DETERMINATION OF NUCLEAR POWER PLANT SITE IN WEST BANGKA BASED ON ROCK MASS RATING AND GEOLOGICAL STRENGTH INDEX

Indonesian government through the NationalAtomic Energy Agency has planned to build anuclear power plant. One of the proposed sitesis in West Bangka Regency, Bangka BelitungArchipelago Province. The engineering geologyof this area is, however, not fully understood andrequires further investigations. Engineering geology investigations were carried out by assessing therock mass quality and bearing capacity based onfield observation and drilling data. The assessmentwas conducted using Rock Mass Rating (RMR)and Geological Strength Index (GSI) classifications.The rock masses in the study area were dividedinto four units, namely units of sandstone, granite,mudstone and pebbly sandstone. The RMR andGSI values in the study area were influenced by theparameters of discontinuity space density, the slopeof discontinuity orientation, grade of weatheringand groundwater conditions. The assessment showsthat the granite unit had the best quality which wasshown by a 53 average RMR value and 66 GSIvalue. Based on the average RMR value, the graniteunit was estimated to have cohesion value between0.2 and 0.3 MPa, friction angle between 25° and35°, and allowable bearing pressure between 280and 135 T/m2. Based on the GSI value, the graniteunit was estimated to have uniaxial compressivestrength value between 1.0465 and 183.8 MPa, ten-sile strength between (-0.0122) and (-5.2625) MPa,rock mass strength values between 24.5244 and220.351 MPa, and modulus of deformation withina range of 1.73 - 86.68 GPa. The Granite Unit wasconsidered to be the most appropriate location forthe nuclear power plants

Analisis Ekonomis Sewa atau Beli Alat Excavator pada Kegiatan Produksi Bijih Timah PT Prima Timah Utama, Desa Cit, Kabupaten Bangka

Fulfilling the annual production target of PT Prima Timah Utama based on the 2019 Work Plan and Budget of 1,100,000 m3 requires the procurement of adequate mining equipment both in terms of quantity and production capacity, especially excavators. The equipment procurement plan is estimated by calculating the need for tools using a sample of 30 distribution time data, 9-time constraints data, and some supporting calculation data that results in tool requirements. The cost of ownership of the equipment to be compared with the rental cost is obtained from the purchase price, interest, residual value and economic life of the equipment, the cost comparison is then analyzed using the Net Present Value method. The calculation results show that PT Prima Timah Utama must add 2 units of CAT 320D2 excavator for overburden stripping and wash with an estimated equipment cost of Rp. 2,224,076,433.6 for 2 units of new equipment and Rp. 2,541,131,520 for 2 units of rental equipment where the difference between the rental and purchase equipment is Rp. 317,055,086.4 for one year of work. The result of the analysis with the evaluation of NPV investment has a value of Rp. 32,313,773,567.7 or >0 which states that the investment is declared feasible

Kajian Teknis Geometri Peledakan dan Powder Factor Terhadap Fragmentasi di PT Semen Padang Indarung

This research is studying about rock fragmentation from blasting result in Front Existing PT Semen Padang Sumatera Barat which shows that there are unmatch size of blasting fragmentation from its target appointed by PT Semen Padang. This research is also study about blasting geometry that represent in burden value dan powder factor which used in the process. The methods used are quantitative and qualitative, that are by studying blasting geometry and powder factor from field observation result and calculating blasting fragmentation size which generated by Software Split- Desktop V.2.0. Blasting fragmentation size analysis in Front Existing is done by applying 4 m burden value, average fragmentation result as much 27.74 cm, and with 4.5 m burden value result as much 30.34 cm, and then with 5 m burden value result as much 29.26 cm while the effect of powder factor against rock fragmentation size in the research obtained using powder factor value as much 0.34 kg/m3, average fragmentation result in 27.6 cm, and with 0.37 kg/m3 powder factor resulting average fragmentation in 32.29 cm, and then with 0.44 kg/m3, the average fragmentation result as much 53.83 cm. Blasting recommendation that can be applied by looking at the research result is that using 4 m burden value to get average fragmentation size as much 27.74 cm, and powder factor value that is usable as much 0.34 kg/m3 in order to get 27.6 cm average fragmentation siz

