chapter-1 rocks and minerals and their exploitation.

Question 1

How much does Earth weigh?

Answer 1

5.97×10²⁶

Question 2

What’s the density of the Earth?

Answer 2

5.2g cm-³

Question 3

What is peak mineral?

Answer 3

peak mineral is a concept that provides a date after which the extraction of a mineral will reduce they will be only less extraction of a mineral. peak coal for example is the date on which most coal will be extracted after which the coal will decline.

Question 4

Who introduced the concept of peak mineral?

Answer 4

M.k. Hubbert

Question 5

What did MK Hubbert predict?

Answer 5

In 1956, the originator of the peak mineral idea MK Hubbert predicted that the peak oil date for the USA would be 1970. this did not happen and in fact the production of oil in the USA is still increasing today.

Question 6

Ore:

Answer 6

A rock containing enough of an important element that makes it worth mining.

Question 7

Mineral:

Answer 7

A natural occurring an organic substance with a specific chemical composition.

Question 8

Magma:

Answer 8

Magma is found in the outer mantle it is hot liquid rock that is under pressure from the rocks above it.

Question 9

What are igneous rocks?

Answer 9

The word igneous has been derived from a Latin word called ignis which means fire they are known as primary rocks or parent rocks because all rocks are derived from igneous rocks. there are two types of igneous rocks intrusive igneous rocks and extrusive igneous rocks. Intrusive igneous rocks are formed when magma cools and solidifies under the surface of the Earth the process is quite slow and larger crystals are formed. Extrusive igneous rocks are formed when the magma erupts out of a volcano and reaches the surface of the Earth it cools and solidifies the process is quick and no crystals or small crystals are formed.

Question 10

How are crystals found in rocks are formed?

Answer 10

The crystals found in rocks are formed when solution of dissolved minerals cannot absorb more dissolved minerals. some of each mineral type precipitates out of the solution and creates the center of the crystal this provides a surface for more mineral ions to precipitate onto, the crystal becomes larger until the solution disappears.

Question 11

What are some examples of igneous rocks?

Answer 11

Granite, basalt, pumice, and obsidian.

Question 12

What are sedimentary rocks?

Answer 12

Sedimentary rocks are formed by the weathering of existing rocks at the Earth’s surface or the accumulation and fossilation of living materials or the precipitation of dissolved minerals out of solution in water. The weathering releases small particles which form sediments. over the time, layers of sediments build up to form sedimentary rocks. The sediments are deposited layer by layer or in the form of strata and consequently these rocks are also known as stratified rocks. the examples of these rocks are sandstone, shale, and limestone.The particles are transported by streams and rivers and then deposited as sediment. each layer of sediment becomes more compact and harder because of the pressure created by the new deposits above them.

Question 13

What are metamorphic rocks?

Answer 13

The word has been derived from two Greek words ‘meta’ which means change and ‘morphic’ meaning form. metamorphic rocks are formed when the original character of the igneous and sedimentary rocks are exposed to heat of above 150° Celsius and pressure of above 1.5*10 ^ 8 or 1,480 atmospheric pressures. They undergo change and become metamorphic rocks. The changes in structure can be chemical or physical or both. Granite is converted into gneiss, clay and shale are transformed into schist, and sandstone is transformed into quartzite.

Question 14

Describe and explain the characteristics of igneous rocks.

Answer 14

Characteristics of Igneous rock:
– Usually contain crystals solidified from the molten materials
– Dark in colour and high density; rich in mineral like iron and magnesium
– Light in colour and low density mainly composed of silica

Question 15

Describe and explain the characteristics of sedimentary rocks.

Answer 15

Characteristics of Sedimentary rock:
– Deposited in layers and separated by line or cracks
– Combination of fossils of organism
– Made of sand grain (sandstone), and fossils of sea creatures (limestone)
– Made of tiny clay particles (Shale)

Question 16

Describe and explain the characteristics of metamorphic rocks.

Answer 16

Characteristics of metamorphic rock:
– Formed due to high pressure and temperature
– A very resistant rock (quartzite)
– Dark grey or black (slate)
– Layers of different minerals (gneiss)

Question 17

Describe the rock cycle.

