Mine rehabilitation

Modern mine rehabilitation aims to minimize and mitigate the environmental effects of modern mining, which may in the case of open pit mining involve movement of significant volumes of rock. Rehabilitation management is an ongoing process, often resulting in open pit mines being backfilled.

After mining finishes, the mine area must undergo rehabilitation.

Waste dumps are contoured to flatten them out, to further stabilize them against erosion.

If the ore contains sulfides it is usually covered with a layer of clay to prevent access of rain and oxygen from the air, which can oxidize the sulfides to produce sulfuric acid.

Landfills are covered with topsoil, and vegetation is planted to help consolidate the material.

Dumps are usually fenced off to prevent livestock denuding them of vegetation.

The open pit is then surrounded with a fence, to prevent access, and it generally eventually fills up with groundwater.

Tailings dams are left to evaporate, then covered with waste rock, clay if need be, and soil, which is planted to stabilize it.

For underground mines, rehabilitation is not always a significant problem or cost. This is because of the higher grade of the ore and lower volumes of waste rock and tailings. In some situations, stopes are backfilled with concrete slurry using waste, so that minimal waste is left at surface.

The removal of plant and infrastructure is not always part of a rehabilitation programme, as many old mine plants have cultural heritage and cultural value. Often in gold mines, rehabilitation is performed by scavenger operations which treat the soil within the plant area for spilled gold using modified placer mining gravity collection plants.

Вариант № 3

I.Перепишите предложения, определите в каждом из них видовременную форму и залог глагола- сказуемого, переведите предложения на русский язык.

1. These students will be sent to Moscow to take part in the conference.

2. A new foreign film is being watched at the cinema now.

3. The farmers will have planted the crops by the end of the month.

4. The last student was being examined at 3 o'clock yesterday.

5. Engineers are trained at this university.

II. Перепишите предложения и переведите их на русский язык, найдите и подчеркните инфинитив и причастие, определите функцию инфинитива и причастия в предложении.

1. To use new machines on the farms is very important.

2. They passed groups of farmers packing ripe apricots.

3. He had the happy look of a man just returned home after a long absence.

4. To increase the yields farmers use fertilizers.

5. The book to be read is on the shelf.

6. Taking a book from the shelf, he sat down under the floor-lamp to read it.

7. Packing was the first thing to be done.

8. To irrigate this area was difficult.

III. Перепишите предложения, найдите и подчеркните объективный и субъективный инфинитивные обороты, переведите на русский язык.

1. The Polish dancers were announced to be arriving next week.

2. The discussion seemed to be coming to an end.

3. We didn't expect him to return so soon.