Exersices:

1. Answer the following question

1.What is prospecting? And what is proving?

2.How did prospectors find mineral deposits prior to the 20^th century?

3.Does gold occur in nature as a heavy malleable yellow metal or as a heavy dark gray one?

4. What metal is capable of attracting a piece of iron?

5. What does prospecting work provide?

6. What are three main stages of prospecting?

7. Is it enough to know only the topographical relief of a locality for exposing this or that mineral?

8. What methods of prospecting do you know?

9. What are the most effective aerial methods of prospecting now?

2. Read the sentences. Find out those which correspond to the text:

1.The search for economically useful mineral deposits is called proving.

2.Last century prospectors looked for visible evidence of mineral deposits.

3. The first ores of iron to be mined were deposits of galena.

4. The science of geology can explain the mode of occurrence of ore deposits.

5. Leveling indicates whether it is advisable to explore the deposits or not.

6. As a rule prospecting includes four stages.

7. The study of general topographical relief and the type of ground makes it possible to expose this or that deposit.

8. Geologists know that certain deposits are only found in a particular type of ground.

3. As is known, veins are found in metamorphic rocks.

3. Retell the text.

40. Recent developments in openpit mining

1.Recent developments in open-pit mining have been largely in free fields-increasing the size of equipment, improving the methods of pit planning and ensuring maximum slopes. The last decade has seen truck capacity rise from 50 to 200 tons and the bucket size of shovels has increased from 6 to 25 yd. The computer has been widely used for pit planning. Research into pit slopestability is being actively persued every where.

2.As with other types of equipment, drills have tended to increase in size and there has been a movement toward large-diameter holes, and wider spacing. Holes with diameter from 9 to 12 in. are now more common, and efforts are being directed toward improving efficiencies in this range. Faster drill penetration is an obvious way to lower costs per foot drilled and this may be obtained by automation to give optimum rotation speeds and pressures. Research into bit metallurgy may be expected to increase bit life.

3.There appears little probability that lasers, electron beams or electrical disintegration will become standard practice in the next decade, but it is possible that a high-pressure water-jet drill may be successfully developed. The electric shovel as a loading unit is now highly developed. More recently large hydraulically-operated face shovels with more efficient front-end-loader buckets have been tried and can be expected to replace the rope-operated shovel. Extremely large stripping shovels and draglines are now in operation in strip mines.

4.Over the last years the strides have been made in the field of haulage. Engine size and power no longer restrict truck size.

5. As the size of other equipment has been increasing, so has the size of scrapers and rippers. However, ripping is still limited to relatively soft rock or material that has been shattered (роздрібнювати) by blasting.

6. Bucket-wheel excavators have been increasing in size and efficiency along with other types of earth-moving equipment. It has become possible to excavate harder materials than was previously possible, but their use is still limited to relatively soft or friable material. Further advances in design can be foreseen, which would enable these machines to mine harder materials.

7. As the depth of the pit increases the amount of waste rock that has to be removed to uncover a ton of ore tends to increase too. That is why in the initial stages of open-pit operation large bowl scrapers have been combined with a conveyer system to remove a large quantity of soft overburden quickly.

8. Nowadays one of the largest problems to be solved is environmental protection, the fight against pollution of the earth's air and sea. Mines and concentration plants are to be obliged to plan their operations and the disposal of their waste products to avoid pollution. Mines and plants will have to take into account to a greater than before the disposal of their products.

Notes

boom {bu:m} (n) – стріла (екскаватора)

bucket (n) - ковш

bucket-wheel excavator - роторний экскаватор

bucket-ladder excavator - багаточерпаковий экскаватор

multi-bucket excavator – багатоковшний экскаватор

single bucket excavator - одночерпаковий экскаватор

shift (n) - зміна

per shift - за зміну

Exercises:

1. Define the main idea of the test.

2. Make the short plan of the text.

3. Answer the following questions:

1.In what fields have recent developments in openpit mining taken place?

2. How can faster drill penetration be obtained?

3. Will lasers become standard practice in the next decade?

4. What shovels can replace the rope-operated shovels in future?

5. What rocks can bucketwheel excavators dig?

6. What is one of the largest problems to be solved nowadays?

4. Prove the statements

1. The size of equipment used in open-pit mining has increased.

2. Drilling technique has greatly improved.

3. New types of equipment are under trial or they are being introduced.

4. Environmental protection is an important problem.

5. Retell the text

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