Beneficiation Study of Iron Ore from Pakke area of Bontocani Subdistrict, Bone Regency of South Sulawesi, Indonesia Using Roasting and Magnetic Separation Methods

This study aims to examine the characteristics and analyze the magnetic beneficiation process of iron ore from Pakke area of Bontocani subdistrict, Bone regency. Mineralogical analysis using Microscopic and XRD (X-Ray Diffraction) methods indicate that iron ore sample is composed of quartz (SiO2), calcite (CaCO3), goetite (FeO.OH), hematite (Fe2O3) and magnetite (Fe3O4). The results of chemical analysis by means of XRF (X-Ray Fluorescence) method showed that sample consists of 30.49% Fe2O3, 42.39% SiO2, 10.03% MnO and 1.19% As2O3. Each feed fraction was separated using a low-intensity drum magnetic separator.  The higherst Fe2O3 content of concentrate product was 54.21% and recovery of 75.31% which was achieved at the size fraction of (-180 + 150) μm. The addition of wood charcoal as reducing agent by 3% during roasting process at the temperature of 950oC for 90 minutes has led to increase the Fe2O3 content in concentrate product about 63.791% but recovery was slightly recerease to about 65.20%. It was shown that the size fraction of (-180 + 150) μm is better feed in this experiment

MINERALOGI, GEOKIMIA DAN SIFAT ???LEACHING??? PADA ENDAPAN LATERIT NIKEL SOROAKO, SULAWESI SELATAN, INDONESIA

Endapan laterit nikel Soroako yang terdapat di bagian tengah Pulau Sulawesi\ud merupakan sumber utama nikel dari Indonesia. Endapan ini telah ditambang dan\ud diolah dengan menggunakan teknik peleburan konvensional oleh PT. Vale\ud Indonesia menghasilkan Ni matte. Endapan laterit nikel Soroako terdiri dari dua\ud tipe berdasarkan tingkat serpentinisasi batuan asalnya yaitu: tipe barat dan tipe\ud timur. Bijih tipe barat berasal dari hasil pelapukan kimia batuan peridotit tak\ud terserpentinkan; sedangkan bijih tipe timur dibentuk oleh hasil pelapukan kimia\ud batuan ultramafik dengan tingkat serpentinisasi sedang hingga tinggi. Studi ini\ud melaporkan hasil analisis mineralogi dan geokimia endapan laterit nikel daerah\ud Soroako dengan tujuan untuk mengetahui hubungan antara batuan dasar peridotit\ud terutama peran tingkat serpentinisasinya terhadap perkembangan endapan laterit\ud nikel. Percobaan pelindian juga telah dilakukan dengan tujuan untuk mengetahui\ud pengaruh komposisi mineral bijih saprolit terhadap perilaku disolusi mineral dan\ud laju pelindian logam serta implikasinya terhadap pengolahan bijih Ni secara\ud hydrometalurgi.\ud Analisis petrologi dan geokimia menunjukkan bahwa batuan peridotit di daerah\ud Soroako merupakan bagian dari ofiolit dengan kandungan olivin tinggi yang kaya\ud nikel. Batuan ini merupakan protolit yang paling sesuai dalam membentukan bijih\ud nikel laterit kadar tinggi. Proses serpentinisasi menyebabkan hilangnya sebagian\ud unsur Ni yang berdampak pada penurunan kadar Ni pada batuan dasar blok Petea.\ud Tingginya kadar Ni pada bijih nikel laterit blok barat relatif terhadap kadar bijih\ud nikel blok Petea sebagai konsekuensi dari adanya perbedaan konsentrasi Ni pada\ud protolit.\ud Studi mineralogi mengindikasikan bahwa pelapukan kimia batuan peridotit\ud pada blok barat yang berkomposisikan mineral-mineral primer (olivin dan sedikit\ud piroksin serta spinel) mengakibatkan proses transformasi mineral-mineral tersebut\ud menjadi goetit, silika, smektit, serpentin, talk dan garnierit; sedangkan batuan\ud ultramafik pada blok Petea yang disusun oleh serpentin, piroksin, klorit, dan\ud magnetit mengalami perubahan menjadi serpentin residual, amfibol, maghemit,\ud dan klorit membentuk zona saprolit. Pelapukan lebih lanjut secara intensif\ud mengakibatkan mineral-mineral sekunder pada zona saprolit berubah menjadi\ud oksida besi terutama goetit membentuk zona limonit di bagian atas profil.\ud Analisis geokimia pada profil laterit di kedua blok menunjukkan suatu pola\ud laterit nikel yang khas, dimana MgO, SiO2 dan CaO berkurang secara tajam ke\ud arah atas profil; sedangkan FeO, Al2O3, TiO2 dan Cr mengalami peningkatan.