Rancangan sump dan sistem pemompaan di PIT Barani, Site Martabe Goldmine, PT Agincourt Resources, Sumut
P T Agincourt Resources (PTAR) merupakan perusahaan pertambangan emas yang beroperasi di site Martabe Gold Mine, di desa Aekpining, Kecamatan Batang Toru, Kabupaten Tapanuli Selatan, Provinsi Sumatera Utara. Site Martabe memiliki tiga pit produksi yakni, Pit Purnama, Pit Barani dan Pit Ramba-Joring. Juni 2016 PTAR memulai operasi produksi penambangan di Pit Barani. Penyaliran tambang aktual di pit Barani menggunakan saluran air terbuka dan gorong-gorong. Pada musim penghujan bulan Oktober-Desember 2018, pit Barani mengalami kebanjiran akibatnya kegiatan penambangan terhambat. Oleh karena itu perusahaan merencanakan pembuatan sump dan sistem pemompaan di Pit Barani. Outlet tampungan dari sump direncanakan untuk dialirkan ke TSF. Penelitian ini dilakukan untuk merancang kebutuhan sump dan sistem pemompaan di Pit Barani. Penentuan kebutuhan kapasitas sump dilakukan dengan perhitungan debit Annual Series dengan periode ulang 5 tahun dan rataan durasi hujan 3,8 jam. Setelah itu dihitung kemiringan penampang dasar 4% untuk jagaan terjadinya sedimentasi. Pembuatan sump dirancang dengan volume 11.810 m3 untuk kebutuhan bulan Maret-Mei, 12.300 m3 untuk kebutuhan bulan Juni-Agustus, dan 12.800 m3 untuk kebutuhan bulan September-Desember. Rancangan pemompaan dilakukan dengan pompa Pioneer (PP86C17L71) dan asesoris pipa HDPE 8 inci. Penentuan debit pompa ditentukan berdasarkan debit Partial Series perkuarter penambangan. Rancangan untuk bulan Maret-Mei membutuhkan pipa sepanjang 621,379 m, dengan beda elevasi 16 m, dan target efisiensi pompa 75% direkomendasikan penggunaan pompa pada debit 280 m3/jam pada rpm 1300. Rancangan untuk bulan Juni-Agustus membutuhkan pipa sepanjang 639,247 m, beda elevasi 27 m, dan target efisiensi pompa 75% direkomendasikan penggunaan pompa pada debit 320 m3/jam pada rpm 1500. Rancangan untuk bulan September-Desember membutuhkan pipa sepanjang 701,237 m, beda elevasi 32 m, dan target efisiensi pompa 75% direkomendasikan penggunaan pompa pada debit 360 m3/jam pada rpm 1700.
P T Agincourt Resources (PTAR) is a gold mining company that operates at the Martabe Gold Mine site, in Aekpining village, Batang Toru District, South Tapanuli Regency, North Sumatra Province. Martabe site has three production pits namely, Purnama Pit, Barani Pit and Ramba-Joring Pit. June 2016 PTAR begins mining production operations in the Barani Pit. Actual mine drainage in the Barani pit using open water channels and culverts. In the rainy season in October-December 2018, the Barani pit was flooded as a result of mining activities being hampered. Therefore the company plans to build a sump and pumping system in the Barani Pit. Storage sump outlets from sump are planned to be channeled to TSF. This research was conducted to design the needs of sump and pumping systems in the Barani Pit. Determination of sump capacity requirements is done by calculating the Annual Series discharge with a return period of 5 years and an average rain duration of 3.8 hours. After that the basic cross section slope of 4% is calculated to guard against sedimentation. Making sumps was designed with a volume of 11,810 m3 for March-May needs, 12,300 m3 for June-August needs, and 12,800 m3 for September-December needs. The pumping design was carried out with Pioneer pumps (PP86C17L71) and 8-inch HDPE pipe accessories. Determination of pump discharge is determined based on Partial Series discharges per quarter mining. The design for March-May requires a pipe length of 621,379 m, with an elevation difference of 16 m, and a 75% pump efficiency target is recommended to use a pump at 280 m3 / hr discharge at 1300 rpm. The design for June-August requires a pipe of 639,247 m, different elevation of 27 m, and a 75% pump efficiency target is recommended to use pumps at 320 m3 / hr discharge at 1500 rpm. The design for September-December requires a pipe of 701,237 m, 32 m elevation difference, and a 75% pump efficiency target is recommended for pump use at 360 m3 / hour discharge at 1700 rpm.