Perancangan pit dan penjadwalan tambang batubara menurut analisis sensitivitas Break Even Stripping Ratio - Diyan Adiatma; Eko Santoso; Sari Melati (Jurnal Himasapta, 2025)
Sektor pertambangan merupakan salah satu sektor usaha yang memiliki potensi pendapatan tinggi, namun juga diikuti oleh tingkat risiko yang besar. Risiko tersebut dapat berasal dari fluktuasi kondisi ekonomi, khususnya perubahan harga komoditas, serta keterbatasan dan karakteristik bahan galian yang ditambang. Oleh karena itu, sebelum kegiatan penambangan dilakukan, diperlukan beberapa alternatif desain pit agar rencana penambangan dapat disesuaikan dengan kondisi ekonomi yang terjadi selama umur tambang. Penelitian ini bertujuan untuk menganalisis sensitivitas Break Even Stripping Ratio (BESR) sebagai kriteria utama dalam perancangan Pit Alfa, merancang Pit Alfa berdasarkan tiga nilai BESR, serta menyusun penjadwalan penambangan untuk masing-masing desain pit. Analisis sensitivitas dilakukan dengan memvariasikan nilai BESR sebesar ±10%. Alternatif rancangan pit disusun dalam tiga skenario, yaitu kondisi yang diharapkan, kondisi peningkatan sebesar 10%, dan kondisi penurunan sebesar 10%. Perancangan pit dilakukan menggunakan perangkat lunak Minescape dengan model topografi dan endapan batubara yang telah tersedia. Geometri lereng Pit Alfa mengikuti geometri lereng yang diterapkan pada Pit Clara. Tahapan penambangan dirancang untuk memenuhi target produksi sebesar 50.000 ton batubara per bulan. Hasil analisis menunjukkan bahwa BESR paling sensitif terhadap perubahan harga batubara. Pada harga batubara USD 42,39/ton, Pit Alfa dirancang dengan BESR 5,31, menghasilkan luas pit 24,4 ha, cadangan batubara 770.135 ton, dan umur tambang 14 bulan. Pada kondisi harga turun 10%, BESR sebesar 4,24 menghasilkan luas pit 18,2 ha, cadangan 546.884 ton, dan umur tambang 11 bulan. Sebaliknya, pada harga naik 10%, BESR sebesar 6,39 menghasilkan luas pit 30 ha, cadangan 936.780 ton, dan umur tambang 18 bulan. Kata kunci : analisis sensitivitas, BESR, penjadwalan tambang, perancangan pit ABSTRACTThe mining sector is one of the industries with high revenue potential; however, it is also associated with significant risks. These risks arise from fluctuations in economic conditions, particularly changes in commodity prices, as well as the availability and characteristics of the mined mineral resources. Therefore, prior to mining operations, several alternative pit designs must be prepared to allow flexibility in adapting to economic conditions throughout the mine life.This study aims to analyse the sensitivity of the Break Even Stripping Ratio (BESR) as a key criterion in the design of Pit Alfa, to develop Pit Alfa designs based on three BESR values, and to establish mining schedules for each pit design. The sensitivity analysis was conducted by varying the BESR parameter by ±10%. Three pit design scenarios were evaluated, representing the expected condition, a 10% increase, and a 10% decrease.Pit design was performed using Minescape software, utilizing available topographic and coal deposit models. The slope geometry of Pit Alfa was designed to follow the slope geometry applied at Pit Clara. Mining stages were developed to achieve a production target of 50,000 tons of coal per month.The results indicate that BESR is most sensitive to changes in coal price. At a coal price of USD 42.39 per ton, Pit Alfa was designed with a BESR of 5.31, resulting in a pit area of 24.4 ha, coal reserves of 770,135 tons, and a mine life of 14 months. When coal prices decrease by 10%, a BESR of 4.24 produces a pit area of 18.2 ha, coal reserves of 546,884 tons, and a mine life of 11 months. Conversely, when coal prices increase by 10%, a BESR of 6.39 yields a pit area of 30 ha, coal reserves of 936,780 tons, and a mine life of 18 months. Keywords: sensitivity analysis, break even stripping ratio, mine scheduling, pit design