Gypsum mine in Khothakpa, Eastern Bhutan is a part of the Himalayan ranges. This mine is hilly terrain and therefore proposed to be worked out by opencast system of mining. In view of non-availability of manpower required for manual operation and restricted area available for the required level of production the method of operation is proposed to be worked by semi-mechanized method.
The mining operation consists of the following sequence:
- Preparing of approach roads by bulldozer;
- Development of mining benches;
- Drilling by blast-hole drill and blasting;
- Excavation by power shovel, Excavators & loading into dumpers;
- Transportation of gypsum & waste by dumpers to the stockpile & waste disposal yard respectively;
- Breaking of gypsum manually over stockpile.
The mine benches are developed at 10 metre interval. The mining is done from the top bench-downwards. With of the benches is maintained not less than the height of the benches.