Kajian Kinerja Main Fan Tambang Emas Bawah Tanah Toguraci PT Nusa Halmahera Minerals, Kabupaten Halmahera Utara, Provinsi Maluku Utara

Muhammad Iqbal, Stefano Munir, Indra Karna Wijaksana

Abstract


Abstract. PT Nusa Halmahera Minerals (NHM) Site Toguraci Mine, according to the sediment type characteristics of the hydrothermal gold ore body which has an epithermal type which causes high temperatures in the mine to range from 38 - 42ºC. Then it is necessary to control the ventilation system. During this time the ventilation system applied is with the exhausting system.The performance of the exhausting system can be assessed with operational parameters between the amount of air pressure (head) and the amount of mine air flow (Quantity), so that it can be determined the main operating point of the fan.The location conditions for mounting the fan according to geographic parameters are at an altitude of 208 meters above sea level with the source of air sucked from the portal with an elevation of 164 meters above sea level and 95 meters above sea level. Based on geological and geotechnical conditions, it has vein deposits in the form of epithermal deposits of the type of hydrothermal deposits which have high temperatures, and are dominated by igneous rock formations which have a high and massive compaction rate. The mining method carried out is underhand cut and fill method and long hole stopping due to the type of sediment in the form of vein and has a low elevation. Environmental conditions are in a variety of diverse flora and fauna and the location is not too barren or dry even though it is far from the location of the river. The main fan operation can be determined by paying attention to the mine curve and the standard curve applied.The performance of the main fan is viewed from the value of air psychrometry in the air ducts, the volume of air sucked, the volume inlet, resistance, water power, the value of performance efficiency, and the comparison of actual conditions and company standards. The performance of the main fan is viewed from three different measurement methods, namely the collar method, mounting bolt and evase. The wet temperature obtained at the time of measurement is 32.3ºC, dry temperature is 34.8ºC with a pressure of 98.60Pa. In the collar method, air volume is 340.5 m3/ s, mounting bolt is 273.18 m3/s, evase 435.18 m3/s (invalid) with standard specification 340 m3/s. The performance of main fan T1 on the collar method is 82.58%, bolt mounting (left) 81.81% (right) 76.45%. For volume inlet with blade slope of 56º with rpm 980 the company's determination for a standard curve with rpm 950 is 187 m3/s with a static pressure fan of 1250 Pa, rpm 990 is 195 m3/s with a static pressure fan of 1360 Pa. In actual conditions, static pressure fans for rpm 950 and 990 obtained 1104 Pa, the inlet volume of rpm 950 was 191 m3/s and the inlet volume with rpm 990 was 204 m3/s. So that the measurement method that can be done is by the collar and ventilation system at PT. NHM is sufficient in the air supply because it is in accordance with the main fan specifications. The operational point based on the fan characteristics curve is at the head of 1.4 kPa and quantity 190 m3/s and the characteristics of the mine are at the head of 1.4 kPa and quantity 180 m3/s.

Keywords: Main Fan, Temperature, Air Volume, Collar, Bolt Mounting, Evase.

 

 

Abstrak. Tambang Site Toguraci PT Nusa Halmahera Minerals (NHM), sesuai dengan karakteristik tipe endapan tubuh bijih emas hidrotermal yang mempunyai tipe epithermal sehingga menyebabkan suhu tinggi dalam tambang berkisar 38 - 42ºC. Maka perlu dilakukan pengontrolan dengan sistem ventilasi. Selama ini sistem ventilasi yang diterapkan adalah dengan sistem exhausting. Kinerja sistem exhausting dapat dinilai dengan parameter operasional antara  jumlah tekanan udara (head) dan banyaknya aliran udara tambang (Quantity), sehingga dapat ditentukan titik operasi main fan. Kondisi lokasi pemasangan main fan menurut parameter geografi yaitu berada pada ketinggian 208 mdpl dengan sumber udara yang dihisap dari portal dengan elevasi 164 mdpl dan 95 mdpl, kondisi iklimnya yaitu tropis basah bersuhu  tahunan rata – rata 28ºC dan kelembaban 88.5%. Berdasarkan kondisi geologi dan geoteknik yaitu mempunyai endapan urat/ vein dengan bentuk endapan epithermal dari tipe endapan hidrotermal yang mempunyai suhu tinggi, serta didominasi oleh formasi batuan beku yang mempunyai tingkat ke kompakkan tinggi dan massive. Metode penambangan yang dilakukan yaitu dengan metode underhand cut and fill dan long hole stopping akibat jenis endapannya berbentuk urat/ vein dan mempunyai elevasi rendah. Kondisi lingkungan berada pada lingkungan yang terdapat flora dan fauna beraneka ragam dan lokasi tidak terlalu tandus atau kering meskipun jauh dari lokasi keberadaan sungai. Operasional main fan dapat ditentukan kinerjanya dengan memperhatikan kurva tambang dan kurva standar yang diterapkan. Kinerja main fan ini ditinjau dari nilai psikrometri udara pada saluran udara, volume udara yang dihisap, inlet volume, resistensi, air power, nilai efisiensi kinerja, serta perbandingan keadaan sebenarnya dan standar perusahaan. Kinerja main fan ini ditinjau dari tiga metode pengukuran yang berbeda yaitu dengan metode collar, bolt mounting dan evase. Suhu basah yang didapatkan pada saat pengukuran yaitu 32.3ºC, suhu kering 34.8ºC dengan tekanan 98.60Pa. Pada metode collar didapatkan volume udara sebanyak 340.5 m3/s, bolt mounting 273.18 m3/s, evase 435.18 m3/s (invalid) dengan standar spesifikasi 340 m3/s. Untuk performa main fan T1 pada metode collar yaitu 82.58%, bolt mounting (left) 81.81% (right) 76.45%. Untuk inlet volume dengan kemiringan blade 56º dengan rpm 980 ketetapan perusahaan untuk kurva standar dengan rpm 950 adalah 187 m3/sdengan fan static pressure 1250 Pa, rpm 990 adalah 195 m3/s dengan fan static pressure 1360 Pa. Pada kondisi aktual, fan static pressure untuk rpm 950 dan 990 didapatkan 1104 Pa, inlet volume rpm 950 sebanyak 191 m3/s dan inlet volume dengan rpm 990 sebanyak 204 m3/s. Sehingga metode pengukuran yang dapat dilakukan yaitu dengan metode collar dan sistem ventilasi di PT. NHM telah mencukupi dalam suplai udara karena sesuai dengan spesifikasi main fan. Titik operasional berdasarkan kurva karakteristik fan berada pada head 1.4 kPa dan debit  190 m3/s dan karakteristik tambang berada pada head 1.4 kPa dan debit 180 m3/s.