EFEKTIVITAS DESAIN STOCKPILE PENAMBANGAN BATUGRANIT UNTUK MENCAPAI TARGET PRODUKSI 40.000 TON/BULAN PADA PT BUMIWARNA AGUNG PERKASA

Penambangan granit di PT Bumiwarna Agung Perkasa yang berlokasi di Desa Air Mesu Timur, Kabupaten Bangka Tengah, Provinsi Bangka Belitung, menggunakan metode penambangan quarry. Pada proses penimbunan akhir di stockpile terdapat beberapa kendala yaitu ketidakteraturan timbunan pada setiap produk. Oleh karena itu, perlu dilakukan penataan ulang stockpile agar proses pengangkutan alat transportasi menjadi lancar. Dalam penelitian ini digunakan beberapa metode seperti pengukuran langsung menggunakan total station, menghitung loss material yang terjadi pada crusher, dan menggunakan metode trial and error pada proses desain stockpile untuk memperkirakan kapasitas penyimpanan hingga 40.000 ton, berdasarkan target produksi bulanan PT Bumiwarna Agung Perkasa. Berdasarkan hasil pengukuran secara langsung menggunakan total station didapatkan volume total aktual di stockpile sebesar 28.029,95 ton / m3. Perhitungan loss material pada mesin penghancur primer sebesar 8,46% dengan efisiensi kerja sebesar 28,02%, sedangkan mesin penghancur sekunder memiliki loss material sebesar 12,38% dengan efisiensi kerja sebesar 46,18%. Rancangan timbunan pada timbunan dibagi menjadi 2 jenis timbunan, yaitu tanggul berbentuk kerucut dan limas terpancung. Pada timbunan berbentuk kerucut ditemukan volume total sebesar 2.757,93 ton / m3, pada desain timbunan berbentuk limas terpancung terdapat total volume sebesar 24.483,1 ton / m3. Hasil perhitungan dilakukan sesuai dengan target produksi bulanan PT Bumiwarna Agung Perkasa dengan target 40.000 ton / bulan

Studi Unsur Radioaktif Thorium (Th) dan Uranium (U) di Pulau Bangka

As one of the island that producing tin ore mineral (cassiterite), Bangka Island has probably a bigpotential of tin associated mineral that contains radioactive elements like Thorium (Th) and Uranium(U). Th and U can be one of potential future prospect elements expecially for nuclear energy. Th andU elements bearing minerals in Bangka Island not yet exploited. They take out from the tin ore miningand becoming tailing, and then through the surface water flows or shallow sea water as sediment. Thestudy goal is to getting the number of radioactive Th and U elements using surface sediment sampleand then interpretation some part of their spatial distribution form. The Surface sediment data hasbeen collected on 2 sites Kolong in Muntok District West Bangka Regency, 3 sites in MerawangDistrict Bangka Regency, 9 sites in Pangkalpinang City, 2 sites in Central Bangka Regency and 2sites in South Bangka Regency. Chemistry analysis of sediments for identification the presence of Thand U elements. Radioactive element of Uranium (U) almost presence at all shallow surfacesediment 4.842 - 229.2 ppm except nul in 1 sample. Thorium (Th) just presence in a part of sedimentsample. One site as especially case study Kacang Pedang Retention Ponds, shows Th and Uradioactive elements has the heterogenity spatial pattern.As one of the island that producing tin ore mineral (cassiterite), Bangka Island has probably a bigpotential of tin associated mineral that contains radioactive elements like Thorium (Th) and Uranium(U). Th and U can be one of potential future prospect elements expecially for nuclear energy. Th andU elements bearing minerals in Bangka Island not yet exploited. They take out from the tin ore miningand becoming tailing, and then through the surface water flows or shallow sea water as sediment. Thestudy goal is to getting the number of radioactive Th and U elements using surface sediment sampleand then interpretation some part of their spatial distribution form. The Surface sediment data hasbeen collected on 2 sites Kolong in Muntok District West Bangka Regency, 3 sites in MerawangDistrict Bangka Regency, 9 sites in Pangkalpinang City, 2 sites in Central Bangka Regency and 2sites in South Bangka Regency. Chemistry analysis of sediments for identification the presence of Thand U elements. Radioactive element of Uranium (U) almost presence at all shallow surfacesediment 4.842 - 229.2 ppm except nul in 1 sample. Thorium (Th) just presence in a part of sedimentsample. One site as especially case study Kacang Pedang Retention Ponds, shows Th and Uradioactive elements has the heterogenity spatial pattern

