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STUDI TRANSFORMASI FASA SISTEM BESI KARBON DENGAN PENGAMATAN THERMAL DIFERENSIAL Sialagan, Pontas; Manaf, Azwar
Makara Journal of Science Vol. 6, No. 1
Publisher : UI Scholars Hub

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TINJAUAN TEKNOLOGI PROSES EKSTRAKSI BIJIH NIKEL LATERIT Fathan Bahfie; Azwar Manaf; Widi Astuti; Fajar Nurjaman; Ulin Herlina
Jurnal Teknologi Mineral dan Batubara Vol 17 No 3 (2021): Jurnal Teknologi Mineral dan Batubara Edisi September 2021
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/jtmb.Vol17.No3.2021.1156

Abstract

Bijih nikel laterit merupakan mineral yang mengandung senyawa oksida besi-nikel. Teknologi pengolahan nikel laterit secara umum ada 3 metode yaitu hidrometalurgi, pirometalurgi dan reduksi selektif. Hidrometalurgi merupakan metode yang menggunakan pelindian dan larutan seperti asam untuk mengekstraksi nikel laterit. Metode dengan pelindian asam yang bertekanan adalah metode yang paling optimal untuk mendapatkan nikel dengan grade dan recovery tertinggi. Akan tetapi metode ini memiliki dampak pencemaran lingkungan akibat hasil proses pelindian dan waktu yang lama. Metode yang kedua, yaitu pirometalurgi menggunakan temperatur tinggi sampai 1600°C sehingga membutuhkan banyak energi seperti proses blast furnace. Metode dengan rotary kiln-electric furnace merupakan metode optimal dalam pengembangan nikel laterit. Akan tetapi kekurangannya yaitu tanpa pemisahan pengotor, energi yang besar, serta masih ada permasalahan teknis seperti adanya material yang mengalami melt partial. Metode yang ketiga yaitu reduksi selektif merupakan proses pemisahan dengan menyeleksi terbentuknya besi oksida sehingga mendapatkan kadar nikel yang tinggi tanpa energi yang tinggi. Hal ini disebabkan adanya penambahan aditif untuk menghambat terbentuknya besi dan menurunkan temperatur reduksi. Metode ini sebagai alternatif pengolahan bijih nikel laterit jenis limonit dan saprolit menjadi konsentrat nikel dengan kadar nikel di atas 5 %.
Perolehan Tio2 Dari Iron Ore Mengandung Titanium Melalui Proses Reduksi Karbon Dan Pelarutan Asam Elda Rayhana; Azwar Manaf
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 2, No 02 (2012): October
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v2i02.1288

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REDUCTION AND LEACHING PROCESSES. Indonesia has a large source of iron ore which is quite tempting for the purposes of exploitation in form of raw materials as well as for the production of pig iron. However, not all sources of iron ore are proved useful since not only because the present of deposit is scattere dinamounts of less significant but also because it contains element of tin oxide compounds with iron like ilmenite or FeTiO3. However,ilmenite can actually be used as a source of titanium metal which is much more valuable than Fe it self. In order to recover the Ti from their respective compound it is required the release of strong bonds between the atoms in the compound. This paper reports the recovery of Ti oxide of ilmenite containing iron ore which was obtained through a combination of carbon reduction and acid leaching processes. Carbon reduction of iron ore was carried out through mechanical milling between iron ore and carbon with a ratio of 1:1. This was successively followed by a sintering at a temperature of 1000 oC employing a heating rate of 10 ° C/min for 0-3 hours. The reduction process has resulted in the formation of 27.83wt% TiO2. In order to improve the recovery level of TiO2, further reduction process was conducted through an HCl leaching. This successive stage produced fine powders in the form of deposits. Based on our quantitative analysis, the recovery of TiO2 increased to a level of 73.73%.
Pengaruh Substitusi Ion Mn dan Ion Co Serta Ion Ti pada Pembentukan Fasa dan Sifat Magnetik Barium Hexaferrite BaFe9(MnCo)1,5Ti1,5O19 Disintesis Melalui Rute Metallurgi Serbuk Priyono P; Eddy Siradj; Azwar Manaf
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 3, No 01 (2013): April
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v3i01.1310

