Non-energy resources

Non-Energy Resources

  • Historical Context of Mineral Resource Quest

    • Rich human history involving the quest for mineral resources.

    • Significant events:

    • Native American copper trade.

    • Spanish conquistadors.

    • California Gold Rush.

    • Klondike Gold Rush.

Mineral Resources

  • Categories of Mineral Resources

    • Metallic (Metals):

    • Gold

    • Silver

    • Copper

    • Lead

    • Zinc

    • Iron

    • Aluminum

    • Nonmetallic (Building Material):

    • Sand and gravel

    • Gypsum

    • Halite

    • Dimension stone

What Is a Metal?

  • Characteristics of Metals:

    • Opaque, shiny, smooth, conductive solids.

    • Properties derived from metallic chemical bonds.

    • Delocalized Electrons:

    • Move from atom to atom easily, resulting in electron fluidity that renders metals electrically conductive.

    • Example: Pins on a computer processor are coated with a thin layer of gold.

    • Metals vary in behavior and properties due to bond type and structure:

    • Some metals are extremely hard (e.g., titanium).

    • Some metals are soft (e.g., copper, gold).

    • Additional properties:

    • Ductile: Able to be drawn into thin wires.

    • Malleable: Able to be hammered into thin sheets.

The Discovery of Metals

  • Native Metals:

    • Occur naturally in pure form:

    • Gold

    • Silver

    • Copper

    • Iron

    • Historical usage for thousands of years:

    • Tools easily shaped by cold working.

    • Money due to their rarity and durability.

The Discovery of Metals (Continued)

  • Minerals Containing Metals:

    • Utilize mineral ores that contain metal ions bonded to nonmetallic elements.

    • Metal-bearing minerals seldom resemble the pure metal.

    • Example: Malachite, a copper ore mineral, transforms into copper metal.

What Is an Ore?

  • Definition of Ore:

    • Rock that has economic importance and needs to be processed.

    • Contains metal-rich minerals that are concentrated enough to be economically viable for mining.

    • Metals must be readily extracted from the mineral.

    • Characteristics of Ore:

    • Many ores are sulfides or oxides and are often colorful minerals.

Ore Distribution and Grade

  • Geological Distribution of Ores:

    • Ores are not uniformly distributed through Earth’s crust.

    • Geological processes concentrate metals into deposits:

    • Concentration must be high enough to yield a profit.

    • The Ore Grade:

    • Amount of useful metal present in the ore.

    • Different ores are found in diverse geological settings.

How Do Ore Deposits Form?

  • Geological Processes Leading to Ore Formation:

    • Magmatic activity

    • Hydrothermal alteration

    • Groundwater transport (Mississippi Valley-Type - MVT)

    • Secondary enrichment

    • Residual weathering

    • Sedimentary processes

    • Hydraulic sorting

Detailed Processes of Ore Formation

  • Magmatic Deposits:

    • Form from cooling plutonic intrusions where sulfide minerals crystallize early and sink in magma.

    • Result in massive sulfide ores at the bottom of chambers.

    • Example sulfide minerals include:

    • Pyrite

    • Chalcopyrite

    • Galena

  • Hydrothermal Deposits:

    • Formed from hot, chemically active water that leaches metal ions out of nearby rock and precipitates in lower pressure and temperature locations.

    • Can occur disseminated through the intrusion or concentrated in veins.

  • Location:

    • Frequently found near mid-ocean ridges, leading to black smokers where seawater is heated and metals are leached and crystallized away.

  • Mississippi Valley-Type (MVT) Ores:

    • Found in orogenic belts where hot water leaches minerals in deep basins and deposits them where the brines surface and cool.

    • Notable for lead-zinc (Pb-Zn) deposits.

  • Secondary-Enrichment Deposits:

    • Formed when groundwater leaches and oxidizes primary sulfide ores, leading to often visually appealing secondary deposits like:

    • Malachite

    • Azurite

    • Turquoise

  • Sedimentary Deposits:

    • Choose specific conditions to form, often resulting in banded iron formations (BIFs).

