scholarly journals Analisis coal losses pada kegiatan penambangan di Pit Inul Middle Panel 3 PT Kaltim Prima Coal

2021 ◽  
Vol 6 (2) ◽  
pp. 57
Author(s):  
Afif Irfandy ◽  
Agus Triantoro ◽  
Sari Melati

Coal Losses merupakan proses hilangnya batubara yang terjadi pada saat proses penambangan berlangsung sampai pada saat pengiriman batubara ke tujuan. Proses penambangan batubara seperti clean up roof batubara, proses pemuatan batubara, serta saat pengangkutan batubara menuju stockpile berpotensi menimbulkan coal losses. PT Kalimantan Prima Coal menetapkan coal recovery criteria sebesar 98,5%, lebih ketat dari yang ditetapkan Kementerian Energi dan Sumber Daya Mineral (ESDM) sebesar 90%. Penelitian ini bertujuan untuk menghitung coal losses pada proses clean up batubara, pemuatan batubara di loading point, dan pengangkutan batubara; mengetahui faktor-faktor yang menyebabkan terjadinya coal losses; dan memberi rekomendasi upaya penanganan coal losses.Penelitian dilakukan di Pit Inul Middle Panel 3 pada PT KPC bulan Mei dan Juni 2019. Ada lima seam batubara yang diamati, yaitu seam  K17LR, K13, K12, K9 dan K4. PT KPC menggunakan survey yang dibandingkan dengan truck count untuk menghitung coal recovery. Total coal losses yang didapat dari setiap seam dibagi menjadi tiga proses penambangan batubara, yaitu coal losses pada saat clean up roof batubara, di loading point, dan saat hauling.Coal Losses yang didapatkan pada seam K17LR bulan Mei dan Juni 2019 sebesar 4,49% dan 3,93%; seam K13 bulan Mei dan Juni 2019 sebesar 2,83% dan 1,47%; seam K12 bulan Mei dan Juni 2019 sebesar 3,57% dan 2,71%; seam K9 bulan Mei dan Juni 2019 sebesar 4,24% dan 4,15%; seam K4 bulan Mei dan Juni 2019 sebesar 4,3% dan 1,11%. Coal losses yang terjadi masih di atas dari kriteria yang diberikan oleh ESDM sehingga masih memenuhi batas kriteria. Persentase coal losses terbesar terjadi di loading point sehingga dilakukan simulasi pengurangan coal losses di loading point. Total losses 19.43% pada Bulan Mei and dan 13.38% pada Bulan Juni berhasil diturunkan menjadi 9,44% and 6,98%. Kata-kata kunci : batubara, recovery, clean up, loading point, hauling

2012 ◽  
Vol 178-181 ◽  
pp. 1442-1447 ◽  
Author(s):  
Ai Hong Kang ◽  
Wu Hong Zhang

To explore the relationships between the performances and microstructures of modified asphalt, in the tests, one kind of basic asphalt、two kinds of modifiers and four kinds of modifiers content were selected to prepare modified asphalt. The SBS modified asphalt performances such as softening point, viscosity, Rutting Factor G*/sinδ and the corresponding microstructures with different shearing time were analyzed. The results show that different modifiers have different modification effects on the asphalt,but the change trends of performances and microstructures with the modifier content and shearing time are basically the same. It is also found that there is a good relationship between microstructure and macro performance, the average area of the modifier is closely related to the softening point, total area (or area percentage) and the shape factor of the modifier are suitable to reflect the mechanical behavior of modified asphalts.


Author(s):  
Całus Moszko Joanna ◽  
Iwaszenko Sebastian ◽  
Bajerski Andrzej ◽  
Janoszek Tomasz

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Eryu Wang ◽  
Xiangdong Chen ◽  
Xiaojie Yang

In order to solve the problems of the high cost and time consumption of half coal rock entry driving, low coal recovery rate, and stress concentration on filling support body of retained entry along gob, the innovative 110 mining method based on pressure relief by roof cutting was adopted in 6302 thin coal seam working face of Baoshan Coal Mine. First the technical principle and key technology of this mining method was presented. Then, through theoretical analysis and calculation, engineering experience, and field test, the key parameters such as the length of constant resistance anchor cable, the cutting angle and height of presplitting blasting, the charge structure, and the blocking-gangue support structure were determined and conducted in the retained entry. The broken expanded coefficient varying law of caved gangue with time and space was obtained, which revealed roof movement characteristic. The displacement monitoring curve of the roof and floor indicated that the maximum subsidence of the roof was about 150 mm and the maximum amount of floor heaving was 100 mm, which were quite small. The field monitoring data indicated that the entry retaining effect is good, which indicated that the innovative 110 mining method can be an effective way for reducing the high cost and time consumption of half coal rock entry driving, enhancing the coal recovery rate and preventing the dynamic mine pressure disasters.