EVALUASI HASIL PENCUCIAN RAW MATERIAL KAOLIN TERHADAP KEBUTUHAN PRODUKSI UNIT PENGOLAHAN PT ANEKA KAOLINE UTAMA BELITUNG

PT Aneka Kaoline Utama produces kaoline powder through two processes which are washing are washing unit and processing unit. Washing unit does the separation between tailing and kaoline with the extract as the result. The extract contains water and kaoline, then the water reduction will be processed in processing unit. Based on the information, writer evaluates the extract production in washing unit for fulfilling the needs of processing unit in PT Aneka Kaoline Utama using evaluation method and action research method. The steps are sampling raw material (feed), calculating the sediment pond’s dimention and the volume of full pond, sampling tailing in washing unit’s tools, observing the production’s process, and evaluating the needs off kaoline extract. The result of this research shows that raw material in washing unit were 3,847.4 ton in April, 3,606.2 ton in May, 2,594.9 ton June, and 3,890 in July which showed the amound of extract did not reach the target in processing unit. 69.2% of loose material and 21% loosing kaolin in average caused the recovery value in washing unit just reached 30.8%. Because of loose kaoline’s presence in washing unit, writer suggests the increasing of raw material and working hour as big as 27,056.3 ton per hour with 30.8% washing unit’s recovery so the company can produce 8.34 ton kaoline per hour and 4,000 ton kaoline per month

PERENCANAAN PENAMBANGAN TRIWULAN PERTAMA MENGGUNAKAN DATA TOPOGRAFI BASED ON SURVEY DI PT ALLIED INDO COAL JAYA SAWAHLUNTO, SUMATERA BARAT

Perencanaan penambangan short term (Jangka Pendek) yang akan dilakukan penelitian di PT Allied Indo Coal Jaya terfokus pada triwulan pertama Tahun 2020 yaitu pada Bulan Januari, Februari, dan Maret. Pengolahan data menggunakan data design pit plan 2020, persebaran batubara, dan mechanical availability plan sebagai data sekunder. Data primer yang digunakan berupa produktivitas alat gali muat dan angkut, titik koordinat, dan End of Mine (EOM) Bulan Desember Tahun 2019. Metode pengolahan data dilakukan secara deskriptif, kualitatif, dan kuantitatif. Lapisan seam batubara diarea penelitian terdapat sebanyak 4 lapisan yaitu seam B1, seam B2, seam C1, dan seam C2. Berdasarkan rencana design pit dan target produksi yang telah ditetapkan pihak perusahaan untuk Tahun 2020, maka dilakukan pemotongan setiap blok penambangan untuk triwulan pertama dengan mempertimbangkan model topografi dan batasan penambangan yang hanya mencapai batas floor seam B2 berdasarkan rekomendasi perusahaan. Dari hasil tersebut diperoleh target bukaan tambang pada triwulan pertama sebanyak 1.466.825 m3, overburden sebanyak 1.366.488,46 bcm, tonnase batubara sebanyak 100.336,54 ton dengan stripping ratio 13. Berdasarkan parameter tersebut jumlah unit yang dibutuhkan untuk mencapai target yaitu sebanyak 17 unit excavator dengan 73 unit dump truck untuk material overburden dan 1 unit excavator dengan 6 unit dump truck untuk material batubara

