• Recycle : collect & re-process metals, glass, plastics
– Example : broken ceramic tiles (clay) reused as garden path mosaics (Fig. 10)
• Goal : conserve non-renewable minerals, cut waste, lower demand for new mining

Representative Exam / Worksheet Points

• Cement uses clay; gold used in jewelry, conductors, medical; potash for agriculture; borax for fiberglass, etc.
• Evaporites form in closed marine basins; placer deposits need moving water; seafloor nodules rich in Mn–Co–Ni
• Exploration drilling evaluates ore type, quality, tonnage
• Quarrying = surface/open-pit mining
• Magnetic separation best for Fe-bearing ores; flotation for sulfides; cyanide leach for Au
• Environmental risks : erosion, pollution, loss of fauna/flora ⇒ all of the above
• Rehabilitation imperative to restore pre-mining condition & reduce erosion
• Apply 3Rs to conserve, preserve, respect environment ⇒ all of the above

Sample Numeric / Chemical Details

• Average crustal Au : 0.005\,\text{ppm}
• Porphyry Cu grade illustration : 2\% Cu → 20\,\text{kg} Cu per 1000\,\text{kg} rock
• Copper, nickel, cobalt in seafloor nodules; Mn crusts on ocean floor
• Evaporation sequence (marine) : \text{CaSO}4·2H2O (gypsum) → \text{CaSO}_4 (anhydrite) → \text{NaCl} (halite) → \text{KCl} (sylvite)

Ethical & Practical Implications

• Mineral extraction enables modern life but poses sustainability & justice questions
• Balancing economic growth, community welfare & ecological integrity is mandated by law and good governance
• Responsible citizenship : informed consumption, advocacy for responsible mining, implementation of 3Rs

Quick-Reference Equations & Symbols

• Gold in crust: \text{Au}{\text{avg}} = 0.005\,\text{ppm} • Copper yield example: \text{Mass}{\text{Cu}} = 0.02 \times \text{Mass}{\text{ore}} • Density contrast exploited in heavy-media separation: \rho{\text{valuable}} > \rho{\text{liquid}} > \rho{\text{gangue}}

Connections to Previous / Future Topics

• Builds on rock cycle, plate tectonics & earth systems previously taught (origin of igneous, sedimentary, metamorphic rocks)
• Foundation for later environmental science topics: pollution control, sustainability, climate-change mitigation

Real-World Relevance & Careers

• Careers : geologist, mining engineer, metallurgist, environmental scientist, regulator, EHS officer, reclamation specialist
• Everyday linkage : gadgets, transportation, energy, medicine all rely on mined minerals; responsible use influences demand