Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
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EFFECT OF SULFUR IN THE REDUCTANTS ON SULFIDATION MECHANISM OF NICKEL LATERITE
Get PDFProcessing nickel laterite conventionally, namely by pyrometallurgy method, requires high temperature and energy, results in a costive process. Due to its lower temperature reduction process, selective reduction with additives could be an alternative in nickel ore processing. Additives such as sulfur/sulfate have a critical role in promoting the low melting point phase. Sulfur is also found in coal. Therefore, it is important to investigate the effect of sulfur content in reductant on selective reduction of lateritic nickel ore. In this work, the effect of sulfur content (2.68% and 5% S) in anthracite coal as a reductant on selective reduction of limonitic ore was studied clearly. Nickel ore, reductant and sodium sulfate were mixed homogenously and pelletized up to 10-15 mm in diameter. Pellets were reduced using a muffle furnace at 950 to 1150°C for 60 min. Reduced pellets were crushed into -200 mesh before separating the ferronickel and its impurities using a wet magnetic separation process. The result showed that the anthracite coal with 5% S produced concentrate containing 3.56% Ni with 95,97% recovery, which is higher than 2.68% S. The sulfur content in reductant could replace the addition of sulfur/sulfate as the additives in the selective reduction of lateritic nickel ore
EFFECT OF LOW RANK COAL TEMPERATURE AND MOISTURE CONTENT ON SLOW PYROLYSIS PROCESS
Get PDFThe government of Indonesia has made policies to increase the added value of coal. It can be completed using technology of slow pyrolysis. This study aimed to increase the added value of coal by analyzing the effect of temperature and water content of the feed on slow pyrolysis products. Water content variation in the feed form of coal was 10.57 wt% and 16.86 wt%. Temperature variations in the slow pyrolysis process were 500, 600, 700, and 800 ºC. Result of this research showed that the low moisture content of coal produced more char in the slow pyrolysis process. Based on the variations of the used temperature, a higher temperature of pyrolysis produced fewer char but its calorific value of coal product was also higher. The optimum operating condition was achieved at 500-600 ºC
PENGARUH PENAMBAHAN KATALIS TiO2 TERHADAP SIFAT KIMIA PERMUKAAN KOMPOSIT KARBON AKTIF UNTUK PENYERAPAN GAS SO2
No full textKarbon aktif dan TiO2 mereduksi SO2 melalui proses adsorpsi dan fotokatalitik. Kedua senyawa ini memiliki efektivitas adsorpsi rendah. Untuk meningkatkan aktivitas adsorpsi dilakukan kombinasi teknik adsorben dan fotokatalitik sehingga adsorpsi dapat optimal. Kombinasi dilakukan dengan membuat komposit karbon aktif/TiO2. Batubara dan semi-kokas dicampur dengan perbandingan 7:3 kemudian TiO2 ditambahkan dengan konsentrasi 1, 3, 6, 9 dan 15%. Karbon aktif/ TiO2 dikarbonisasi pada suhu 600 °C selama 1 jam dan diaktivasi pada suhu 900 °C selama 1 dan 2 jam di bawah aliran gas nitrogen. Hasil analisis fourier-transform infrared (FTIR) spectroscopy menunjukkan intensitas serapan gugus fungsi C=O naik sebesar 49,5% pada karbon aktif/TiO2 6% selama 1 jam dan 33,2% pada karbon aktif/TiO2 3% selama 2 jam. Gugus fungsi basa C=O mereduksi gas SO2 yang bersifat asam. Hasil X-ray diffraction (XRD) ditemukan kristal TiO2 anatas dan rutil. Koeksistensi kristal anatas dan rutil lebih efektif daripada anatas dan rutil fase tunggal. Hasil penelitian ini menunjukkan bahwa karbon aktif/TiO2 meningkatkan aktivitas gugus fungsi permukaan karbon aktif dan membentuk kristal TiO2 anatas dan rutil secara bersama
PENGARUH SUHU PROSES HYDRO THERMAL DEWATERING TERHADAP KARAKTERISTIK COAL WATER MIXTURE
No full textBatubara peringkat rendah umumnya mempunyai kadar air bawaan yang tinggi. Sebagai bahan baku pembuatan coal water mixture (CWM), batubara tersebut tidak cocok digunakan sebagai bahan baku karena akan menghasilkan CWM dengan kadar air yang tinggi, sehingga nilai kalor menjadi rendah. Untuk mengurangi kadar air, dilakukan proses hydro thermal dewatering (HTD). Dalam penelitian ini digunakan batubara peringkat rendah yang berasal dari daerah Bayung Lencir, Kab. Musi Banyuasin. Untuk mengetahui pengaruh suhu proses HTD terhadap karaktersitik CWM yang dihasilkan, maka proses HTD dilakukan pada suhu 270°C, 300°C dan 330°C. Hasil penelitian menunjukkan bahwa kadar air bawaan batubara turun dari 30,85% menjadi 5,95%, 4,46% dan 3,64% (adb) secara berurutan pada suhu proses 270°C, 300°C dan 330°C. Nilai kalor batubara meningkat dari 4.555 kkal/kg (adb) menjadi 6.331 kkal/kg, 6.539 kkal/kg dan 6.845 kkal/kg (adb) masing-amsing pada suhu proses 270°C, 300°C dan 330°C. CWM yang dibuat dengan menggunakan batubara tanpa melalui proses HTD, kandungan batubara dalam CWM maksimal 43,33% berat. Setelah proses HTD pada suhu 270°C, kandungan CWM maksimal 57,07% berat, pada suhu 300°C 61,28% berat dan pada suhu 330°C 63,61% berat dengan viskositas semu pada shear rate 1/100 detik yang hampir sama, yaitu antara 900-1.100 mPa.s