2021 ◽  
Author(s):  
Chuang Liu ◽  
Huamin Li

Abstract In the process of longwall top coal caving, the selection of the top coal caving interval along the advancing direction of the working face has an important effect on the top coal recovery. To explore a realistic top coal caving interval of the longwall top coal caving working face, longwall top coal caving panel 8202 in the Tongxin Coal Mine is used as an example, and 30 numerical simulation models are established by using Continuum-based Distinct Element Method (CDEM) simulation software to study the top coal recovery with 4.0 m, 8.0 m, 12.0 m, 16.0 m, 20.0 m and 24.0 m top coal thicknesses and 0.8 m, 1.0 m, 1.2 m, 1.6 m and 2.4 m top coal caving intervals. The results show that with an increase in the top coal caving interval, the single top coal caving amount increases. The top coal recovery is the highest with a 0.8 m top coal caving interval when the thickness of the top coal is less than 4.0 m, and it is the highest with a 1.2 m top coal caving interval when the coal seam thickness is greater than 4.0 m. These results provide a reference for the selection of a realistic top coal caving interval in thick coal seam caving mining.


2019 ◽  
Vol 18 (2) ◽  
Author(s):  
Siti Husnul Hotima ◽  
Dini Hayati

Tujuan yang diharapkan dari penelitian ini adalah ingin menganalisis persediaan bahan baku optimal yang dibutuhkan dengan menggunakan metode Economic Order Quantity (EOQ), menganalisis berapa besar persediaan pengaman (Safety stock), menganalisis kapan waktu yang tepat untuk melakukan pemesanan kembali (reorder point), menganalisis total persediaan bahan baku atau Total Inventory Cost (TIC). Jenis penelitian yang digunakan adalah kuantitatif deskriptif. Teknik pengumpulan data yang digunakan dalam penelitian ini adalah wawancara, observasi, dan dokumentasi. Penelitian dan hasil perhitungan yang dilakukan menunjukkan bahwa persediaan bahan baku setiap tahunnya tidak stabil. Bahan baku yang dibutuhkan oleh perusahaan apabila dihitung menggunakan metode Economic Order Quantity (EOQ) pada tahun 2016 adalah sebesar 11,52 m3 dengan frekuensi pembelian 6 kali per periode (1 tahun). Tahun 2017 sebesar 9,90 m3 dengan frekuensi pembelian 6 kali per periode (1 tahun). Persediaan pengaman (safety stock) pada tahun 2016 adalah sebesar 16,48 m3. Pada tahun 2017 sebesar 11,25 m3. Titik pemesanan kembali (reorder point) pada tahun 2016 adalah sebesar 17,18 m3. Pada tahun 2017 sebesar 13,1 m3. Total biaya persediaan bahan baku yang dihitung menurut Economic Order Point (EOQ) lebih sedikit dibandingkan dengan yang dikeluarkan oleh perusahaan, maka ada penghematan biaya persediaan. Pada tahun 2016 sebesar Rp.110.499.402 dan pada tahun 2017 sebesar Rp.81.655.306. Kata Kunci: Economic Order Quantity (EOQ), Persediaan Pengaman (Safety Stock), Titik Pemesanan Kembali (Reorder Point), Total Biaya Persediaan atau Total Inventory Cost (TIC).


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 934 ◽  
Author(s):  
Jinzhu Hu ◽  
Manchao He ◽  
Jiong Wang ◽  
Zimin Ma ◽  
Yajun Wang ◽  
...  

Gob-side entry retaining by roof cutting (GERRC) employed in a deep inclined thick coal seam (DITCS) can not only increase economic benefits and coal recovery, but also optimize surrounding rock structure. In accordance with the principles of GERRC, the technology of GERRC in DITCS is introduced and a roof-cutting mechanical model of GERRC is proposed to determine the key parameters of the depth and angle of RC. The results show that the greater the RC angle, the easier the caving of the goaf roof, but the length of cantilever beam increases. The depth of RC should account for the dip angle of the coal seam when the angle is above 20°. Increasing the coal seam dip angle could reduce the volume of rock falling of the goaf roof, but increase the filling height of the upper gangue to slide down. According to numerical model analysis of the stress and displacement of surrounding rock at different depths and angles of RC, when the depth of RC increased from 9 m to 13 m, the distance between the stress concentration zone and the coal side is increased. When the angle of RC increased from 0° to 20°, the value of roof separation is decreased. GERRC was applied in a DITCS with 11 m depth and 20° RC angle, and the field-measured data verified the conclusions of the numerical model.


1950 ◽  
Vol 42 (4) ◽  
pp. 626-630
Author(s):  
E. E. Rickert ◽  
W. T. Bishop

2017 ◽  
Vol 107 ◽  
pp. 123-138 ◽  
Author(s):  
Yassine Taha ◽  
Mostafa Benzaazoua ◽  
Rachid Hakkou ◽  
Mohammed Mansori
Keyword(s):  

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