Abstract

Barium ferrite with hexagonal molecular BaFe12O19 is well-known for its high performance permanent magnetic and good mechanical properties and attracted attention of researchers for a long time. The hexaferrite powders were produced according to a conventional ceramic process with powder metallurgy method. Moreover, the powders were analyzed by X-ray diffraction, to detect the presence of secondary phases. The magnetic properties of the sampleswere measured at room temperature using Permeagraph with a maximum applied field of 1.5 T. The calculation of the lattice parameter on conventional magnets (BaFe12O19) results a = b = 5,894 Å and c = 23,210 Å, while the substituted phase has a range value of a = b between 5,893 Å to 5,899 Å, and c lattice parameter value is in the range of 23,328 ˚A to 23,346 Å.With the partial substitution of Fe+3 ions by Mn+2 ions, ion Co+2 and Ti+4 ion magnetic properties decrease primarily on the magnetic coercivity from 125 kA / m (conventional) to ~ 5 kA /m in the substituted materials.
DAMPAK PENINGKATAN PANAS DAN JENIS REDUKTAN TERHADAP SAPROLIT: STUDI PENDAHULUAN Bahfie, Fathan; Manaf, Azwar; Astuti, Widi; Nurjaman, Fajar; Prasetyo, Erik; Susanti, Diah; Sipahutar, Wahyu Solafide
Indonesian Mining Journal Vol 27 No 1 (2024): Indonesian Mining Journal, April 2024
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol27.No1.2024.1533

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Indonesia significantly contributes to the global electric vehicle battery market due to its substantial medium- and low-grade nickel reserves. This study utilized saprolitic nickel ore from Halmahera, Maluku, Indonesia. However, the research on saprolite needs some improvements due to its complex mineral composition, which affected on the roasting process significantly. Therefore, a thorough understanding of the properties of laterite ores is critically important, particularly concerning laterite pre-reduction processes. The ore was finely sieved to a particle size of less than 100 mesh and then heated at temperatures of 250, 900, and 1150°C with the variation of reductant (anthracite and palm kernel charcoal). Extensive mineralogical analysis was conducted using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The analysis of saprolite showed that it contains about 1.82% nickel, 30.47% iron, 10-20% magnesium, 4.86% aluminum, and 8.1% silicon by weight. Its mineral composition is mainly 53.1% goethite, 38.3% lizardite, and 8.7% quartz. The study found that goethite in saprolite was transformed into hematite around 250°C. At 900°C, the forsterite was crystallized, and at 1150°C, the ferronickel was formed. The transformation of lizardite is important as it affected on nickel diffusion within the iron matrix, which impacted on the material's properties. A thermal upgrading method with reductants like anthracite and palm kernel charcoal was used at lower temperatures to enhance the properties of saprolite. These findings provided valuable insights into saprolite's mineralogical composition and behavior, potentially offering improvements in various industrial processes and applications.
DAMPAK PENINGKATAN PANAS DAN JENIS REDUKTAN TERHADAP SAPROLIT: STUDI PENDAHULUAN Bahfie, Fathan; Manaf, Azwar; Astuti, Widi; Nurjaman, Fajar; Prasetyo, Erik; Susanti, Diah; Sipahutar, Wahyu Solafide
Indonesian Mining Journal Vol 27 No 1 (2024): Indonesian Mining Journal, April 2024
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol27.No1.2024.1533