Kata Kunci : Main Fan, Suhu, Volume Udara, Collar, Bolt Mounting, Evase.


Keywords


Main Fan, Suhu, Volume Udara, Collar, Bolt Mounting, Evase.

Full Text:

PDF

References


Anonim, 2011, Ventilation of Underground Mines, Draft Code of Practice, Australia.

Anonim, 2014, Mining Services Ventilation Work Book, Australia. PT Nusa Halmahera Minerals.

Apandi, T., dan Sudana, D, 2000, Mandala Geologi Maluku Utara, Dalam Hamilton 1979, Institut Teknologi Bandung, Dep, Umum Research Nasional, Bandung.

Bessho, 1944, Zona Sesar Maluku Utara, Dalam Hamilton 1979, Institut Teknologi Bandung, Dep, Umum Research Nasional, Bandung.

Brake, D.J,2012, Mine Ventilation A Practitioner’s Manual, Sealed Sources Fixed Industrial Gauges and Unsealed Sources-Radioactive Ores & Concentrates. Australia Brisbane.

Chekan G.J., Colinet J.F., dan Grau, R.H, 2006, Impact of Fan Type for Reducing Repairable Dust an Underground Limestone Crushing Facility, Proceedings of the 11th North American/Ninth US Ventilation Symposium, University Park, Pa., June 5-7.

Hamilton, 1979, Zona Sesar Maluku Utara, Institut Teknologi Bandung, Dep. Umum Research Nasional, Bandung.

Hartman, H.L,1982, Mine Ventilation and Air Conditioning, 3rd Edition John Wiley & ons, Inc, Canada.

Hidayat, Wahyu, 2012, Penelitian Geologi Pulau Halmahera, Bina Karya Nusa, Halmahera Utara.

Katili, J. A, 1974, Geologi Daerah Halmahera Barat, Institut Teknologi Bandung, Dep. Umum Research Nasional, Jakarta.

Le Roux, W. L, 1979, Mine Ventilation Notes For Beginners, The Mine Ventilation Society Of South Africa, Africa.

Mc.Pherson, Malcolm J, 1992, Subsurface Ventilation and Environmental Engineering, Chapman and Hall Inc. USA.

Mundell,R. L, 1979, Respirable Dust Control on Longwall Mining Operations in the United States”. Proc. 2nd Int’l Mine Vent. Cong., Mousesset-Jones, P., ed., A.A. Balkema, Rotterdam.

Stefano, Munir, 2005, Ventilasi Tambang, Buku Ajar Program Studi Teknik Pertambangan, Fakultas Teknik, Universitas Islam Bandung.

Plessis,du J.J.L, 2014, Ventilation and Occupational Environment Engineering in Mines, Mine Ventilation Society of South Africa 3rd Edition Revised and Expanded, Africa.

Robert, A, 1960, Chap 13: Ventilation Planning – Estimation of Air Quantity, Mine Ventilation, Roberts, A., ed., Cleaver-Hume Press, Ltd., London.

Sweet, K. A, 1984, Mining 1, Technical Publication Trust, Perth, W. A.




Flag Counter