Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
Not a member yet
1014 research outputs found
Sort by
MAGNETIZING ROASTING OF IRON LATERITE ORE BY SUB-BITUMINOUS COAL AS REDUCTANT
No full textThe overburden of Pomalaa’s laterite ore is characterized by its high content of iron with average Fe content of 41.8 % and can be classified as iron cap deposit. As a significant iron ore resource to be used as raw material for iron and steel industry, upgrading of laterite ore is necessary to meet the requirement for iron making. The ore was treated by magnetized roasting technique followed by mag- netic separation to produce high iron content of magnetic concentrate. The ore were dominated by limonite iron minerals and has low magnetic property. However, roasting reduction treatment increased the magnetic properties of the ore due to transformation of magnetite
GEOLOGICAL INFLUENCE ON QUALITY OF SELECTED TERTIARY BARITO COAL
No full textType and rank variation within Tertiary Barito coals of Tanjung Formation were analyzed by petro- graphic examination of ten coal samples. Vitrinite, common liptinite and rare inertinite and mi-neral matter dominate all the coals. Vitrinite macerals are dominated by detrovitrinite and telovitrinite. Resinite, cutinite and sporinite are the dominant liptinite macerals in the coals. Inertinite macerals in the coals comprise semifusinite, sclerotinite and inertodetrinite. Mineral matter consists mainly of clay and pyrite. Liptinite and inertinite contents within coals are systematically related to vitrinite content. The liptinite and inertinite contents decrease with increase of vitrinite content. The liptinite content is not related to the inertinite content. Vitrinite reflectance of Palaeogene coals ranges from 0.53% to 0.64% or sub-bituminous to high-volatile bituminous ranks, respectively, as classified by the Australian standards, and of the Neogene ones varies between 0.30% and 0.47%, classified as brown coal and sub-bituminous ranks, respectively. The slight change in vitrinite reflectance from the top to the base of the sequence is due to the thicker cover/overburden on the high rank coals. Similarities and differ- ences in the type and rank of the coals reflect their geological setting
ANALISIS POLA DISTRIBUSI LOGISTIK DAN INFRASTRUKTUR BATUBARA UNTUK PLTU SKALA KECIL
No full textDalam Rencana Usaha Penyediaan Tenaga Listrik (RUPTL) tahun 2013 – 2022, PT. PLN (Persero) berencana membangun Pembangkit Listrik Tenaga Uap (PLTU) skala kecil dengan kapasitas antara 3 - 25 MW sebanyak 56 unit. Lokasi PLTU yang akan dibangun tersebar di seluruh Indonesia, jumlah batubara yang dibutuhkan setiap tahun sebesar 4.821.453 ton. Permasalahannya adalah darimana dan dengan cara bagaimana batubara tersebut diperoleh karena PLTU yang akan dibangun di beberapa daerah tersebut tidak memiliki atau jauh dari lokasi sumber daya batubara. Di lain pihak, sumber batubara Indonesia saat ini sebesar 126,60 miliar ton dengan cadangan tercatat sebanyak 32,26 miliar ton, terdiri dari cadangan terkira sebanyak 23,99 miliar ton dan terbukti sebanyak 8,27 miliar ton dengan lokasi yang tersebar di beberapa wilayah antara lain di Pulau Kalimantan yaitu sebesar 17,19 miliar ton (atau 56,31% dari total) dan 43,69% tersebar di Pulau Sumatera serta sisanya tersebar di Jawa, Maluku dan Papua, yang secara umum sudah diusahakan. Tujuan penelitian adalah merumuskan model pemasokan-permintaan yang paling ekonomis, sedangkan metode yang digunakan adalah analisis model pemasokan-permintaan berdasarkan pemrograman linear. Dari hasil penyaringan terhadap sejumlah perusahaan penghasil batubara, terpilih 19 perusahaan pemasok yang memenuhi kriteria sebagai calon pemasok kebutuhan batubara pada 56 PLTU yang direncanakan, selanjutnya setelah semua variabel-variabel dimasukkan ke dalam model pasokan-permintaan, diperoleh 18 alternatif pasokan kebutuhan. Moda transportasi yang digunakan bervariasi, melalui jaur darat, sungai dan laut, sedangkan infrastruktur logistik batubara yang dapat digunakan adalah alat angkut jenis tongkang 300 feet dengan kapasitas muat 5000 ton. Total frekuensi pelayanan pemasokan batubara antara 6 sampai dengan 30 kali (roundtrip) dalam setahun, tergantung jumlah kebutuhan masing-masing PLTU. Infrastruktur lainnya untuk mendukung kegiatan operasi di pelabuhan PLTU skala kecil antara lain dermaga, stockpile berikut shiploader, conveyor, stacker & reclaimer,crusher, blender dan mixer. Hasil kajian ini sangat penting sebagai masukan dalam merumuskan kebijakan pola distribusi logistik dan infrastruktur batubara untuk PLTU Skala kecil.
