MINERALS MINING Lesson 3 General Mining

MINERALS & MINING Lesson 3

General Mining Law (1872) • 1872 – do you think it was good or bad? ? • Encouraged settlement of western states • Anyone can stake a mining claim on federal lands, buy for $2. 50 - $5 per acre, extract the resources, & keep all profits. • No provisions for environmental protection Image from Wikimedia Commons

…General Mining Law (1872) More than 50 of the 100, 000 to 500, 000 abandoned mines in the US are Superfund sites! Cleanup of all Superfund mining sites will cost an estimated $12. 5 -$17. 5 billion.

Minerals • Elements or compounds of elements that occur naturally in Earth’s crust. • • Ex: steel (mixture), aluminum, copper, concrete (mixture), sulfur, salt, quartz, gold, … you get it. Changed the course of history… • • • Britain = explored for tin. Bronze Age = ruled by the alloy of copper & tin. New World = explored for gold & silver. California = gold rush (1840 s) Rain forests destruction = gold

…Minerals • Mineral Groups: • • Sulfides (S + another element) Oxides (O + metals) Halides (F, Cl, Br, I) Silicates (Si + O) Carbonates (C + O) Native Elements (any pure element) Can be: Metallic • Nonmetallic • NATURALLY OCCURRING INORGANIC SPECIFIC CHEM. COMP. SOLID DEF. CRYSTAL STRUCTURE • Rocks = combo of minerals + other stuff • Ore = rock that contains a large enough concentration of a mineral that makes it profitable to mine for. High-grade ore: large amounts of minerals • Low-grade ore: low amounts of minerals. •

Distribution & Formation • Widely distributed worldwide (see next slide) • Some countries have a lot, some have a little. ======================== 1. Magmatic Concentration • • 2. Hydrothermal Processes • • 3. Hot groundwater dissolves minerals & react with S, making sulfides Sulfides aren’t soluble, so they settle out. Sedimentation • 4. Magma cools & separates into layers Heavy (Fe, Mg) on bottom, Light (Si. O 2) on top Water transports weathered particles and deposits them as sediment Evaporation • Salts & minerals are left behind when water evaporates.

How is mining done? STEP 1: DISCOVER THEM! STEP 2: EXTRACT THEM! STEP 3: PROCESS & REFINE THEM! STEP 4: MAKE THEM INTO A PRODUCT!

Step 1: DISCOVERY Aerial or Satellite photography Measure Earth’s magnetic field & gravity Geological knowledge of how minerals form Drill for samples & analyze composition Sea floor? ? Detailed 3 D maps!

Step 2: EXTRACTION • 2 ways: Surface & Subsurface Mining! • Surface Mining (less $$, less danger) • Overburden must be removed • 4 Kinds: Open-pit mining = dig a big hole to make a quarry. • Strip Mining = dig parallel trenches and create a spoil bank (dump new trench’s overburden in old trench) • Mountaintop Removal = BAD!!! • Dredging = chain buckets & draglines scrape underwater minerals • • Subsurface Mining (more $$, more danger)

Step 3: PROCESSING • Smelting • Melting ore at high temperatures to help separate impurities from the molten metal. • Uses a Blast Furnace • Ore, coke, and limestone react with heat to create: • Purified molten iron (denser) • • Impurities (“Slag”) (less dense) • • Iron Ore + Coke = molten iron + carbon dioxide Limestone + Impurities = slag Exhaust gases are dangerous!

Step 4: CREATE PRODUCT … that means… Create a Product!!

Increasing our Mineral Supplies • Locating & Mining New Deposits • Minerals in Antarctica • Minerals from the Ocean • Advanced Mining Techniques

Increasing our Supplies… Locating and Mining New Deposits • Sometimes we know there are resources out there… but they’re inaccessible. • Malaria in Indonesia, Ice in Antarctica, High sedimentation in Amazon Basin • Create new technologies • Dig 10 km below surface, go through ice sheets, etc. • Possible to find new resources? ? USGS: sure!

Increasing our Supplies… Minerals in Antarctica • To date, no substantial mineral deposits have been found in Antarctica. • • But we might find some! FYI – nobody owns Antarctica… so the rules can get sticky when people want to exploit resources. • ANTARCTIC TREATY – 1961 • Limits activity in Antarctica to peaceful uses such as scientific studies. • Environmental Protection Protocol to the Antarctic Treaty (Madrid Protocol) – 1990 • Moratorium on mineral exploration and development for >50 yrs • People are already ruining Antarctica’s fragile ecosystem… science, tourism, noise, pollution…

Increasing our Supplies… Advanced Mining Technologies • Use more low-grade mineral deposits. • $$$$$$$$ • Causes greater land disruption • Produces far more pollution than high-grade ores • In arid regions, lots of water needs to be pumped in to help with the mining process. • Biomining • Microorganisms can extract minerals from low-grade ores • Copper mining uses it. • They help!! 90% recovery of gold with them • 75% recovery without them. •

Expanding our Supplies by Substitution and Conservation • Finding Mineral Substitutes • Use inexpensive, abundant materials instead! • Old=Tin. New=plastic, glass, aluminum. • Old=Copper wires. New=fiber optics (glass). • Mineral Conservation – important!! (they’re nonrenewable!) • Reuse & Recycle • Changing our Mineral Requirements Become a low-waste society! • Sustainable manufacturing (minimize waste in industry) • • Dematerialization • Decrease weight of products.

RELEVANT LEGISLATION • General Mining Law (1872) • Allowed people to “stake claims” & make profit • Surface Mining Control and Reclamation Act (1977) • Required reclamation of previously mined areas • Only from coal mining!! • Antarctic Treaty (1961) • Limits activity in Antarctica to peaceful uses such as scientific studies • Convention on the Regulation of Antarctic Mineral Resource Activities (1980 s) • Never ratified – would have permitted exploitation of Ant. minerals • Environmental Protection Protocol to the Antarctic Treaty (Madrid Protocol) (1990) • Moratorium on mineral exploration & development for >50 years • Designated Antarctica & its marine ecosystem as a “natural reserve dedicated to peace and society”