THE APPLICATION OF FAILURE METHOD PROBABILITY FOR ANALYZING IN PIT DUMP STABILITY AT WEST BLOCK ‘X’ PIT PT BERAU COAL - EAST KALIMANTAN
Get PDFWest Block 'X' pit is one of the coal mining locations operated by the Lati Mine Operation – PT Berau Coal. Administratively, the Lati Mine is located as part of Berau Regency – East Kalimantan. The study area is located at the north side of the concession, in a syncline fold structure zone. The disposal design in this area needs to special attention from slope stability aspect due it is located on the wing of a mega syncline with a certain slope and constituent of unconsolidated materials. The pit design needs to be stable. The purpose of this study is to determine the level of stability of the in-pit dump by analyzing the current in-pit dump stability based on the value of the safety factor (FS) and the probability of failure (PoF). The method used in this study is a probabilistic analysis of slope stability based on the Morgenstern-Price method to obtain the value of the safety factor and the probability of failure. The study results show that the slope is in the safe category (stable slope) in the range of PoF values 0 – 1%, marginal slope 1 – 12%, and unstable slope above 12%. Based on such as results, it is necessary to modify the slope geometry categorized as unstable to carry out mine operation safely underneath the toe of slope
GROWTH AND PRODUCTION OF TEA PLANT (Camellia sinensis (L.) O Kuntze) AFTER PRUNING WITH BIO-ORGANOMINERAL AMELIORANT
Get PDFTea plant (Camellia sinensis (L.) O Kuntze) is one of the important plantation commodities that has long been cultivated in Indonesia. Mineral based ameliorant fertilization is one of the important factors to produce high productivity and maintenance of healthy plants. Ameliorant bio-organomineral (BIOM) is a fertilizer that utilizes mineral resources, potential microbes, and organic matter. This study aimed to determine the effect of BIOM's ameliorant on plant health and tea productivity after pruning. The Randomized Block Design (RBD) was accomplished by 8 treatments and three replications (100% conventional fertilizer, 100% BIOM, 80% single fertilizer + 100% BIOM, 80% conventional fertilizer + 80% BIOM, 80% conventional fertilizer + 60% BIOM, 60% conventional fertilizer + 100% BIOM, 60% conventional fertilizer + 80% BIOM, and 60% conventional fertilizer + 60% BIOM). The results showed that there was a significant effect of the combination of conventional fertilizer and BIOM ameliorant on shoot production and pekoe percentage, but not significantly different in tipping production, pekoe shoot ratio and banji shoots. The combination of 60% conventional fertilizer and 60% BIOM showed the highest total production of 31.81 kg/plot. Shoot production in the BIOM treatment was 17.36% higher than that of the conventional fertilizer application. The application of BIOM ameliorant was able to improve the plant health after pruning on the GMB 7 clone
PEMANFAATAN Typha angustifolia DAN FUNGI MIKORIZA ARBUSKULAR UNTUK FITOREMEDIASI AIR ASAM TAMBANG
No full textAir asam tambang (AAT) adalah air berasal dari tambang atau batuan yang mengandung mineral sulfida yang tersingkap dan teroksidasi akibat dari kegiatan penambangan terbuka. Kandungan sulfat dan logam yang tinggi di dalam air asam tambang mengakibatkan kerusakan lingkungan sehingga diperlukan penanganan khusus. Fitoremediasi dapat digunakan untuk mengatasi permasalahan tersebut sehingga sesuai dengan baku mutu lingkungan air asam tambang. Tujuan penelitian ini ialah untuk mengetahui pengaruh dosis aplikasi fungi mikoriza arbuskular (FMA) terhadap pertumbuhan dan serapan logam tanaman akumulator Typha angustifolia pada air asam tambang. Penelitian ini menggunakan rancangan acak lengkap dengan 4 perlakuan yaitu mo (0 g FMA/ember), m1 (10 g FMA/ember), m2 (12 g FMA/ember), m3 (14 g FMA/ember) dan 4 ulangan, sehingga diperoleh 16 satuan percobaan. Pengamatan yang dilakukan meliputi tinggi tanaman, jumlah anakan, Fe-akar, Mn-akar, Fe-larut, Mn-larut, pH AAT dan hubungan antar peubah pengamatan. Dosis terbaik dalam meningkatkan pertumbuhan T. angustifolia adalah perlakuan m3 (14 g FMA/ember), sedangkan terhadap serapan Fe dan Mn, perlakuan m2 (12 g FMA/ember) dengan nilai indeks fitoremediasi (IFR) Mn dan Fe 98,94% dan 57,93% memenuhi standar baku mutu lingkungan