Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
Not a member yet
1014 research outputs found
Sort by
IMPACTS OF ARTISANAL GOLD MINING AND EFFORTS TO MINIMIZE NEGATIVE IMPACTS TO THE ENVIRONMENT
No full textIndonesia has extensive primary and secondary gold ore deposits that are scattered at several islands. The processing method for gold includes cyanidation, amalgamation and gravity concentration. Amalgamation is one of the most dangerous methods that pollutes the environment. The process is conducted by artisanal gold mining extensively throughout the country and involving around 100.000 miners. The process is started by crushing the ore up to 2-3 cm, then put in the trommel along with Hg and water. The trommel is then rotated for 4-5 hours to produce amalgam (Au-Hg) to be separated from its tailing by panning. The clean Au-Hg, mixed with liquid Hg, is then squeezed to separate the Hg excess. The Au-Hg, mixed with borax is then burnt in a crucible to evaporate its Hg and get the golds bullion (Au-Ag metal). The gold is obtained after the silver within the bullion is leached by HNO3 equipment used for burning the Au-Hg is an open vessel that is operated in the kitchen at which the people also cook the food. This condition is very dangerous for the miner and their families as the Hg vapor is very toxic and can damage human lung. Another problem is that Hg-containing fine tailings are directly discharged to the river. This mercury can pollute the aquatic system and become dangerous for human through food chain. The efforts decreasing the negative effect of artisanal mining employ a retort to burn the amalgam, centralize the trommels; concentrate the gold ores prior to amalgamation. Jig, shaking table, sluice box can be used for upgrading the gold. If tailing with relatively high gold content would be processed by gravity concentration or cyanidation, the location for tailing gold processing should be safe and far from the river and houses
CHEMICAL AND PHYSICAL PROPERTIES OF UPGRADED BROWN COAL
No full textResults of proximate analyses indicate that inherent moisture of the upgraded coals decrease signifi- cantly compared to that of the raw coals. Hence, the calorific value of the upgraded coals increases. The ash content of the upgraded coals did not change obviously due to the UBC process which was conducted at low temperature. However, the volatile matter content increase slightly due to the residue plugs over coal pores to prevent re-absorb of moisture. From ultimate analyses, carbon content of the upgraded coals increases, whereas the hydrogen and oxygen contents decrease. The UBC process hardly effects to the sulfur and nitrogen contents. The equilibrium moisture of the upgraded coals was determined by using ASTM Standard method, most of them were less than 9%. The functional group of C-H and C=O of the upgraded coals were slightly less than that of the raw coals. The aromaticity of coal, all of the upgraded coals was increase. The petrography of both the raw and the upgraded coals indicates that the mean vitrinite reflectance was slightly higher in the upgraded coal compared to that of the raw coal. There was no significant quantity and textural differences of maceral in both coals. The specific surface area of the upgraded coals was lower than that of the raw coals due to the plugging of pore structure and shrinkage by residual oil addition. The briquettability of Upgraded coal briquette according to drop shatter test and compressive strength indicates good characteristics of briquette
REPLACING FUEL OIL BURNER IN A ZINC BATH KETTLE FOR GALVANIZATION PROCESS BY COAL CYCLONE ONE
No full textMost galvanizing industries use fuel oil to maintain a zinc bath temperature within the 440 – 455°C range. The oil burner is used in a heating chamber and the flue gas is then passed into the heating space under a zinc bath kettle at a temperature of 600°C. In this works one of the oil burner would be replaced by a coal burner. The kettle dimension is 12 x 1.5 x 1.8 m for its inner length, width and depth respectively. The heating space under the kettle is divided into two sections, each section is heated by a single oil burner of 50 - 80 litres/hour burning capacity. As there is no access into the heating space to remove the accumulated ash, the employed coal combustion technique should not transfer the ash into this chamber. For this purpose a vertical cyclone coal burner is used in a section with combustion capacity of 100 - 200 kg coal/hour. To minimize ash accumulation, a cyclone dust sepa- rator is connected after the cyclone burner, thus a cleaner flue gas enters the heating chamber. The coal used is a low ash sub-bituminous type of 5,500 kcal/kg at with particle sizes less than 30 mesh. Observation of temperature fluctuation in oil heated and coal heated sections during galvanization process showed that the fluctuation in both sections are in balance, indicating that the coal heating matches fuel oil heating in this system. The fuel used are 124 kg/hour for coal and 60 l/hour for fuel oil. To maintain zinc bath temperature around 430 – 455°C within 7 days galvanizing time operation it is found that fuel consumption is 20,300 kg of coal in the coal heated section and 10,080 l fuel oil in the oil heated section. It means that 1 l fuel oil is equivalent to 2 kg of coal or coal efficiency is 18.2% lower than the oil one in this system. The ash produced by the combustion of coal which trapped by both cyclones is 80% which is accumulated in the burner and 20% in the cyclone dust separator. The energy efficiency of coal is lower than that of the fuel oil since the use of fuel oil is directly burned within heating chamber, otherwise the coal is combusted in a cyclone burner and the flue gas enters the heating chamber after a longer journey through a cyclone dust separator
