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Environmental Geochemistry III.
Aleš Bajer
Tento projekt je spolufinancován Evropským sociálním fondem a Státním rozpočtem ČR InoBio – CZ.1.07/2.2.00/28.0018
Environmental Geochemistry
Resources
Mineral Resources and Mining
Fossil and Uranium Fuels
Alternative Energy Resources
Environmental Geochemistry
Mineral Resources and Mining
- 2 categories: metallic and nonmetalic rocks and minerals
- place with enrichment of one or more mineral = MINERAL DEPOSIT
- deposit of metal-bearing minerals that can be mined at a profit = ORE
- Ore forms by magmatic,hydrothermal, sedimentary, weathering and
metamorphic processes
-Mineral resources are mined in two ways:
a) OPEN PIT MINE (surface)
b) TUNNEL MINE (underground)
Environmental Geochemistry
Environmental Geochemistry
HOW ORE FORMS?
- By magmatic processes: crystal settling
- solid minerals are denser than
liquid magma.
- crystals sink to the bottom of
a magma chamber
- in this way heavy metals
(platinum, chromium…) forms
Environmental Geochemistry
HOW ORE FORMS?
- by magmatic processes: pegmatites
- water-rich granitic magma causes solidification of large crystals
- rock with extremely coarse-grained minerals is called pegmatite
- extreme size of particular crystals of feldspar, quartz and mica
(10 x 5 m)
- certain rare elements also concentrate in pegmatites (beryl, lepidolite,
tourmaline,…)
Environmental Geochemistry
HOW ORE FORMS? Hydrothermal ore deposits are results of precipitating from
hot water solution. Fluorite, Galena, Barite
Environmental Geochemistry
HOW ORE FORMS? Submarine hydrothermal ore deposits
Precipitate from circulating seawater
near the mid-oceanic ridge.
Environmental Geochemistry
HOW ORE FORMS?
- by sedimentary processes: sedimentary sorting
-Placer deposits from where water currents slow down and deposit
heavy minerals (gold)
Environmental Geochemistry
MINERAL RESERVES
- may increase in two ways:
a) discovery new mineral deposits
b) by increasing a price or improving a technology of extraction
noneconomic mineral deposits change into profitable ones
Changes in the reserves
of some types of ore
Environmental Geochemistry
MINERAL RESERVES
- 4 nations – the United States, Germany, Japan and the former Soviet
Union consume about 75% of used metals, but their population is only
15% of world population. (China 10% - 16%)
Environmental Geochemistry
MINERAL RESERVES
- predictions of future supplies of selected materials use in industry
Environmental Geochemistry
ENERGY RESOURCES
Energy is the basic condition for our current western life style.
- things like hot water, air condition, car, fresh kiwi in the middle
of winter is matter of course for this life style – all depend on
plentiful cheap energy
What are energy resources?
- Fossil Fuels (coal, petroleum and natural gass)
- Uranium Fuels
- Alternative resources
Fossil and Uranium Fuels influence on environment negatively.
Recently we put the accent on alternative resource searching and
saving energy.
Environmental Geochemistry
ENERGY RESOURCES
Source of energy production Use of energy in particular sectors
Environmental Geochemistry
COAL
- formed from decayed remains of plants in swaps – peat
by increasing temperature and pressure
- there are various types of coal (lignite, brown coal, black coal,
antracite)
Coal mining: a) underground coal-mining
– causes subsidence and colaps surface
b) opencast coal-mining
- causes extensive devastation of land
- changes on landscape surface and water
drainage
Use: electricity production (power station) = 60%
steel factory =30%
steam factory =10%
In the Czech Rep. the coal is used for individual house heating.
Environmental Geochemistry
COAL
negative results:
- pollution (acid rain, carbon dioxide emission, thermal pollution in
water
- electromagnetic radiation is escaping at transmission
Environmental Geochemistry
COAL
Formation of coal
Environmental Geochemistry
COAL
Areas in USA where attractive coal deposits are found
Environmental Geochemistry
PETROLEUM (OIL)
- formed from organic matter in shallow coastal waters during
rising temperature and pressure
- convert the organic matter to liquid petroleum
- Petroleum is dispersed in the rock – oil traps
Driling and pumping causes oil spills and land degradation
Transport (pipeline, tanker): oil spills
Refining process causes:
- air and water pollution
Use: gasoline burning – causes air pollution (CO2, NOX, Pb)
Environmental Geochemistry
PETROLEUM (OIL)
Formation of an oil reservoir
Environmental Geochemistry
PETROLEUM (OIL)
Products of rafinery treat
Oil pollution
Environmental Geochemistry PETROLEUM
Four basic types of oil traps
Environmental Geochemistry PETROLEUM
Global oil reserves and oil consumption
Consumption by country: USA (20 mil), China (7,5 mil), Japan (5 mil),
Russia (2,8 mil), India (2,7 mil), Germany (2,5), CZ (200.000)
EU (15 mil)
Environmental Geochemistry
NATURAL GAS
- similar using like petroleum, but causes less pollution
- less world supplies and higher price
- the leading producer is Russia (problematic supplying)
- CZ 10 years ago – almost every individual house heating was
using natural gas x now incresing price of natural gas
= return to coal (increasing of local pollution)
Environmental Geochemistry
URANIUM AND ATOMIC ENERGY
spontaneous emission of
radiation from an element –
radioactivity
- nuclear power plants
use nuclear fission
- fuel is isotope of uranium
U-235 (not spontaneous)
- natural uranium contains
only 1% U-235
- increasing of U-235 is
necessary for using fuel
- used in the form of small
pellets
Environmental Geochemistry
URANIUM AND ATOMIC ENERGY
Environmental Geochemistry
URANIUM AND ATOMIC ENERGY
Radioactive Wastes
- after mining the material is radioactive
- during enrichment radioactive wastes are produced
- fission process produces radioactive waste
(it is more radioactive than original U-235)
- no satisfactory sollution has been found yet
(no permanent storage exists)
- at present there are short-term (till 50 years) and middle-term
(150-200 years) storing
- nowdays pellets are testing to be reprocessed to recover U-235
- lifetime of nuclear power plant is about 50 years – there is
question what to do with it?
