Elfida Moralista
Teknik Pertambangan, Fakultas Teknik, Universitas Islam Bandung

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Pengaruh Getaran Peledakan terhadap Kestabilan Lereng di Tambang Emas PT J Resources Bolaang Mongondow (JRBM) Site Bakan Giovani Musdika Budiana; Yuliadi; Elfida Moralista
Bandung Conference Series: Mining Engineering 81 -88
Publisher : UNISBA Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29313/bcsme.v6i2.24397

Abstract

Abstract.Blasting is an essential operation in open-pit gold mining that generates ground vibration and may affect slope stability. This study aims to analyze blasting vibration characteristics, evaluate the relationship between Scaled Distance (SD) and Peak Particle Velocity (PPV), and assess the effect of blasting vibration on slope stability at PT J Resources Bolaang Mongondow Site Bakan. The study used 32 blasting records consisting of monitoring distance, explosive charge per delay, PPV, Peak Particle Acceleration (PPA), and vibration frequency. The relationship between SD and PPV was analyzed using the United States Bureau of Mines (USBM) approach, while slope stability was evaluated using the Bishop Simplified and Janbu Simplified methods with maximum horizontal acceleration as the dynamic load. The results show that PPV ranged from 0.127 to 1.805 mm/s and the relationship between SD and PPV was weak, indicating that SD alone could not accurately predict blasting vibration. Dynamic analysis showed only a slight reduction in the slope safety factor, indicating that blasting vibration had a limited influence on slope stability, while slope geometry and rock mass characteristics remained the dominant controlling factors. Abstrak. Kegiatan peledakan pada tambang terbuka menghasilkan getaran tanah yang berpotensi memengaruhi kestabilan lereng. Penelitian ini bertujuan menganalisis karakteristik getaran peledakan, mengevaluasi hubungan Scaled Distance (SD) dengan Peak Particle Velocity (PPV), serta menganalisis pengaruh getaran peledakan terhadap kestabilan lereng di PT J Resources Bolaang Mongondow Site Bakan. Penelitian menggunakan 32 data hasil pengukuran getaran yang meliputi jarak pengukuran, isian bahan peledak per waktu tunda, PPV, Peak Particle Acceleration (PPA), dan frekuensi getaran. Hubungan SD dan PPV dianalisis menggunakan pendekatan United States Bureau of Mines (USBM), sedangkan analisis kestabilan lereng dilakukan menggunakan metode Bishop Simplified dan Janbu Simplified dengan beban percepatan horizontal maksimum. Hasil penelitian menunjukkan bahwa nilai PPV berkisar antara 0,127–1,805 mm/s dan hubungan SD terhadap PPV tergolong lemah sehingga belum dapat digunakan sebagai satu-satunya parameter prediksi getaran. Analisis dinamis menunjukkan bahwa getaran peledakan hanya menyebabkan penurunan faktor keamanan lereng yang relatif kecil, sehingga geometri lereng dan karakteristik massa batuan menjadi faktor yang lebih dominan dalam mengendalikan kestabilan lereng.
Evaluasi Kinerja Jig Sekunder pada KIP Timah Duang Dee 4 Farras Sava Bagaskara; Elfida Moralista; Sriyanti
Bandung Conference Series: Mining Engineering 89 - 96
Publisher : UNISBA Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29313/bcsme.v6i2.24417

Abstract

Abstract. At the Mitra Duang Dee 4 Tin Production Dredger (KIP) operating in the Kelambui Offshore Area, South Bangka Regency, Bangka Belitung Islands Province, the stroke length and stroke frequency of the secondary jig are presumed to be inconsistent with the company's Standard Operating Procedures (SOP). This condition is expected to result in the recovery of the secondary jig not meeting the company's required standard. Therefore, this study aims to determine the characteristics of the processed feed, evaluate the performance of the secondary jig, and identify measures to optimize its performance in terms of recovery. This study employed a quantitative research method based on 24 tests conducted over three consecutive days on the secondary jig. The analyzed parameters included feed weight, concentrate weight, jig stroke frequency, jig stroke length, and the tin (Sn) grades of the feed and concentrate. The performance of the secondary jig was evaluated using two main indicators, namely recovery and concentrate Sn grade, which were then compared with the company's established standards. The results showed that the Sn grade of the concentrate ranged from 71.12% to 74.98%, exceeding the company's minimum standard of 20%. In contrast, the recovery ranged from only 31.55% to 57.47%, which remained significantly below the company's target of 96%. Therefore, adjustments to the operating parameters of the secondary jig, particularly the stroke length and stroke frequency, are required to comply with the company's Standard Operating Procedures and improve both recovery and the overall performance of the secondary jig.   Abstrak. Pada Kapal Isap Produksi (KIP) timah Mitra Duang Dee 4 di Laut Kelambui, Kabupaten Bangka Selatan, Provinsi Kepulauan Bangka Belitung, diduga panjang dan jumlah pukulan pada alat jig sekunder belum sesuai dengan standar operasional prosedur perusahaan. Kondisi tersebut diperkirakan menyebabkan nilai recovery jig sekunder belum mencapai standar perusahaan. Penelitian ini bertujuan mengetahui karakteristik feed yang diolah, mengevaluasi kinerja, serta mengoptimalkan kinerja alat jig sekunder terhadap nilai recovery. Metode penelitian menggunakan analisis kuantitatif berdasarkan 24 kali pengujian selama 3 hari pada alat jig sekunder. Parameter yang dianalisis meliputi berat feed, berat konsentrat, jumlah pukulan, panjang pukulan, serta kadar Sn pada feed dan konsentrat. Kinerja jig dievaluasi berdasarkan dua parameter utama, yaitu nilai recovery dan kadar Sn konsentrat, kemudian dibandingkan dengan standar yang ditetapkan perusahaan. Hasil penelitian menunjukkan kadar Sn konsentrat berkisar antara 71,12%–74,98%, sehingga telah melampaui standar perusahaan sebesar 20%. Sebaliknya, nilai recovery hanya mencapai 31,55%–57,47%, masih jauh di bawah standar perusahaan sebesar 96%. Oleh karena itu, diperlukan penyesuaian kembali variabel operasi jig sekunder, terutama panjang dan jumlah pukulan, agar sesuai dengan standar operasional prosedur sehingga nilai recovery dan kinerja alat jig sekunder dapat ditingkatkan.
Analisis Produktivitas untuk Meningkatkan Produksi Batu Pasir di CV.Bumi Pasir Makmur Ferdi Eka Putra; Yuliadi; Elfida Moralista
Bandung Conference Series: Mining Engineering 115 - 124
Publisher : UNISBA Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29313/bcsme.v6i2.24512