Abstract

Indonesia significantly contributes to the global electric vehicle battery market due to its substantial medium- and low-grade nickel reserves. This study utilized saprolitic nickel ore from Halmahera, Maluku, Indonesia. However, the research on saprolite needs some improvements due to its complex mineral composition, which affected on the roasting process significantly. Therefore, a thorough understanding of the properties of laterite ores is critically important, particularly concerning laterite pre-reduction processes. The ore was finely sieved to a particle size of less than 100 mesh and then heated at temperatures of 250, 900, and 1150°C with the variation of reductant (anthracite and palm kernel charcoal). Extensive mineralogical analysis was conducted using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The analysis of saprolite showed that it contains about 1.82% nickel, 30.47% iron, 10-20% magnesium, 4.86% aluminum, and 8.1% silicon by weight. Its mineral composition is mainly 53.1% goethite, 38.3% lizardite, and 8.7% quartz. The study found that goethite in saprolite was transformed into hematite around 250°C. At 900°C, the forsterite was crystallized, and at 1150°C, the ferronickel was formed. The transformation of lizardite is important as it affected on nickel diffusion within the iron matrix, which impacted on the material's properties. A thermal upgrading method with reductants like anthracite and palm kernel charcoal was used at lower temperatures to enhance the properties of saprolite. These findings provided valuable insights into saprolite's mineralogical composition and behavior, potentially offering improvements in various industrial processes and applications.
EFFECT OF ANNEALING CYCLES ON DEEP DRAWABILITY OF LOW CARBON TITANIUM ADDED STEEL Iskandar Muda; Azwar Manaf
Jurnal Sains Materi Indonesia Vol. 21 No. 2 (2020): Jurnal Sains dan Materi Indonesia
Publisher : BRIN Publishing (Penerbit BRIN)

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EFFECT OF ANNEALING CYCLES ON DEEP DRAWABILITY OF LOW CARBON TITANIUM ADDED STEEL. Maximum mechanical properties and deep drawability of low carbon titanium added steels was obtained after heat treatment with simulation batch annealing cycles in an industrial process. The effect of holding times and holding temperatures on deep drawability were studied using tensile test for measuring normal anisotropy (r-value) and strain hardening exponent (n-value). Scanning electron microscope were employed for observation of microstructure in steel sheets. X-ray diffraction with pole figure techniques were also used for measuring texture of annealing. Results showed that as the temperature was increased up to 900 oC, both r and n values increased gradually and peaked in the temperature of 850 oC. This results showed that formability of sheet materials increased until batch annealing temperature reach 850 oC as increasing the ratio of intensities {111} /{100}. The largest mean r value of almost 2.6 was obtained in slow heating at holding temperature of 850 oC with n value of 0.27.
Optimized Carbonization and Kinetic Analysis of Palm Kernel Shell Porous Carbon for Heavy Metal Adsorption Hafizah, Mas Ayu Elita; Manaf, Azwar; Valency, Tiara; Andreas, Andreas; Manawan, Maykel
Indonesian Journal of Chemistry Vol 25, No 3 (2025)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.100714

Abstract

This study explores the use of porous carbon derived from palm kernel shells to adsorb lead ions (Pb2+) from water. Porous carbon was produced by carbonizing palm kernel shells at different temperatures (400, 600, and 800 °C) and was evaluated for its effectiveness in a lead chloride (PbCl2) solution. The best adsorption rate, reducing Pb2+ concentration by 27.5%, was observed by carbonized material at 800 °C with a 3 h contact time. Kinetic analysis suggested that the process followed a pseudo-second-order model, indicating that chemical adsorption was the dominant mechanism. The adsorption data were best described by the Freundlich isotherm, implying multilayer adsorption on an uneven surface. These findings highlight the efficient and low-cost potential of palm kernel shell-based porous carbon for removing heavy metals from wastewater. Palm kernel shell-derived porous carbon has proven to be a sustainable, cost-effective, and practical solution for mitigating Pb2+ contamination, positioning it as a promising candidate for environmentally friendly water treatment applications.
ECO FRIENDLY CITRIC ACID-ASSISTED SOL-GEL SYNTHESIS OF HIGH-PURITY NANO SILICA FROM DIENG GEOTHERMAL SLAG: CHARACTERIZATION AND OPTIMIZATION METHOD Birawidha, David C; Manaf, Azwar; Astuti, Widi; Daulay, Amru; Haryono, Tri; Sari, Yuliana; Suprihatin, Suprihatin
Indonesian Physical Review Vol. 8 No. 2 (2025)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v8i2.486