    • Composed of layered gray iron oxides and red chert (jasper).

    • Historical formation linked to the buildup of O2 in the atmosphere, dating back 2.5 to 1.8 billion years.

    • Includes manganese (MnO2–rich) nodules that grow slowly on the sea-floor and are rich in trace elements.

  • Residual Mineral Deposits:

    • Formed in rainy tropical settings through extreme chemical weathering.

    • Intense weathering strips away most soil contents, enriching the residual soil in Fe and Al oxides, notably leading to bauxite, which is the primary ore of aluminum.

  • Hydraulic Sorting:

    • Placer deposits formed through flowing water:

    • In high-velocity water, low-density minerals are suspended and washed away, while high-density grains settle down.

    • Known for being important to the extraction of gold, tin, and iron, with the best examples preserved in fossil stream sediments, allowing ore sources to be traced upstream.

Where Are Ore Deposits Found?

  • Tectonic Controls on Ore Deposits:

    • Igneous and hydrothermal activity occurs primarily at plate boundaries, rifts, and hot spots.

    • Tectonic effects are significantly influenced by the hydrologic cycle.

The Discovery of Metals and Development of Alloys

  • Principal Metals Today:

    • Three main metals: copper, iron, aluminum.

    • Copper was the first metal used around 4000 B.C.E., primarily due to the ease of smelting Cu sulfides, albeit it was too soft for effective tools or weapons.

    • The Sumerians invented bronze (~2800 B.C.E.) by alloying copper with tin, resulting in a stronger material than either metal alone.

    • Alloys:

    • Blending metals creates alloys which exhibit properties distinct from those of pure metals (e.g., bronze as an alloy of copper and tin, brass as copper alloyed with zinc).

  • Iron as a Preferred Metal:

    • Iron is stronger, harder, and more abundant than both copper and bronze.

    • However, it poses more difficulties in smelting because it requires much higher temperatures and a chemical reaction with carbon monoxide derived from burning charcoal.

    • Steel:

    • Resulting from smelting iron with carbon, producing a versatile and stronger material.

Smelting and Its Discoveries

  • Smelting Process:

    • Defined as the extraction of metals from ore minerals.

    • Different minerals necessitate unique smelting techniques, temperatures, and lead to different types of nonmetallic waste called slag.

Metals in Modern Society

  • There are approximately 63 metals utilized in the modern world, categorized as follows:

    • Precious Metals:

    • Gold (Au), Silver (Ag), Platinum (Pt)

    • Base Metals:

    • Copper (Cu), Lead (Pb), Zinc (Zn), Tin (Sn)

    • Historical context: Before 1700, only nine metals were actively used: Au, Cu, Ag, Hg, Pb, Sn, Sb, Fe, and As.

Ore Exploration and Production

  • Geologists actively map various terrains—jungles, deserts, tundras—to locate ore deposits.

  • Once potential deposits are identified, assessment includes:

    • Geophysical response

    • Core drilling

    • Geochemical analyses

  • If a deposit proves economically viable, it is developed for mining while considering environmental concerns, ensuring extraction can still yield profit.

Types of Mining Operations

  • Open-Pit Mining:

    • Suitable for shallow ore bodies and less dangerous than tunnel mining.

    • Typically targets ore within 100 meters of the land surface, resulting in large excavations.

    • Process includes breaking rock with explosives, followed by removal for processing.

    • The concentrated ore metal undergoes treatment or smelting, while waste rock is stored in extensive tailings piles.

  • Underground Mining:

    • Ore is sourced via tunnels or vertical shafts.

    • The ore is loosened through blasting, then transported to the surface.

    • Underground operations are more expensive and present inherent dangers including tunnel collapses and exposure to poisonous or explosive gases.

Nonmetallic Mineral Resources

  • Society extensively utilizes several materials that do not contain metals, referred to as industrial minerals:

    • Dimension stone

    • Crushed stone/concrete

    • Other materials

  • Dimension Stone:

    • Rock slabs utilized as building materials, valued for visual appeal and durability.