\ud Perhitungan indeks pelapukan dan kesetimbangan massa menunjukkan bahwa Mg\ud dan Si mengalami pengurangan pada profil laterit selama proses pelapukan namun\ud Si terlindih lebih cepat pada zona saprolit blok barat dibanding blok Petea.\ud Pengkayaan Mn dan Co pada zona batas saprolit-limonit akibat perpindahan\ud secara vertikal dari zona atas dan terpresipitasi pada profil pelapukan.\ud Secara umum, karakteristik geokimia dan mineralogi menunjukkan bahwa\ud genesa bijih terutama dikendalikan oleh sifat-sifat batuan dasar dan iklim lokal.\ud Karakteristik profil laterit pada dua blok menunjukkan perbedaan sejarah pelapukan dimana laju pelapukan kimia dan tingkat amblesan pada profil blok\ud barat lebih ekstrim dibandingkan dengan profil laterit pada blok Petea.\ud Proses pengkayaan Ni pada blok barat terjadi melalui pembentukan filosilikat\ud sekunder yang disebut ???garnierit???, sedangkan ???reaksi pertukaran ion??? merupakan\ud mekanisme pengakyaan NI yang terjadi pada blok Petea dimana Ni menggantikan\ud Mg pada struktur kristal serpentin residu. Nikel terkayakan pada zona saprolit\ud dengan kadar hingga mencapai 4,2 % pada blok barat, lebih tinggi dari blok Petea\ud dengan konsentrasi Ni mencapai 2.4 %. Nikel pada zona saprolit blok barat\ud menunjukkan pengkayaan absolut hingga 467 %, yang juga lebih tinggi dibanding\ud dengan pengkayaan pada zona saprolit blok Petea yaitu 459 %.\ud Mineral-mineral pembawa Ni pada bijih laterit blok barat terutama terdiri dari\ud ???garnierit, goethit dan sedikit talk; sementara serpentin residual merupakan\ud mineral utama pembawa Ni pada bijih blok Petea. Garnirierit pada blok barat\ud diidentifikasi sebagai campuran fasa antara seri mineral-mineral kerolit-pimelit,\ud lizardit-nepouit, talk-wilemsit dan Ni-smektit; sedangkan sepiolit-falcondoit\ud dengan sedikit kerolit-pimelit dan Ni-serpentin diidentifikasi sebagai seri mineral\ud penyusun garnierit pada blok Petea. Dengan demikian, endapan laterit Soroako\ud digolongkan sebagai tipe bijih silikat.\ud Percobaan pelindian dengan menggunakan asam sulfat pada tekanan atmosfir\ud terhadap dua contoh bijih saprolit dari masing-masing blok memperlihatkan\ud perilaku disolusi mineral yang berbeda. Olivin pada bijih saprolit blok barat\ud terdisolusi secara sempurna diikuti oleh serpentin dan goetit; sedangkan talk\ud sangat sulit terdisolusi, namun kuarsa tidak larut sama sekali. Sementara itu,\ud serpentin residual pada bijih saprolit blok Petea mudah mengalami disolusi diikuti\ud oleh klorit dan maghemit. Akan tetapi enstatit, amphibol dan kuarsa tidak\ud mengalami pelarutan. Laju pelindian Ni pada bijih saprolit blok barat lebih rendah\ud dibandingkan dengan bijih saprolit pada blok Petea. Perbedaan tingkat disolusi\ud mineral dan laju pelindian Ni dari kedua bijih ini mungkin disebabkan oleh\ud variasi struktur kristal dan tingkat substitusi logam baik pada mineral silikat\ud ataupun mineral oksida.\ud Dalam kaitannya dengan proses hydrometalurgi, diprediksikan bahwa koekstraksi\ud Ni dengan Mg dan Fe tidak dikehendaki karena akan mengkonsumsi\ud asam berlebih. Kehadiran mineral talk pada garnierit blok barat dapat\ud menyebabkan penurunan laju pelindian Ni akibat sifat refraktori dari mineral ini.\ud Di lain pihak, tingginya tingkat disolusi serpentin residual saprolit blok Petea\ud tidak hanya menyebabkan tingginya Ni terlarut akan tetapi juga dapat\ud menghasilkan magnesium terlarut dan silika amorf sebagai padatan sisa.\ud Kehadiran silika amorf dapat menghambat proses pemisahan logam lebih lanjut\ud dari larutan terlindih. Namun demikian, silika amorf dapat memiliki potensi\ud sebagai bahan baku untuk pabrikasi silikon karbida. Secara umum, ekstraksi Ni\ud dari kedua bijih saprolit masih rendah, akan tetapi bijih saprolit dari blok Petea\ud dapat memberikan potensi ekstraksi Ni yang lebih baik pada proses dengan\ud tekanan normal. Secara alternatif, bijih saprolit Petea dapat digunakan sebagai\ud umpan pada proses pelindian tahap kedua untuk netralisasi larutan terlindih dari\ud proses ekstraksi Ni dengan proses pelindian asam bertekanan tingg

