Mining and Mineral Resources Mrs. Rubright Earth Science Week 19

Nonrenewable Mineral Resources Earth crust = Minerals + rock Minerals –inorganic compound that occurs naturally in the earth’s crust Solid Regular internal crystalline structure. Rock – solid combination of 1 or more minerals.

Mineral Resource: Any mineral useful to humans Metallic Minerals: Iron Oxide, Gold Non-metallic mineral: Limestone, sand Fossil Fuel; Coal, Petroleum Ore: A rock that can be profitably mined for a mineral (often a metal) or for minerals (metals) High Grade Ore; has high concentration of the mineral Low Grade Ore: smaller concentration Gangue: Minerals other than ore present in a rock

Life Cycle of a Metal Resource Surface mining Metal ore Separation of ore from gangue Smelting Discarding of product Recycling Melting metal Conversion to product Figure 12.7: Life cycle of a metal resource. Each step in this process uses large amounts of energy and produces some pollution and waste. Smelting – heating to release metals but creating air polluting by-products Chemical removal processes such as using cyanide to remove gold can create Toxic holding ponds

Surface Mines Open pit mines Strip mines Where large 3D ore body lies close to the surface Leaves a large exposed hole on the surface Exposed rocks prone to weathering and polluting Strip mines Mostly for coal where minerals occur in layers paralleling the surface Waste rocks dumped back as spoil banks Newer regulations require reclamation involving grading, restoring, and replanting Can cause changes in topography and drainage

Extracting Mineral Deposits Surface mining - shallow deposits in US extracts 90% of non-fuel minerals and rocks and 60% of the coal. Overburden – soil and rock overlying deposit. Spoils – discarded overburden Open-pit Mining Area Strip Mining

Mountaintop Removal Figure 15-14

Extracting Mineral Deposits Subsurface mining - deposits that are too deep for surface mining Disturbs less produces less waste but also less effective and dangerous.

Underground Mines Generally less disruptive than surface mines Tunnels closely follow the ore body Some waste rock on the surface Shallow abandoned mines can cause collapse

Guyana Gold Mining Situation Guyana is under heavy international pressure to mine their resources for these reasons: To repay foreign debt Meet international demand for gold River dredging Missile dredge – huge vacuum cleaner sucks up gravel, sand and mud for processing at the surface River dredging can change the entire river channel

Guyana Gold Mining Situation Irresponsible mining in Guyana results in: Damage to river channels making transportation difficult or impossible on rivers Damage to ecosystems in rivers; dredging severely disturbs riverbeds by bringing submerged mud and sand to the surface, organisms living in the mud under water die when exposed to the sun altering the natural food chain Indigenous people (Amerindians) loose land, livelihood, and culture Solution: No good solution Government of Guyana needs to protect rights of indigenous people Government of Guyana needs to enact regulation allow mining while protecting the environment

Land Degradation Desertification is the making of new desert through climate change or destructive land use. Desertification affects over 40% of total world land area. Africa: Two thirds drylands, 73 % is moderately or severely affected Asia: One third is drylands, 71% affected, All Pacific islands states face some sort of land degradation North America proportion of drylands is 74% Five European Union countries are affected Latin America and the Caribbean: one fourth drylands, 75% affected 110 countries have drylands that are potentially at risk. Over 250 million people are directly affected and One billion under threat or at risk Global desertification costs: US$42 Billion;

Land is a finite resource

Main Causes of Desertification/land degradation Human activity :over cultivation, over grazing Deforestation Poor agricultural practices Drought and Climate Change

Holistic Managemt Drought & Water stress Food Security Poverty eradication Preserving the resource base for food security - Land Improving livelihood through pro-poor policies on Improving water availability & productivity/Soil fertility quality through sustainable Sustainable Land & Water Management improvement at the core of all long term strategies land & water management Climate change Biodiversity Land is a win-win context for adaptation, mitigation & Holistic Managemt Biodiversity conservation through improvement of land resilience building ecosystems’ conditions Avoided Avoiding Forced Migrations Deforestation Bio Energies Sust. Land Management & Restoration of degraded Lands as an alternative to Opportunities for Bio energies through biomass Changing the DAM paradigm “Degrade-Abandon-Migrate” production Deforestation

Alternative Energy Sources Types of alternative energy source (non-fossil fuels) from Week 18: Solar power Wind power Hydro power Biomass Geothermal power Tidal power Nuclear power Deforestation

Are Alternative Energy Sources the Answer? Consider one of the oldest sources of alternative energy: Hydro power (water) 2017 Oroville Dam Crisis Earthen embankment dam on the Feather River Hydro electric generators provide electric to California residents Deforestation

2017 Oroville Dam Crisis Deforestation

2017 Oroville Dam Crisis Immediate impact Downstream impact Evacuation of residents due to potential collapse of the spillway concrete lip. Downstream impact Eroding of downstream hillside to form canyon. Large amount of erosion debris clogged river below the dam preventing release of water from hydroelectric plant reducing overall usefulness. High turbidity caused by erosion debris caused damage to the Feather River Fish Hatchery forcing evacuation of fish and eggs. Deforestation

Are Alternative Energy Sources the Answer? Alternative energy sources are important to begin to replace non-renewable sources like fossil fuels Alternative energy sources are not without their own challenges. All impacts and costs associated with alternative energy sources must be considered. Deforestation