Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
156770_297BE_barakova_m_ya_zhuravleva_r_i_angli....doc
Скачиваний:
21
Добавлен:
30.10.2018
Размер:
3.64 Mб
Скачать

4. Определите по суффиксу, какой частью речи являются следующие слом. Переведете их:

dig — digger — digging load — unload — loader — loading — unloading

strip — stripper — stripping explode — explosion — explosive

wash — washing — washery depend — dependent — dependence — independence

consume — consuming explore — exploration — exploring — exploratory

friable — friability remove — removal — removable — removing

dump — dumper — dumping produce — production — productive — product —

productivity — producer

5. Прочитайте следующие сочетания слов и переведите их:

strip mines

independent mechanical units

access to the deposit

handling equipment

mine cars

friable ground

overburden removal

an extracted area

low-grade deposits

land reclamation

waste heaps

exploratory workings

earth-moving equipment

car drills

gravel and sludge pumps

removal of waste rock

ore concentration plants

trends towards open-cast operations

searching for minerals

6. Определите значения следующих слов по сходству их корней с корнями соответствующих слов в русском языке:

horizontal slices; type of overburden; the whole production process; the following basic parts; mineral excavation; various mechanical handling equipment; specially equipped permanent stations; in harmony with environment

7. Прочитайте текст а. Назовите основные этапы и перечислите технологические процессы открытой разработки месторождений полезных ископаемых.

ТЕКСТА Open-cast Mining

Minerals at shallow depths are extracted by open-cast mining which is cheaper than underground mining. Open-cast mining consists in removing the overburden, and other strata that lie above mineral or fuel deposits to recover them.

Opencasts or open-pit mines are in fact quarries for getting coal or metalliferous minerals. In the USA opencasts are called strip mines (strip pits).

All the surface excavations, waste heaps and equipment needed for extracting mineral in the open form an independent mining

Unit 9

219

unit. An opencast is a long, wide and comparatively shallow working though it can reach 200 m or even more in depth.

Fig. 9. Open-cast working

In opencasts the excavation is by horizontal slices corresponding to the type of mineral or overburden in slice. In Fig. 9 one can see the benches (or slices). A bench is a thickness of rock or mineral which is separately broken or excavated. Other open workings are called trenches, which are long, narrow, shallow exploratory workings.

The whole production process in opencasts can be divided into the following basic stages: 1) preparing the site to be worked; 2) de-watering it and preventing inflows of water to the site; 3) provid­ing access (entry) to the deposit by the necessary permanent investment; 4) removal of overburden (stripping); 5) mineral excavation.

Stripping the overburden and mineral production include breaking rock or mineral, transporting it and loading it.

Minerals can often be dug directly by earth-moving equip­ment, while to break hard rocks it is necessary to use explosives.

Modern methods of working opencasts involve the use of mechanical plants or hydraulicking. The basic units of a mechanical plant are excavators, car drills or other mounted drills, and various mechanical handling equipment whereas the basic units of hydraulicking are monitors, pumps such as sludge pumps or gravel pumps. Hydraulicking can be used in soft or friable ground.

Transport operations involve the removal of waste rock or mineral, the latter being transported to coal washeries, ore concentration plants, to power stations, or to a railway station. Waste rock is removed to a spoil heap or dump (tip) either outside the deposit or in an extracted area, these being called external or internal dumps, respectively.

220 Unit

The transport used in opencasts are rail cars, large lorries, and conveyers. Sometimes the overburden is stripped and dumped by excavators without other transport, in overcasting or sidecasting.

Mineral is usually unloaded at specially equipped permanent stations. Waste rock is dumped at various points which are moved as the work develops.

Summing up, mention should be made of the fact that last decades have seen a marked trend towards open-cast operations. Large near-surface (though usually low-grade) deposits offer the possibility of achieving greater outputs. There can be little doubt that the cost per ton of ore mined by underground methods is generally higher than that for open-cast mining.

At the same time it is necessary to say that although efforts are made to develop mine sites in harmony with the environment, extraction methods produce some disturbances on the Earth's surface which reduce its economic value. In recent years Russia and other countries have developed national programmes for environmental protection. The aim of such programmes applicable to the mining industry is to control and protect natural resources and regulate reclamation and landscape restoration.

УПРАЖНЕНИЯ

Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]