Characterization of Some Coal Deposits Quality by Use of Proximate and Sulfur Analysis in the Southern Arm Sulawesi, Indonesia

This paper describes the characteristics of some coal depoasits from Paluda, Padanglampe, Lamuru and Tondongkura (South Sulawesi, Indonesia). The investigation of selected coal deposits in South Sulawesi have been carried out with the aims at elucidation of the coal quality which represented by proximate and total sulfur analyses. Results show that the lower inherent moisture of Paluda coal might be affected by igneous intrusion. In general, the studied coal samples have high ash and sulfur content with the average of 29.01 wt.% and 3.74 wt.% respectively. It was shown that there is no specific trend of the vertical distribution both for ash and sulfur. In term of coal utilization, it is indicated that South Sulawesi coal has constraints and challenging due to the high ash and sulfur. It is therefore suggested to reduce ash and sulfur content as much as possible if the coal is used as direct solid fuel in power plant or  industry

Study on mineralogy and chemistry of the saprolitic nickel ores from Soroako, Sulawesi, Indonesia: Implication for the lateritic ore processing

An investigation of mineralogy and chemistry of saprolitic nickel ores developed on ultramafic rock with different serpentinization degree from Soroako, Sulawesi has been conducted using X ray diffraction, thermal analysis, FTIR, and ICP-AES. The implication for the processing of these ores under acidic media was also studied. Weathering of unserpentinized peridotite in the Soroako west block produces saprolitic ore containing minerals such as relict olivine, goethite, quartz, talc with minor serpentine and smectite; whereas the weathered materials overlaying serpentinized peridotite in the Petea area are mainly composed of residual serpentine with lesser chlorite, maghemite, and remnant pyroxene and amphibole. Chemical analysis determined by ICP-AES demonstrates that west ore is higher in Si, Mg, and Ni, as compared to that Petea ore. Conversely, Fe and Al concentrations are higher in Petea ore than in west block ore. SEM-EDX examination reveals that olivine, talc, serpentine and goethite are the Ni-bearing phases occurring in west block ore; while serpentine is the principal host for Ni in the Petea ore. Chemical leaching under sulfuric acid reveals that olivine has highest dissolution rate in the west ore followed by serpentine; while talc, pyroxene, and iron oxides have slow dissolution rates. In contrast, serpentine in Petea ore is easily dissolved and is followed by chlorite; whereas amphibole, pyroxene, and maghemite are difficult to leach. Quartz is present in both ores and it seems to be undissolved during the chemical leaching. It is shown that Ni recovery from Petea saprolitic ore is higher than that of West Block ore

Low-Sulfidation Epithermal Carbonate-Base metal-Gold Mineralization Hosted by Tertiary Sedimentary Rocks in Bastem Prospect, Luwu District, Sulawesi Island, Indonesia: A Preliminary Study

