Reclamation

Reclamation

Reclamation is the act of restoring the quarried area to the pre-quarry state and renders it useful for different purposes. In USA and other foreign countries, the mining laws require that the quarried area is restored to the pre-quarry state. As already stated, such law does not exist in our country and the abandoned quarries present unsightly appearances of hillocks of overburden and vast ponds of stagnant water. Only in Neyveli Lignite Complex the quarried area has been-reclaimed and turned into pleasant parks, mini-forests, zoos and recreational centres, In fact, with a little foresight and planning, the quarried area can be rendered more useful and valuable than in the original pre-quarry state. Thus waste marshland, after the underlying mineral is excavated, can be turned into a profitable agricultural land.

When starting the quarrying activity in an area, if reclamation is one of the final objects, the top soil is removed by rippers and scrapers and collected at a suitable place where it will not be carried away by wind and will not prove a nuisance to nearby localities and dwellings. In suitable cases such soil can be sold away, thus doing away the need to stack it over a long period of the life of the quarry. Small grass is allowed to grow over it so that it is not raised and carried away by the wind.

After the mineral is excavated and the quarried area backfilled, it is compacted by rollers. Tamping or sheepsfoot rollers are the standard tools for compacting fills. They consist of steel drums fitted with projecting "feet" and towed by means of box frames. The portions earmarked for roads and houses are further compacted, but the areas reserved for agriculture, farm land or plantation of trees are covered with 1-1.5 m of soil transported from other places. Such soil is often mixed with appropriate type of manure to suit the agriculture or vegetation planned.

 

Fig. 5.27. Asheepfoot roller for compaction.

Drains are provided all around the reclaimed area. In the areas earmarked for houses, and roads compaction by rollers is carried out for 2 or 3 seasons after the rains with a view to consolidate the back filled debris nearly as compact as in the pre-quarry state.

QUESTIONS

1.  What is the scope and what are the limitations of working a seam by opencast mining ? What is quarriable limit?

2.  What is the common type of equipment used in a mechanised quarry ? State the purpose for which it is used.

3.  Under what conditions will the following equipment be used ?

(a)  A dipper shovel

(b)  A scraper

(c)  A dragline

(d)  A wagon drill

4.  What is the reasonable performance of a 2m³ shovel in (a) an 8-hour shift (b) a week (c) an year.