Answer 17

Weathering and erosion break off fragments of surface Rock. the fragments of rock or sediments are deposited and built up in layers as the layers build up the lower layers are compacted into sedimentary rock. when the sedimentary rock and igneous rocks are subjected to heat and pressure they change in structure and they become metamorphic rocks. at higher temperatures rocks melt to form magma the magma cools to form igneous rocks.

Question 18

How are sedimentary rocks transformed into metamorphic rocks?

Answer 18

Sedimentary rock may be broken down into sediment once again by weathering and erosion. It may also form another type of rock. If it becomes buried deep enough within the crust to be subjected to increased temperature and pressure, it may change into metamorphic rock.

Question 19

What is prospecting?

Answer 19

Prospecting is the process of searching for minerals by walking on the surface of the Earth.

Question 20

What is the remote sensing method?

Answer 20

Remote sensing is a process in which information about the earth’s surface is collected from above. unmanned drones and planes are flown over the Earth’s surface and the ariel photography is used to click photographs of the Earth’s surface and the photos are then analyzed to check for sign of minerals.

Question 21

How can satellites help in finding for minerals?

Answer 21

Images and other data from satellites can also be used to analyze very large areas. mineral deposits are weathered at the Earth’s surface, they produce mineral oxides which can be detected by their unique radiation pattern, which is recorded by a satellite and download to a computer for analysis. other satellites operate by sending signals to the surface of the Earth and they collect the reflected signals. they work in all weathers through complete cloud cover and at night.

Question 22

How can valuable mineral ores in the rocks below the surface of the Earth be located?

Answer 22

Valuable mineral ores in the rocks below the surface of the Earth can be located using satellite images. computers process the data of a region of interest to check if they are any minerals present in that area. the satellite positioning system records the exact location, and the geologist then visit the location to see if the minerals were identified correctly. once an area has been identified from satellite data, the geologist can check further locations to see if the minerals are present nearby as well. using satellites means large areas can be geologically mapped quickly and at low cost.

Question 23

What is geochemical analysis?

Answer 23

Field surveys on the ground are used to take samples. samples can be taken from stream sediments, soils and rocks then they are taken to the laboratory for geochemical analysis so that the chemicals in samples can be identified. The points for the sample are usually selected by overlying a grid on a map of the survey field. the location of the sample points in the field can be found accurately using the global positioning system GPS.

Question 24

What is geophysics?

Answer 24

A series of vibrations called seismic waves are sent to the Earth’s surface. several sensors are laid on the ground at different distances from the source of vibration. the vibrations create shock waves that travel into the Rock layers and then are reflected back to the sensors on the surface. the shock wave records different patterns depending on what mineral is present inside the Rock layers. explosives can be used instead of vibrations but this is potentially more dangerous.

Question 25

What is evaluation resource?

Answer 25

The aim of the evaluation is to estimate the grade and the tonnage of the mineral of interest present in a deposit. drilling to collect Rock samples must be done to carry out a resource evaluation. for small deposits only a few samples are needed for large deposits more drilling is required following a great pattern on the ground. the aim is to identify the size of the deposit as well as the mixture of mineral ores present.

Question 26

What is surface mining?

Answer 26

They are different types of surface mining the first one is open-pit mining this type of mining is used when a valuable deposit is located near the surface often buried below a thick layer of worthless material. the material above the deposit is called overburden. the overburden has to be removed first to expose the deposit and it stored nearby to be used later for mine restoration. Open pit mindes are carefully dug in sections called benches. the walls of the benches are kept at an angle to reduce the risk of Rock falls. The safe angle of these walls depends on the type of deposit and overburden. Building materials such a sand, gravel, and stone are removed from open pits called quarries.

Question 27

What is strip mining?

Answer 27

Strip mining is used to mine a seam of mineral first of all the overburden which consists of The overlying Rock and soil is removed. strip mining is mainly used to mine coal and lignite near the surface. it uses one of the largest vehicles on Earth such as bucket wheel excavator, these machines can move thousands of tons of material every hour.

Question 28

What is deep mining?

Answer 28

Deep mining involves digging tunnels into the ground to reach mineral deposits that are too deep to be removed by surface mining. sometimes horizontal galleries are dug directly into the cooal seam in the side of a hill or a mountain these are drift tunnels which can be entered by an adit. these tunnels produce waste rock as well as the mineral ore.
A sloping tunnel is dug to reach deeper deposits. mining machinery can be lowered down the sloping tunnel while waste rock and mineral ore has to be hauled up to the surface.