DETERMINATION OF NUCLEAR POWER PLANT SITE IN WEST BANGKA BASED ON ROCK MASS RATING AND GEOLOGICAL STRENGTH INDEX

Indonesian government through the National Atomic Energy Agency has planned to build a nuclear power plant. One of the proposed sites is in West Bangka Regency, Bangka Belitung Archipelago Province. The engineering geology of this area is, however, not fully understood and requires further investigations. Engineering geology investigations were carried out by assessing the rock mass quality and bearing capacity based on field observation and drilling data. The assessment was conducted using Rock Mass Rating (RMR) and Geological Strength Index (GSI) classification. The rock mass in the study area was divided into four units, namely Units of Sandstone, Granite, Mudstone and Pebbly Sandstone. The RMR and GSI values in the study area are influenced by the parameters of discontinuity space density, the slope of discontinuity orientation, grade of weathering and groundwater conditions. The assessment shows that the Granite Unit has the best quality which is shown by the average RMR value of 53 and GSI value of 66. Based on the average RMR value, the Granite Unit is estimated to have cohesion value between 0.2 and 0.3 MPa, friction angle between 25° and 35°, and allowable bearing pressure between 280 and 135 T/m2. Based on the GSI value, the Granite Unit is estimated to have uniaxial compressive strength value between 1.0465 and 183.8 MPa, tensile strength between (-0.0122) and (-5.2625) MPa, rock mass strength values between 24.5244 and 220.351 MPa, and modulus of deformation within a range of 1.73–86.68 GPa. The Granite Unit is considered to be the most appropriate location for the nuclear power plants. Keywords: Nuclear power plant foundation, geological strength index, rock mass rating, rock mass qualit

Kajian Teknis Sistem Jaringan Ventilasi Tambang Ciurug Level 600 PT Aneka Tambang Tbk UBPE Pongkor

According to field observation result the average dry temperature and wet temperature around between 23 – 30 ºC, with relative humidity around 83 - 93 % and contain 20.9 % O2, 4 ppm CO, on the front production there are 2 cross cut XC 636 and XC 644 have high temperature that reach 31 ºC and 100 % relative humidity. The acquired field data contain dry temperature, wet temperature, wet bulb global temperature, air velocity, and tunnel dimension so then effective temperature, work efficiency and work climate threshold value can be calculated. The result calculation get effective temperature is acquired 29 – 30 ºC, work efficiency 79 - 62 %, and climate threshold value with work arrangement as much 0 - 50 %. Technical problem on the field which causes high temperature is air recirculation from dirty air exhaust from XC 636 that is opposite with clean air direction from fan 75 kW, recirculation on access 644 from booster fan 37 kW located before XC 637 which results in increasing dirty air quantity into front production plus the second front with water puddles from drilling front roof droplets. Effort made on access XC 644 that is fan 75 kW replaced with fan 90 kW, and the tip of flexible duct extends after RC 7 so that the airflow doesn’t mix with exhaust from XC 636, aside from that booster fan 37 kW after XC 637 is moved so it help sucking dirty air from front XC 644, it can resolve air recirculatio

Technical Study of Blasting Geometry and Powder Factor of Fragmentation at Pit 3 Banko Barat PT Bukit Asam Tbk

Mining PT Bukit Asam Tbk is one of the company that works in coal mining. One of the demolition activities in PT Bukit Asam Tbk is overburden stripping using drilling method and blasting. The success rate of blasting activity can be seen from the fragmentation as the blasting result, where the material size is equally spread is better than boulder. On Pit 3 Banko Barat, blasting using stemdeck results with uneven fragmentation size in condition of same powder factor and burden. This is caused by different rain intensity. Rainfall is causing blasting hole to be wet and decreasing the blasting capabilities of explosives. Blasting using stemdeck results in fragmentation average of 27.19 cm. Blasting without stemdeck based on same burden 8 m, results in fragmentation average of 46.46 cm and fragmentation size chart is obtained that shows increasing value as the powder factor from blasting geometry. That thing is contradictory with theory that the greater powder factor will result in uneven fragmentation size because it is connected with explosives usage. This condition is caused by the same doing to different rock structure on mining location in making blasting geometry design. Blasting without stemdeck based on same powder factor 0.16 kg/m3, results in fragmentation average of 66.26 cm and fragmentation size chart is obtained that is increasing as the value of burden. Smallest fragmentation value in average of 25.12 cm with 8 m burden and 0.17 kg/m3 powder factor. So if smaller fragmentation is needed in the future, then it is recommended to use smaller burden in making blasting geometry design