    • Requires specific properties of rock and careful cutting employing specialized quarrying tools and skilled personnel.

    • Cut and polished slabs are highly prized in construction and design.

  • Crushed Stone (Aggregate):

    • Integral for multiple purposes, primarily forming the foundation for roads and railways.

    • Acts as raw material in the production of cement, concrete, and asphalt; widely employed in modern infrastructures.

  • Common Household Nonmetallic Minerals:

    • Calcite: Base material for cement and concrete.

    • Clay: Utilized in making bricks, pottery, porcelain, and various ceramics.

    • Gypsum: Found in wallboard and plaster.

    • Quartz: Commonly used to manufacture window glass.

    • Rare Earth Elements (REEs): Critical in high-tech applications.

Resource Longevity and Consumption

  • World Demand for Mineral Resources:

    • Enormous global demand with industrialized countries consuming vast quantities.

    • The United States uses approximately 4 billion tons of geological materials yearly, requiring movement of 18 billion tons of material, a figure roughly 95 times the annual sediment load moved by the Mississippi River.

  • Nonrenewable Nature of Mineral Resources:

    • Defined as resources that do not replenish within human lifetimes, formed through geologic processes too slow to produce new deposits, resulting in their irreversible loss once mined.

  • Estimation of Reserves:

    • Mineral resource reserves have been calculated to estimate their expected lifetime based on consumption rates and reserve quantities.

    • Awareness exists regarding the depletion of some resources, with technologies potentially extending their lifetimes.

  • Table of Metal Resources:

    • U.S. and World Resources summarized as follows:

    • Iron: World 120, U.S. 40

    • Aluminum: World 330, U.S. 2

    • Copper: World 65, U.S. 40

    • Lead: World 20, U.S. 40

    • Zinc: World 30, U.S. 25

    • Gold: World 30, U.S. 20

    • Platinum: World 45, U.S. 1

    • Nickel: World 75, U.S. <1

    • Cobalt: World 50, U.S. <1

    • Manganese: World 70, U.S. 0

  • Future Needs for Scarce Minerals:

    • Continued usage will necessitate:

    • Discovery of new mineral sources

    • Price increases for hard-to-obtain reserves to become profitable

    • Improved efficiency and conservation

    • Substitution of materials

    • Recycling initiatives

    • Adjusting consumption behaviors or voluntary deprivation.

Global Distribution and Trade of Minerals

  • Uneven Distribution of Mineral Resources:

    • Largely dependent on the geologic history of specific regions.

    • Trade is essential to bridge resource imbalances.

    • Historical context shows many conflicts and wars arise from imbalances in mineral resource distribution.

    • Strategic Minerals:

    • Sensitive topic regarding metals necessary for national security and defense, which includes:

      • Manganese

      • Platinum

      • Chromium

      • Cobalt

    • Rare earth elements have gained importance in the recent past.

Environmental Impact of Mining

  • Footprint of Mineral Extraction and Processing:

    • Open-pit mines create significant disturbances to landscapes.

    • Mining operations generate considerable volumes of waste tailings, which are often acidic and contain toxic metals.

    • Unvegetated tailing sites can produce dust and contribute to environmental runoff.

  • Acid Mine Drainage (AMD):

    • Sulfides react with O2 to form sulfuric acid (H2SO4).

    • This acid reacts with water to produce acid mine drainage, typically exhibiting a pH < 5.7.

    • The resulting acidity mobilizes iron and various heavy metals that can coat ecosystems and stream environments with rust, posing lethal risks to aquatic biota.

  • Toxic Chemicals from Ore Processing:

    • Release hazardous chemicals during processing which can be dispersed through air and precipitation events to surrounding areas.

    • Recent advancements include improving cooperative practices between producers and consumers, alongside regulatory frameworks governing mining operations to mitigate environmental harm.