Question 29

What is shaft mining?

Answer 29

The deepest deposits are reached by digging a vertical shaft. horizontal galleries are then dug into the mineral deposits. this type of mining is more expensive and technically challenging than either horizontal or slope tunneling only large deposits of valuable minerals are mined in this way most of the mineral is removed by machines the miner’s job is to make sure all the machinery is working correctly and safely compared with open pit mining any form of shaft mining is more difficult because the supply of fresh air and water renege has to be provided they also dangers of collapsing tunnels as well as the risks of poisonous gases explosions and underground fire.

Question 30

What are the factors that affect the viability of extraction of minerals?

Answer 30

The costs of exploration and extraction, geology, climate, accessibility, the environmental impact, and supply and demand.

Question 31

How does the cost of exploration and extraction affect the viability of extraction of minerals?

Answer 31

It is easy to look for minerals on the surface when there is a clue of presence of ores such as change in color of part of a rock but it is expensive to do exploration under the sea bed or located deep underground. the probable cause of extracting one ton of ore has to be calculated. deposits near the surface can be extracted by open pit mining. they are usually fewer technical difficulties to mining on a large scale using this method which leads to a lower extraction cost per ton. deeper deposits can only be extracted by shaft mining this is more costly to set up and maintain so the cost per turn will be higher than open pit mining only deposits of high value can be mined economically in this way.

Question 32

What is the strike rate?

Answer 32

Strike rate is the frequency with which chances to find a mineral are successful.

Question 33

How does geology affect the viability of extraction of minerals?

Answer 33

The quality of the mineral deposit, the size of the deposit, and the position of the deposit will affect the viability of the extraction of minerals. The depth of the minerals within the soil will impact on the decision whether to surface mine or use a sub-surface method. if the valuable mineral is in strata the size of the strata may impact the ability to develop tunnels similarly the stability of The Rock will affect the choice of method used.

Question 34

How does open pit mining effect the environment?

Answer 34

Visual pollution or loss of scenic beauty or eyesore, dust or fumes or atmosphere/air pollution, increase in traffic or road congestion, waste heaps and land pollution.

Question 35

How does transportation affect the viability of extraction of minerals?

Answer 35

Transporting The ore from a mine to processing plants may be difficult and expensive. this factor alone could prevent a deposit being mined. the cost of building road or rail links to the processing plants or to the nearest suitable port for export is a startup cost that has to be considered. these transport links have to be kept in working order so they will also be maintenance costs. the cost of transporting one ton of ore over 1 km can be calculated. for large tonnage such as iron Ore, rail transport is the only practical and cost effective method of moving the ore.

Question 36

What are the ways of keeping the transport costs low?

Answer 36

The first way is if the ore is going to be exported, large ships called bulk carriers can be used to keep the transport costs slow. Another way of keeping the transport cost slow is to carry out some processing of the ore at the mine. the process used depends on the chemical nature and the grade of the ore. the aim of processing is to concentrate the mineral and separate it from the waste material. the waste material is stored at the mine, this type of processing produces a higher grade of ore so it has a higher value per ton. some ores are high grade when they come out of the ground. for example some iron ores are called direct shipping ores DSO because they have enough iron content that they do not need processing at the mine.

Question 37

When can mining companies start work?

Answer 37

Mining companies can only start work after they have been given a license to extract a deposit. the government of any country will want to earn some money from the mining activity. this means that there will be a tax to be paid to the government for every ton of mineral ore extracted. From the point of view of the mining company it is important that long-term agreement is reached to avoid rapid prices in tax that could make the mining operation unprofitable. from the point of view of the government the tax need to generate enough money to be invested in developments with the benefit of the country.

Question 38

Why is the amount of money that needs to be invested in starting up a mind is considerable?

Answer 38

If the world price falls because of a drop in demand a new mine may not start working at a profit only when the world price rises again can a new mine become profitable. the global recession of 2008 stopped, some known mineral reserves being mined because of reduced World prices. recently the world’s price of iron ore has dropped because supply is greater than demand.

Question 39

What is supply and demand?

Answer 39

The relationship between how much of a commodity is available and how much is needed or wanted by the consumers of the product.

Question 40

What do the mining companies do with the profits from periods high World prices?

Answer 40

The profits from periods of high World prices are used to make up for periods of low profitability as well as to pay for the development of newly discovered deposits.