Abstract

Geothermal slag is a by-product of the geothermal power generation process, but its added value is minimal. With a silica content of up to 70%, geothermal slag has potential as a secondary silicon source for battery silicon anode precursors. Usually, the synthesis of nano-silica was carried out through the sol-gel method, in which HCl is usually used as a modifier to regulate the physical and chemical properties of the material. But in this study chose citric acid for modifier agent because it is more environmentally friendly. The challenge of using citric acid is the formation of carbon-based salts that can cause silica blackening if not washed well. Therefore, optimization was done by adjusting the pH to produce high-purity nano-silica. The sol-gel process was carried out by adding 10% NaOH and 5N Citric Acid, with varying pH base conditions from 8 to 11. XRF analysis results showed the highest purity at pH 8. Impurities were still visible based on XRD data, and the formation of nanoparticles was confirmed through morphological analysis using FESEM and TEM where the average particle size formed is between 55 nm.
Co-Authors Adi Ganda Putra Agus Sukarto Agus Sukarto Ahmad Royani Akmal Johan Andreas Andreas Arie Fiandimas Arieko Abdillah Asep Yudi Hercuadi Asep Yudi Hercuadi, Asep Yudi Bahfie, Fathan Bambang Soegijono Birawidha, David C Budhy Kurniawan Cahaya, Adam Badra Daulay, Amru Dedi Dedi Diah Susanti Djoko HP Doansi Tarihoran Dwita Suastiyanti Eddy Siradj Edie Sasito, Edie Eko Sulistiyono, Eko Elda Rayhana Elfrida Ratnawati Elisabeth A. S. Elsa Krisanti Erfan Handoko Erik Prasetyo Fajar Nurjaman Fajar Nurjaman Fathan Bahfie firdiyono, F Handoko, Djati Hasan Fahad Idris Novianto Iskandar Muda Iskandar Muda Iskandar Muda Lingga Hermanto Mabe Siahaan Manawan, Maykel Manawan, Maykel Mas Ayu Elita Hafizah Maykel Manawan Mujamilah Mujamilah Mulyaningsih, Neng Nenden Musfirah Cahya Fajrah, Musfirah Cahya Nanang Sudrajat Nelson Saksono Nelson Saksono Novizal Novizal, Novizal Novrita Idayanti Nurul Taufiqu Rochman Nurul Taufiqu Rochman Pontas Sialagan Priyono K. Priyono P Priyono Priyono Rafael F Maniur Ridwan Ridwan Roekmijati Soemantojo Roekmijati Soemantojo, Roekmijati Roekmijati W. Roekmijati W. Soemantojo, Roekmijati W. Roekmijati Widaningroem Roekmijati Widaningroem, Roekmijati Roekmijati Widaningrum Roekmijati Widaningrum, Roekmijati Rudi Subagja Saptari, Sitti Ahmiatri Setijo Bismo Setijo Bismo Setyo Purwanto Setyo Purwanto Sialagan, Pontas Sipahutar, Wahyu Solafide Sri Mulyaningsih Sri Mulyaningsih Suprihatin Suprihatin Taufik A. Bonaedy Tito Prastyo Rahman Tito Prastyo Rahman, Tito Prastyo Tri Haryono Ulin Herlina Valency, Tiara Wakid Ali Muntoha Widi Astuti Widi Astuti Wisnu A. Adi Wisnu Ari Adi Wisnu Ari Adi Wisnu Ari Adi Yana Taryana Yuliana Sari Yuliusman Yuliusman Yuliusman Yuliusman Yuyu Wahyu