STIRRING AND NON-STIRRING METHODS USED TO MAKE SYNTHETIC DOLOMITE-BASED EPSOM SALT
No full textThe increasing need of magnesium sulfate heptahidrat by various industries and the limited availabil- ity of this material in nature are two reasons to produce MgSO4.7H2O synthetically. Basically, such a material can be produced from dolomite. A laboratory scale of dolomite-based epsomite making which employed two crystallization processes was conducted. Those were stirring and non-stirring methods and the results showed that stirring one yielded 98.2312 to 98.7244 % MgSO4.7H2O salt. The non-stirring method produced salts of 97.5929 – 99.0378%. Yet prior to salt processing, magne- sium sulfate solution was evaporated at 100 – 110°C to get solution densities around 1.35, 1.38 and1.4 g/ml. The bigger the density the bigger the MgO and SO3 content
ANALISIS BIAYA PENGOLAHAN PASIR ZIRKON (ZrSiO4) MENJADI PASIR ZIRKON BERKADAR ZrO2 ≥65,5 % DAN MICRONIZED ZIRCON
No full textMeningkatkan kadar pasir zirkon (ZrSiO4) menjadi pasir zirkon berkadar ZrO2 ≥65,5% dan berukuran butir lolos saring 60 mesh ≥95% merupakan salah satu upaya untuk meningkatkan nilai tambah dari bahan baku tersebut sesuai dengan amanat dalam Permen ESDM No. 8 Tahun 2015 tentang Perubahan Atas Permen ESDM No.1 Tahun 2014 tentang Peningkatan Nilai Tambah Mineral Melalui Kegiatan Pengolahan dan Pemurnian Mineral di Dalam Negeri. Dengan menggunakan pemisah magnetik dan high tension separator) kadar pasir zirkon dapat ditingkatkan menjadi pasir zirkon berkadar ZrO2 ≥ 65,5 %. Berdasarkan hasil perhitungan finansial terhadap usaha pengolahan pasir zirkon (ZrSiO4) menjadi konsentrat berkadar ZrO2 ≥65,5%, dengan menanamkan modal sebesar Rp.24.307.625.000,- diperkirakan akan memperoleh keuntungan sekarang (net present value, NPV) sebesar Rp.26.201.238.738,-, indek profitabilitas sebesar 1,21 dan indikator tingkat efisiensi (internaI rate of return, IRR) sebesar 29,35% per tahun dengan pengembalian modal pada 3 tahun 5 bulan. Apabila diolah menjadi micronized zircon, dengan bermodalkan Rp.59.066.750.000,- ternyata mendapatkan NPV sebesar Rp.94.154.606.887,-, indek profitabilitas sebesar 1,38, dan indikator tingkat efisiensi (IRR) sebesar 25,60% per tahun dengan pengembalian modal setelah 2 tahun 9 bulan. Berdasarkan perhitungan di atas, usaha pengolahan pasir zirkon untuk menghasilkan micronized zircon tersebut layak untuk diusahakan. Membangun pabrik pengolahan micronized zircon jauh lebih menguntungkan karena nilai tambahnya 2 kali lebih besar dibandingkan dengan hanya mengolahnya menjadi konsentrat zirkon berkadar ZrO2 minimum 65,5%
ANALISIS SWOT DALAM PENGELOLAAN SUMBERDAYA MINERAL DAN BATUBARA INDONESIA SERTA PROSPEKNYA DALAM MENGHADAPI MASYARAKAT EKONOMI ASEAN (MEA)
No full textMenghadapi tantangan Masyarakat Ekonomi ASEAN (MEA), diperlukan sebuah kebijakan dan terobosan yang baru bagi Indonesia khususnya bagi sektor pertambangan mineral dan batubara sehingga memiliki daya saing yang tinggi dan mampu menguasai pasar, di antaranya peningkatan kemampuan teknologi, melakukan inovasi, dukungan lembaga keuangan, perbaikan infrastruktur dan logistik, pembangunan industri pendukung, peningkatan mesin pengolahan bahan baku, dukungan energi, ketersediaan informasi dan kebijakan ekspor produk yang bernilai tambah. Tujuan kajian adalah diperolehnya rumusan strategi sektor pertambangan mineral dan batubara Indonesia dalam menghadapi Masyarakat Ekonomi ASEAN (MEA) yang sudah berjalan sejak akhir tahun 2015. Metodologi kajian adalah dengan menganalisis data sekunder dan studi literatur menggunakan analisis Strength, Weakness, Opportunities and Threat (SWOT). Hasil analisis menunjukkan, strategi yang harus diambil sektor pertambangan mineral dan batubara Indonesia antara lain, strategi SO yaitu strategi dengan mendayagunakan sumberdaya manusia (SDM) yang berkualitas dan profesional serta penggunaan teknologi yang modern untuk memanfaatkan sumber daya dan cadangan mineral dan batubara yang dimiliki. Strategi ST, antara lain dengan mendayagunakan SDM yang berkualitas dan profesional serta penggunaan teknologi yang modern untuk menghadapi ancaman persaingan yang tinggi dan untuk menghadapi kekurangan input bahan baku akibat tidak adanya hambatan ekspor. Strategi WO, strategi dengan memperbaiki segala kelemahan, antara lain memperbaiki infrastruktur, mengatasi kekurangan energi untuk menghasilkan produk yang berdaya saing tinggi dalam rangka meraih peluang pasar yang besar dan untuk memasok bahan baku industri dalam negeri. Sedangkan strategi WT yaitu mempercepat pembangunan infrastruktur, pembangunan energi untuk menghasilkan produk yang berdaya saing tinggi untuk menghadapi ancaman persaingan yang tinggi dan untuk menghadapi ancaman kekurangan bahan baku industri di dalam negeri. Hasil analisis dapat dijadikan masukan kebijakan dalam upaya meningkatkan daya saing sektor ini dalam menghadapi sektor sejenis di antara negara-negara ASEAN lainnya