Abstract

Abstract. CV Bumi Pasir Makmur is a sandstone mining company that operates using the surface mining method in Leles District, Garut Regency, West Java Province, Indonesia. In mining operations, the productivity of loading and hauling equipment plays an important role in achieving the company's production target of 500,000 tons per year. However, queues of dump trucks frequently occur in the crusher area, delaying the material dumping process and preventing the production target from being achieved. As a result, the actual annual production reached only 472,320 tons. This condition increases the hauling equipment waiting time, extends the cycle time, and reduces the efficiency of material hauling operations. Therefore, this study aims to determine the productivity of loading and hauling equipment and to analyze the effect of waiting time on the efficiency of sandstone mining operations at CV Bumi Pasir Makmur. This research employed a quantitative descriptive method through direct field observations. The data consisted of primary and secondary data. The primary data included cycle time, dump truck trips, haul road geometry, rock fragment size, rock density test results, and production targets. The secondary data included the location map, mechanical equipment specifications, and rainfall data. The collected data were analyzed to calculate the productivity of loading and hauling equipment, determine equipment working efficiency, and identify the factors affecting the performance of the mechanical equipment. The results showed that the productivity of the loading equipment was 82.35 tons/hour with a working efficiency of 92.22%, while the productivity of the hauling equipment was 82.22 tons/hour with a working efficiency of 52.59%. The analysis also indicated that the dump truck waiting time at the crusher area reached 256 minutes per day. The high waiting time was primarily caused by the relatively small crusher gap, resulting in dump truck queues during the material dumping process. This condition increased the hauling equipment cycle time and reduced hauling productivity. Based on the study results, the hauling equipment became the production bottleneck because its productivity was lower than that of the loading equipment. Therefore, optimization efforts are required to reduce waiting time and improve hauling equipment productivity in order to support the achievement of the company's production target. Abstrak. CV Bumi Pasir Makmur merupakan perusahaan yang bergerak di bidang penambangan batu pasir dengan metode tambang terbuka (surface mining) yang berlokasi di Kecamatan Leles, Kabupaten Garut, Provinsi Jawa Barat. Dalam kegiatan penambangan, produktivitas alat gali muat dan alat angkut memegang peranan penting dalam pencapaian target produksi perusahaan sebesar 500.000 ton/tahun. Namun, diperkirakan sering terjadi antrian dump truck pada area crusher yang memperlambat proses penumpahan material sehingga target produksi belum tercapai. Produksi aktual yang diperoleh hanya sebesar 472.320 ton/tahun. Kondisi tersebut mengakibatkan meningkatnya waktu tunggu (waiting time) alat angkut, bertambahnya cycle time, serta menurunnya efisiensi kegiatan pengangkutan material. Oleh karena itu, penelitian ini bertujuan untuk mengetahui produktivitas alat gali muat dan alat angkut serta mengkaji pengaruh waktu tunggu terhadap efisiensi kegiatan penambangan batu pasir di CV Bumi Pasir Makmur. Metode penelitian yang digunakan adalah metode deskriptif kuantitatif melalui pengamatan langsung di lapangan. Data yang digunakan terdiri atas data primer dan data sekunder. Data primer meliputi waktu edar (cycle time), ritase dump truck, geometri jalan angkut, ukuran bongkah, hasil pengujian densitas batuan, serta target produksi. Data sekunder meliputi peta lokasi penelitian, spesifikasi alat mekanis, dan data curah hujan. Data tersebut kemudian diolah untuk menghitung produktivitas alat gali muat, produktivitas alat angkut, efisiensi kerja alat, serta menganalisis faktor-faktor yang memengaruhi kinerja alat mekanis. Hasil penelitian menunjukkan bahwa produktivitas alat gali muat sebesar 82,35 ton/jam dengan efisiensi kerja 92,22%, sedangkan produktivitas alat angkut sebesar 82,224 ton/jam dengan efisiensi kerja 52,59%. Hasil analisis menunjukkan bahwa waktu tunggu (waiting time) dump truck pada area crusher mencapai 256 menit/hari. Tingginya waktu tunggu tersebut diperkirakan disebabkan oleh ukuran gap crusher yang relatif kecil sehingga menimbulkan antrian dump truck pada saat proses penumpahan material. Kondisi tersebut menyebabkan meningkatnya cycle time alat angkut dan menurunkan produktivitas pengangkutan material. Berdasarkan hasil penelitian, alat angkut menjadi faktor pembatas (bottleneck) dalam sistem produksi karena produktivitasnya lebih rendah dibandingkan produktivitas alat gali muat. Oleh karena itu, diperlukan upaya optimalisasi untuk mengurangi waktu tunggu (waiting time) sehingga produktivitas alat angkut dapat ditingkatkan guna mendukung pencapaian target produksi perusahaan.