Environmental Geochemistry
URANIUM AND ATOMIC ENERGY
The nuclear fuel
cycle
Temporary storage
Permanent storga
Environmental Geochemistry
URANIUM AND ATOMIC ENERGY
Radioactive accident
-generally people are scared about accident at nuclear power
plants
- there were two big accident in past
1979 – USA, Pensylvania, Three Mile Island nuclear power plant
1986 – former Soviet Union, Chernobyl (Ukraine)
- These accidents influenced on large area
Chernobyl – half of Europe
- The accidents was caused by human failures
- Control – warning systems were off
In my opinion atomic energy is alternative for fossil fuels under
the concrete conditions.
Environmental Geochemistry
ENERGY CONSERVATION (SAVING)
42,5% energy waste could be avoided with conservation
Environmental Geochemistry
ENERGY CONSERVATION
- using technologies with higher efficiency
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
-The first opportunity is consistent energy discipline
in household, industry and transportation
- SOLAR ENERGY
- passive solar heating
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
SOLAR ENERGY
-active solar heating (solar collectors)
trap the solar energy and use it to heat water
there are a few problems:
- it is more expensive
- it works only during the sunlight period
- it wants too much space for to be productivity
for example: generating 100 mil. Watts =
energy for 50.000 people it needs 3 km2 of solar panels
In spite of all of this solar energy has the greatest potential
of all alternative energy resources
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
SOLAR ENERGY
Boom of solar energy in CZ causes higher price of el. Energy
Weakness: solar energy needs to be doubled
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
Hydroelectric Energy
- use the energy of water droping down-ward throught the dam
- produces almost of 20% of the world´s electricity
- hydroenergetic plants do not pollute the water and do not
disturb hydrologic cycle
- dams and hydropower systems radically alter stream ecosystem
- today huge hydroelectric dam project are building in China,
Brasil, India, Nepal and Canada
- all of these project influence on environment
- the biggest producer is China
- in the Czech Rep. the hydroelectric sites are limited.
- potential is much lower than in Austria or Switzerland
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
Geothermal Energy
- energy extracted from the earth´s heat
- there are two forms:
- dry heat (transformation from hot rock into medium)
- wet heat (hot spring water is using)
- typical for place with high geothermal activity (vulcanic activity,
earthquake, hot springs)
- in the Czech Rep. geothermal energy is using only locally
- unlike Slovak Rep. and Hungary where it is more common
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
Geothermal Energy
Schematic view of dry geothermal
energy plant
Steam escapes from hot water
heated by deep hot rock
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
Wind Energy
-the specific form of solar energy – sun´s heat creates wind
- it can be use in places with strong and standy wind
- windmills has been used to pump water since Middle Age
- today „wind farms“ are generating electricity
- they are using especilly in California and Hawaii
- in the Czech Rep. the using of this energy is starting to be
discussed. Places with good wind conditions were selected.
- wind energy is discussed in the view of noice and view pollution.
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
Biomass Energy
-the main resource (wood) of heating in past
- today it is used for local burning stoves
- produces so much smoke and pollution especially in winter
- today there are special plant products for production of bioenergy
- it is prefered as alternative energy resources in EU
- large agriculture sites are using for these plants
Energy from the seas
- tidal energy: are not always economical, there are some projects
but not realy using
- wave energy: there are a few wave generators in Northern
Ireland and England
Environmental Geochemistry
ALTERNATIVE ENERGY RESOURCES
Energy for future?
- nuclear fussion: the energy of stars such as the sun
produces when H combine to form He
- huge amount of energy 1 g = 9400 l of gasoline
- the process is known in the view of theory
- but not prepared for realization in the view of technology now!
Conclusion
However there are still quite enough of fossill fuel reserves
it is important to increase using of alternative energy resources.
Energy saving (decreasing of energy use) unlike wasting can increase
the amount of available energy in the quickest and least expensive way.
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