ANALISIS PENETAPAN TARGET LOCAL CONTENT BARANG PADA KEGIATAN USAHA PERTAMBANGAN
No full textAnalisis muatan lokal (local content) merupakan salah satu upaya untuk mengidentifikasi peluang peningkatan keterkaitan antara pengusahaan pertambangan dengan sektor-sektor ekonomi di dalam negeri, permasalahan yang muncul serta alternatif pemecahannya. Teknik pengumpulan data menggunakan teknik sampling, sementara itu model pengolahan dan teknik analisis menggunakan pendekatan statistik deskriptif, model perhitungan muatan lokal dan model analisis tren. Hasilnya berupa gambaran dan target muatan lokal serta rekomendasi masukan dalam penyusunan rancangan peraturan tentang penggunaan barang produksi dalam negeri pada kegiatan usaha pertambangan. Salah satu isu yang diperoleh adalah tentang pentingnya menetapkan target (roadmap) peningkatan muatan lokal pada kegiatan usaha pertambangan. Pengukuran muatan lokal barang dilakukan pada beberapa perusahaan, yaitu PT Newmont Nusa Tenggara (PT NNT), PT Freeport Indonesia (PT FI), PT Meares Soputan Mining (PT. MSM) dan PT J. Resources Bolaang Mongondow (PT JRBM), selama periode 5-7 tahun terakhir. Hasilnya menunjukkan bahwa muatan lokal pada PT NNT semula 39,0%, naik menjadi 75,8%; PT FI dari sekitar 36%, naik menjadi 71%; PT JRBM dari 71,18%, naik menjadi 81,35%, sedangkan PT MSM dalam periode tersebut melakukan kegiatan pengembangan investasi, sehingga cenderung menurun dari 94% menjadi 85%. Perkembangan tingkat muatan lokal PT FI mengikuti regresi linier dengan persamaan y=8,1x+9,4 sedangkan untuk PT NNT dan PT JRBM berturut-turut adalah y=5,5x+28,2 dan y=0,8x+76,1. Dari ketiga persamaan tersebut selanjutnya dijadikan dasar dalam menetapkan target peningkatan muatan lokal. Ada 3 kelompok tingkat capaian muatan lokal, 30% -50%, 50% -70%, dan 70%-90%, dengan masing-masing target tingkat kenaikan yang diusulkan masing-masing adalah 10,0%, 6,5%, dan 3,0% per tahun. Target tersebut dengan asumsi dalam keadaan normal, sedangkan target muatan lokal barang maksimal adalah kondisi kemampuan produksi barang di dalam negeri
INDICATION OF GRAIN ENLARGEMENT IN DRY GRINDING PROCESS USING A ROD MILL, OBSERVED AT INCREASED MILLING TIME
No full textThe aim of the study is to determine whether size distribution and grain properties of the milling product can be controlled by rod size, milling time or a combination of both. Milling experiments had been carried out using rod of 9.8, 23.8, and 46.0 cm respectively as well as milling time of 30, 60, 210, 360 and 600 minutes. Grain properties were studied by sieve analysis and binocular microscope. The entire rod sizes and 30-minutes mill- ing time yielded grain enlargement as a result of van der Waals forces among colliding particles with the help of dampness as a binding media. The longer the milling time, the more coalesce the grains. It is also known that the smaller the particles, the lesser the particle density but the brighter the grain appearance. For all combina- tions, grain enlargement took place within size of -60 +100# showing the highest weight proportion in the period of 286.54 minutes
REVIEWING THE PROPERTIES OF RARE EARTH ELEMENT-BEARING MINERALS, RARE EARTH ELEMENTS AND CERIUM OXIDE COMPOUND
No full textOf the 17 rare earth elements (REEs), 15 belong to the chemical group called lanthanides, plus yttrium and scandium. The lanthanides consist of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Cerium is one of the most abundant REEs, comprises more of the earth’s crust than copper or lead. At least, there are 29 potential REE-bearing minerals. Basnasite, monazite and xenotime are among them and serve as the most exploited minerals. The REEs are mostly applied for high technology application such as computer, telecommunication, nuclear and sophisticated instruments for exploring the outer space
DEVELOPMENT OF NEW EQUATIONS FOR ESTIMATING GROSS CALORIFIC VALUE OF INDONESIAN COALS
No full textNumerous empirical equations have been published to correlate the gross calorific value (GCV) of coals with the result of proximate or ultimate analysis, however, many researchers continue to propose new equations. One of the reasons is that many existing equations are likely fitted to coal of one region only. This study is aimed to evaluate the applicability of some existing equations to calculate GCV of Indonesian coal and to develop new equations that more accurate to predict the calorific value of Indonesian coal. Ten (10) new GCV formulas based on proximate analysis data of Indonesian coal were generated using SPSS software. They include three (3) equations with one independent variable, four (4) equations with two independent variables, two (2) equations with three independent variables and one (1) equation with four independent variables. The best equation has the following form: GCV= 25.284 (M) + 30.572 (Ash) + 62.127 (VM) + 138.117 (FC) - 2890.095. The result is in agree with previous work that equation involving four independent variables i.e. moisture (M), ash, volatile matter (VM) and fixed carbon (FC) provides the most accurate estimation of GCV. The new equation when it is used for calculating GCV of Indonesian coals gives more accurate results than that of some existing equations in the literatures
