Abstract
PT. Bukit Asam – UPO is one of coal underground mining which conduct mine activity in Ombilin I (Sawahluwung), Ombilin II (Waringin-Sugar) and Ombilin III ( Sigalut). At underground mining, ventilation system is really important for human’s breathing need (worker), to netralize toxic gases, reduce ash concentration and control temperature .
Ventilation system in Sawah Luwung underground mining used suction system with 32,76 m3/second air out quantity, while for air in is 32,33 m3/s through three in pit such as Adit Sawahluwung amount of 23,32 m3/s, Lurah Sapan I 6,81 m3/s and 2,28 m3/s in Lurah Sapan II. The difference of quantity of air in with air out is 0,43 m3/s which possible caused by adding air in in Mine Vein.
The actual air temperature at work/production J14C front area is 26oC and 27oC for front J15C. Air Temperature decreasing is been done with two method such as putting ice in and out of thermos bottle. For thermos bottle trial it is conducted the number of air temperature decreasing in Front J15C is about 2,5oC – 3oC, while for front J14C is conducted 2oC – 2,5oC. Meanwhile without thermos bottle trial (putting ice in open section), temperature decreasing is 3oC – 3,5oC, and also 3oC in front J14. The result of air temperature decreasing between front J15C and J14C are different, which caused by the difference of duct length and the duct length in J15C is 15 meters and for J14C is 71 meters length. Based on this research, the tenacity of ice is 3 – 3,5 hours.