In Indonesia, gold is typically mined out from epithermal, porphyry and skarn deposit types occurred within volcanic belts along magmatic arc or active continental margin setting. Numerous gold prospects, however, are recently discovered in association with metamorphic and sedimentary rocks. This paper is aimed to discuss a preliminary study on the occurrences and characteristics of the sedimentary rock-hosted low-sulfidation (LS) epithermal gold mineralization in Bastem (Bessengan Tempe) prospect, Luwu district, Sulawesi Island, Indonesia. Detailed geological and hydrothermal alteration mapping was performed to understand the distribution and characteristics of ore mineralization. Representative ore samples taken were analysed for ore chemistry by means of Fire Assay – Atomic Absorption Spectrometry (FA-AAS) and Acid Geochemical Digest - Atomic Absorption Spectrometry (GA-AAS). The results from this work that the Bastem prospect is stratigrapically occupied by Tertiary sedimentary rocks of Toraja formation, which is adjacent to volcanic rocks of Lamasi formation. Gold-bearing quartz±carbonate veins are hosted by mudstone and siltstone of Toraja formation. The quartz-carbonate veins show a typical LS epithermal open space filling texture containing erratic gold grade of up to 7.16 g/t with relatively high besemetals (Pb and Zn) grades of up to >0.4 and >1%, respectively. Based on those various features, the LS epithermal deposit is categorized as “carbonate-basemetal-gold mineralization type”, which might be originated in back arc rift/basin setting. This ‘unconventional’ sedimentary rock hosted-gold mineralization type would be the new target of gold exploration in Indonesia

Geochemical Characterization and Its Implication for Beneficiation of Coal from Tondongkura Village, Pangkep Regency South Sulawesi Province

Coal from Tondongkura, Pangkep Regency, South Sulawesi Province recently was used only as fuel in some industries, although it has high ash and sulfur content. This study is conducted to determine coal quality using proximate, mineral matter and geochemical inorganic matters analysis, as well as to recommended proper method of beneficiation of Tondongkura coal, so it can be used in various industries. Analysis result showed that seam 1 of Tondongkura coal can be classified into medium ash and middle sulfur coal. Meanwhile seam 2 of Tondongkura coal can be classified into high ash and high sulfur coal. Major elements were moderately high such as SiO2, Al2O3, Fe2O3 and CaO. Major element Fe2O3, and CaO had negative correlation with ash content of Tondongkura coal, while SiO2 and Al2O3 had positive correlation. Trace elements that need to be considered are the trace element which cause negative effect to health namely As, Cr, Mo and Pb. Lead (Pb) is inversely with coal ash from both seams and it is interpreted to be associated with organic matter, while As, Cr and Mo had various distribution for each seam of Tondongkura coal. Rare earth element in Tondongkura coal can be classified as Medium REY type, because Eu, Gd and Dy had high enrichment than the other REY. Pyrite contained in Tondongkura coal was syngenetic pyrite. Pyrite removal from coal can be done by using flotation method, because this method was combine physical and chemical method to separate pyrite mineral from coal. This method can decrease sulfur and ash content before the Tondongkura coal is used in various industry

Desulfurisasi Dan Deashing Pada Batubara Menggunakan NaOH Dan HCL Sebagai Leaching Agent

Penelitian mengenai desulfurisasi dan deashing pada batubara, selain untuk meningkatkan kualitas batubara juga merupakan usaha untuk mengurangi unsur-unsur yang menjadi penyebab terjadinya pencemaran lingkungan. Sampel batubara pada penelitian ini berasal dari batubara Desa Tondongkura, Kecamatan Tondong Tallasa, Kabupaten Pangkep, Provinsi Sulawesi Selatan. Desulfurisasi dan deashing batubara Tondongkura pada penelitian ini dilakukan dengan menggunakan NaOH dan HCl sebagai leaching agent. Untuk mengetahui pengaruh dari beberapa faktor dalam proses leaching, maka percobaan dilakukan dalam beberapa variabel, yaitu waktu, suhu, ukuran partikel, konsentrasi larutan NaOH, dan konsentrasi HCl. Hasil percobaan menunjukkan kadar total sulfur awal dari 3,67% turun hingga 2,93%, atau persentase penurunan maksimum total sulfur sebesar 20,03%, sedangkan persentase maksimum penurunan kadar abu sebesar 12,29%, atau dari kadar abu awal 27,44% turun hingga 24,06%. HCl digunakan sebagai leaching agent pada leaching tahap kedua pada batubara yang sebelumnya dileaching menggunakan larutan NaOH pada kondisi optimum. Dari hasil percobaan didapatkan maksimum persentase penurunan total sulfur sebesar 42,51%, yaitu dari total sulfur awal sebesar 3,67% diturunkan hingga 2,11% dan kadar abu sampel pada awalnya sebesar 27,44% diturunkan hingga 22,04%, atau persentase maksimum penurunan kadar abu sebesar 19,67%

Characteristics and Potential of Placer Gold Deposit in Lakan Bilem Block, West Kutai District, East Kalimantan, Indonesia

