Question

Open cast mining and placer mining​

Answer 1

Open-pit mining, also known as open-cast or open cut mining, is a surface mining technique of extracting rock or minerals from the earth by  ...

Answer 2

Answer:

1. Open-pit mining, also known as opencast mining, is a surface mining technique that extracts minerals from an open pit in the ground. ... This surface mining technique is used when mineral or ore deposits are found relatively close to the surface of the earth.
2. Placer mining /ˈplæsər/ is the mining of stream bed (alluvial) deposits for minerals. This may be done by open-pit (also called open-cast mining) or by various surface excavating equipment or tunneling. equipment.