Question 41

Describe the surface mining methods of extraction of rocks and minerals.

Answer 41

1. Geological survey is done using satellite image to find out the availability of minerals
2. Finding the exact location of minerals, depth and quantity of minerals
3. Clear the vegetation and remove and the top soil
4. Break up and loosen the rock by using explosives like dynamites
5. Use diggers to remove the loose rock
6. Put the rock or minerals into trucks or railway wagon to be carried for extraction and refining.

Question 42

Describe the subsurface mining methods of extraction of rocks and minerals.

Answer 42

1. Geological survey is done using satellite image to find out the availability of minerals
2. Finding the exact location of minerals, depth and quantity of minerals
3. Sinking a vertical shaft down to the rock layer containing minerals
4. Making a horizontal tunnel following the mineral layer
5. Extracting the minerals by digging done by miners and machines
6. Bringing the loose rock from the mine and piling up on the surface
7. Bringing the minerals to the surface to be transported way in truck or trains

Question 43

how does climate affect the viability of extraction of mineral?

Answer 43

It is unfavourable to extract minerals in a very cold and hot place or heavy rain. It is more favourable to explore and extract minerals in the temperate climate. For example, it is difficult to explore and extract minerals in the polar region due to climatic reason.

Question 44

what are the environmental impact that affects the viability of minerals extracted?

Answer 44

In a no sensitive local environmental issues areas are more favourable for minerals extraction than in those places of environmental concerns and protected areas. For example, in a forested or densely populated area may be sensitive to environmental issues.

Question 45

What are the three negative ecological impacts of rock and mineral extraction?

Answer 45

1.any type of mining requires the vegetation to be cleared from an area of land. the plants will lose a place and the Animals dependent on the plants for food and shelter will leave the area.
2. Deep-mining means that shafts have to be dug down to the seams of valuable minerals. at the beginning of deep mining operations only a small area of land is cleared of vegetation. After this type of mine has been working for several years more habitats will be destroyed as the amount of mine waste stored aboveground increases.
3. Any form of large scale surface mining causes the greatest loss of habitat. After the seams of valuable minerals have been removed. The overburden is spread over the mined area to restore the land. the new land surface will slowly become covered in some plant species however this vegetation will have less biodiversity compared with the original vegetation.

Question 46

What is the environmental impact assessment?

Answer 46

Environmental impact assessment is a process by which the probable effects on the environment of a development are assessed and measured. when a company applies for a license to start working, an environmental impact assessment is carried out. the license application is usually approved if the company has a plan to keep the loss of habitat as small as possible and then to restore the land of the mining has finished.

Question 47

What causes noise pollution?

Answer 47

Noise pollution is a problem when large scale surface mining takes place. the overburden is loosened by explosive charges and then removed by large machines the noise can disturb the behavior of many animal species near the Mine and can cause health problems for people.

Question 48

How is the water polluted?

Answer 48

The water may drain through mine waste or come directly from mine shafts. it causes dramatic changes to the populations of living organisms in streams and rivers.

Question 49

How does the water become acidic and kills sea creatures?

Answer 49

Pollution is caused by chemical reactions between water and exposed rocks and mind waste. the water may become acidic and dissolve toxic metal ions the combination of acidic water with a high concentration of toxic metal ions kills many aquatic organisms.

Question 50

What is bioaccumulation?

Answer 50

Some of the metal ions exist only in low concentration in bodies of water however organisms just absorb these ions and retain them in their body reaching concentrations much higher than in the water this is called bioaccumulation.

Question 51

What is biomagnification?

Answer 51

The concentrations increase further in organisms that are higher up in the food chain this process is called biomagnification and can cause the death of top consumers.

Question 52

How does dust pollution affect plant growth?

Answer 52

Dust reduces plant growth: the leaves of plants need to absorb light energy to perform photosynthesis if light cannot penetrate a layer of dust on a leaf surface and the rate of photosynthesis is reduced.

Question 53

What is the impact of dust pollution?

Answer 53

Dust from mining activities may also have toxic effects depending on the chemical components present in the dust. this can also reduce or stop plant growth and the particles can be dangerous to human health. the biggest risk is breathing in dust that then remains in the lungs. long-term exposure can lead to serious lung diseases that can cause death.

Question 54

Why illegal mining without license is bad for people and the environment?