Kalimantan is recognized as one of Indonesian islands with huge prospect of minerals particularly gold both primary and secondary deposit styles. However, the publication of the gold resources is still restricted to be described in regional/district scale maps or exploration company internal reports, hence, a detailed study on deposit scale remains limited. This study is aimed to document the characteristics and the estimation of potential or resources of the secondary (placer) gold deposit in Lakan Bilem block, West Kutai district, East Kalimantan province, Indonesia. The study was done by field observation followed by microscopic analysis and simple resources estimation of the gold. Gold in the study area occur in the semi-consolidated paleo alluvial deposit as trace mineral. The gold morphologies show platy to angular form with coarse surface which indicates the process of gold deposition is predominantly controlled by hydrodynamic transportation at a relatively moderate regime. Estimation of the indicated resources of gold results a total of 4.96 tonnes of gold potentially occurred in the study area. Exploration drilling with 100 spacing grid is suggested to delineate lateral and vertical distribution of the gold deposit. The drilling also will upgrade confidence level of the resources from indicated to measured resources

Analisis Mineralogi Dan Kualitas Batubara Desa Kadingeh, Kecamatan Baraka, Kabupaten Enrekang, Sulawesi Selatan

Batubara Kadingeh di Kecematan Baraka, Kabupaten Enrekang, Provinsi Sulawesi Selatan secara geografis terletak pada titik koordinat: 03o28’31” Lintang Selatan dan 119o52’41” Bujur Timur dan termasuk dalam kategori rank batubara Subbituminous. Hal tersebut dibuktikan dengan beberapa hasil analisis yang telah dilakukan. Analisis mikroskopis menunjukkan bahwa terdapat dua mineral yang dominan seperti clay dan pirit. Sedangkan hasil analisis X-ray diffraction (XRD) batubara Desa Kadingeh menunjukkan kandungan mineral-mineral seperti kuarsa, goethit, illit dan pirit. Hasil analisis kualitas batubara menunjukkan bahwa kandungan inherent moisture berkisar dari 9,75%-11,17%, kandungan abu berkisar dari 3,54%-8,42%, volatile matter berkisar dari 25,26%-27,32%, fixed carbon berkisar dari 53,09%-61,45%, total sulfur berkisar dari 0,15%-0,21%, dan nilai kalori berkisar dari 5366,06 kcal/kg-6164,59% kcal/kg. Berdasarkan klasifikasi batubara menurut ASTM (1981), batubara Desa Kadingeh yang paling ekonomis digunakan pada industri yaitu SE-IIC dan SE-IIB tergolong batubara jenis Subbituminous A, sedangkan SE-IIA tergolong batubara Subbituminous B

Thermal and Infrared Studies of Garnierite From the Soroako Nickeliferous Laterite Deposit, Sulawesi, Indonesia

DOI: 10.17014/ijog.v7i2.137Mineralogical characterization of some garnierite samples from Soroako have been conducted using X-ray diffraction, thermal analysis, and infrared spectroscopy methods. XRD patterns reveal the samples mainly containing the mixture of kerolite (talc-like phase) and serpentine with minor smectite, sepiolite, and silica. Thermal analyses of garnierite samples indicated by DTA curves are in good agreement with patterns that have been reported in literature. Three endothermic peaks normally occur in the ranges between 58º C and <800º C illustrating three steps of weight losses: adsorbed, bound, and hydroxyl/crystal water. One additional weight loss in low temperature region of sepiolite is corresponding to the lost of zeolitic water. Infrared spectra appeared in 3800 - 3200 cm-1 region generally exhibit broad absorption bands, indicating low crystallinities of studied samples and can be assigned to the presence of hydroxyl group bonded to octahedral coordination mainly Mg atom. The bands observed at 1660 cm-1, 1639 cm-1, 1637 cm-1, and 1633 cm-1 in all samples indicate water molecules. FTIR spectra displaying the strong bands at 1045 cm-1, 1038 cm-1, and 1036 cm-1 could be related to the presence of Si-O-Si bonds linking to tetrahedral coordination. The strong absorption bands appeared at 511 cm-1, 505 cm-1, 499 cm-1, and 496 cm-1 in respective samples are attributed to divalent cation bonds (e.g. Mg, Ni-O). Both TG/DTA and FTIR seem to be the powerful tool in diagnosing the crystal chemistry of garnierite which is mainly composed of phyllosilicate minerals