Open Pit Mining

Open pit mining method is one of the surface mining methods that has a traditional cone-shaped excavation and is usually employed to exploit a near-surface, nonselective and low-grade zones deposits. It often results in high productivity and requires large capital investments, low operating costs, and good safety conditions. The main topics that will be discussed in this chapter will include an introduction into the general features of open pit mining, ore body characteristics and configurations, stripping ratios and stripping overburden methods, mine elements and parameters, open pit operation cycle, pit slope angle, stability of mine slopes, types of highwall failures, mine closure and reclamation, and different variants of surface mining methods including opencast mining, mountainous mining, and artisan mining.

Ecofriendly Hill Mining by Tunneling Method

Mostly, hills are mined by ‘Strip mining’ i.e. removing the hills from top. This conventional approach destroys the landscape and defaces the beauty of the hill. Besides, a large amount of dust generated at source disturbs the villagers and nearby human settlements during the excavation operation or related activities. To eliminate this, and remove the ‘out yard dumping of material’, except at initial stage i.e. during developmental phase, if tunneling methods of civil construction work is applied, ‘the conventional hill mining’ can be turned into an eco-friendly hill mining with very little planning efforts. This chapter highlights the abovementioned aspects of ‘hill mining’ covering overviews about the ‘hill mining by tunneling method’. In this technique, the extraction of mineral deposits is done by driving tunnels at the bottom (or other accessible higher level of the hills) and combining it with cross-cuts and adits, to protect the green cover and the serene hill environment. A case study of limestone mining in hilly Meghalaya region of India forms a part of the description where its feasibility exists.