Kajian Teknis Sistem Penerisan Tambang Di Front 2 TB 2.2 Tempilang Bangka Mitra PT Timah (Persero) Tbk

The Technical Study of Mine Drainage System In Front 2 TB 2.2 Tempilang Large Mine of West Bangka PT Timah (Persero) Tbk’S Partner

Abstract

Tin ore mining activities in Front 2 of 2.2 Tempilang Large Mine was operated by business partner
of PT Timah (Persero) Tbk, PT Bahtera Sarindo Utama used Open Pit Mining Method with mechanical
systems. Open Pit Mining Method would eventually form a large basin, so that would become a place
for air accumulation at the base of mine site, applied drainage system used Repressive Kuruative
Drainage System by allowing water to pour into the mine and then concentrated on the front sump and
they would be removed from the mine using pumping systems. Rainfall data used included a
maximum rainfall data with period of 2005-2014, the calculation of rainfall plans used Gumbel
distribution and calculation of rainfall intensity with Mononobe Equation, but for the period of rain is
taken with the 2-year period. From the research, the existing sump had capability to retain water with a
volume of 79.5 m3 and existing pumps had the capacity of 86.4 m3/h, while the total water poured in
the mine was 2172.588 m3/day with total of catchman area was 64085.442 m2. To improve drainage
system performance on Front 2 of 2.2 Tempilang Large Mine, dimensional sump need to be repaired
with a capacity of 1267.336 m3 to bring outwater volume plan outside of work time (14 hours) and an
alternative pump was add 1 unit of recommendation pump with the same type such as Mitshubisi
6D16 gravel pump (engine) with a pump capacity of 154.8 m3/h, but the actual pump was still being
used so that with the use of two unit pump acquired total pump capacity was 241.2 m3/h with the
lifetime of pumping was 9 hours to remove the water 2172.588 m3/per day.