Answer 54

Illegal mining causes the formation of sinkholes, contamination of soil, ground and surface water pollution. it also affects the health of the mine workers-it causes breathing problems.

Question 55

Explain how reduced plant growth can affect an ecosystem?

Answer 55

The plant is the critical base in most ecosystems. through photosynthesis plants harvest the energy of sun and produce food and oxygen and they provide shelter for animals. declining plant growth lowers and ecosystems productivity many animals go extinct and it also lowers the quality of ecosystem services.

Question 56

Describe and explain the socio-economic impacts of rock and mineral extraction.

Answer 56

1. Employments: employment for local people who learn new skills, either directly in mining or in associated service and manufacturing industries. 2. Foreign exchange: if the mineral is exported it boosts the national economy, as well as the local government. Foreign exchange gained from the sale of exports pays for imports, develops infrastructure and improved the quality of life of its citizen.
2. Infrastructures: road or railways have to be constructed to and from the mine. Other infrastructure has to be provided, including water and power supplies. All also benefit the local people as it make it economical to supply them with the services.
3. Higher wages: More wages in the local community support services, such as shops, so the local economy improves.
4. Taxes: More taxes collected from the mining companies by local governments can be used to develop the area providing more hospitals, improving schools, and adding other facilities.

Question 57

How is mine waste stored nowadays?

Answer 57

In a well regulated system, applications must provide a detailed plan to show how mine waste will be stored to prevent collapse. the site of the mine-waste must also prevent the possibility of water pollution. the plan must include details of how the waste will be monitored to detect any movement or water pollution.

Question 58

How do you manage waste from coal mining?

Answer 58

Sometimes mine waste can be reshaped to blend in with the surrounding landforms. the waste is then covered with a layer of soil which is enriched with fertilizers such an area can then be planted with trees this will help other plants and animals to colonise in the area. as the time passes the soil will be improved by the addition of organic matter from plant and animal wastes this method of land restoration is often used to manage the waste from coal mining planting trees creates habitats fairly quickly even though the trees are only able to grow slowly.

Question 59

What is in in situ treatment and ex-situ treatment?

Answer 59

Contaminated waste can be treated where it was left, this is in in-situ treatment by bioremidation. Alternatively waste can be removed from a side to a treatment plant this is ex-situ treatment.

Question 60

What is bioremidation?

Answer 60

Bioremidation is the process in which living things are used to remove toxic chemicals from a natural site. It is the process of removing pollutants from waste using living organisms, many organisms are able to break down toxic chemicals into less hazardous substances this often happens slowly in natural environments. some microorganisms such as bacteria are able to absorb pollutants and process them via metabolic pathways into less harmful substances when bacteria take in pollutants they usually gain either energy or nutrients.

Question 61

How are plants able to bioaccumulate toxic metals?

Answer 61

Some plants are naturally able to bioaccumulate toxic metals and this process can be speeded up with fertilizers. these plants are grown on contaminated waste. the plants absorb the toxic chemicals and later the parts of the plant above ground removed so that the waste left in the ground becomes less toxic. After the treatment, the land is often turned into a nature reserve as, even though the ground surface is less toxic it may still not be possible to use it for farming or to build houses on. several tree and herb species are introduced and as the plant populations grow they create habitats for many animals species. these nature reserves become valuable green spaces for human recreation as well as helping to maintain biodiversity.

Question 62

What is landfill?

Answer 62

If the rock lining the hole is impervious to water and non-toxic then it can be allowed to fill with water to form a reservoir. this water can be used for irrigating farmland or processed to provide clean safe drinking water for humans. sometimes these holes are filled with household waste until they are full. the waste is then covered with soil and planted with trees this is called landfill.

Question 63

What is the full form of SERI?

Answer 63

The society for ecological restoration international.

Question 64

What did SERI propose?

Answer 64

They proposed a number of ecosystem related variables to measure the success of a land restoration program. in summary, a successful scheme will return the site to as close as possible to the native ecosystem that existed before the mining began.

Question 65

What process do scientists believe is the most beneficial of all?

Answer 65

Some scientists believe that allowing a site to undergo a natural process of recolonization and slow change to the environment a process called succession may actually be the most beneficial method.

Question 66

Why is active reclamation important?

Answer 66

Active reclamation is important to reduce the incidence of such events such as landslides and erosion.