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"Dewasa ini kebutuhan energi di dunia mengalami peningkatan yang sangat signifikan. Salah satu alternatif penghasil energi yang murah dan dapat bertahan lama adalah penggunaan energi surya. Bahan dasar yang digunakan untuk perangkat sel surya adalah semikonduktor, yaitu senyawa Cu2ZnSnS4. Tujuan dari penelitian ini adalah mendapatkan paduan Cu - Zn - Sn sebagai bahan dasar awal untuk pembuatan paduan sel surya. Peleburan paduan tersebut menggunakan Vacuum Arc Melting Furnace. Hasil pengamatan struktur mikro dan XRD menunjukkan adanya paduan Cu - Zn - Sn yang terbentuk. Hasil pengamatan EDX menunjukkan kandungan rata-rata yang ada pada setiap sampel sebesar 66.13% Cu, 8.65% Zn dan 25.22% Sn. Hasil pengujian kekerasan menunjukkan bahwa nilai kekerasan bergantung pada distribusi komposisi yang ada dan pertumbuhan butir pada saat pendinginan.

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The needs for energy in the world highly increase. Solar cell is the alternate energy which is cheap and has more durable. The basic compound of solar cell device is semiconductor, like Cu2ZnSnS4. The aim of this research is to get Cu ' Zn ' Sn alloy as basic material for solar cell Cu2ZnSnS4. Melting process use Vacuum Arc Melting Furnace. Cu ' Zn ' Sn alloy was observed by XRD and microstructure images.

EDX analysis results show the percentages of 66.13% Cu, 8.65% Zn and 25.22% Sn. From hardness testing shows that the point of hardness depend on composition distribution and grain growth at solidification."

"Sel surya merupakan alat yang berupa semikonduktor yang memiliki kemampuan untuk merubah cahaya matahari menjadi energi listrik. Paduan Cu2ZnSnS4 merupakan salah satunya. Penelitian ini bertujuan untuk membuat dan mengkarakterisasi paduan Cu-Zn-Sn dari logam kuningan (63,4/36,2) dan timah. Peleburan dilakukan dengan vacuum arc melting furnace. Pengujian EDS paduan menunjukkan adanya penurunan persentase Zn pada seluruh sampel. Pengujian XRD menunjukkan adanya paduan Cu2ZnSn yang terbentuk. Hasil uji kekerasan mengindikasikan semakin tinggi kandungan Sn yang melebihi batas kelarutannya maka semakin rendah nilai kekerasannya. Hasil foto mikro menunjukkan struktur yang berbentuk dendritik, homogen dan merata di seluruh bagian.

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Solar cell is a semiconductor device that has the ability to transform sunlight into electrical energy. Cu2ZnSnS4 alloy is one of them. The aims of this research are to create and characterize the Cu-Zn-Sn alloy from brass (63.4/36.2) and tin. The alloying process is done by vacuum arc melting furnace. EDS test results showed a reduction in the percentage of Zn in all samples. XRD test showed that Cu2ZnSn alloy is formed. Hardness test results indicate that alloy with higher Sn percentage that exceed it's solubility limit will have lower hardness. The alloy microstructure showed dendritic-shaped structures, homogeneous and evenly distributed throughout the section."

"Semikonduktor yang digunakan sebagai lapisan penyerap pada sel fotovoltaik tersusun atas beberapa unsur yang membentuk suatu paduan, salah satunya adalah Cu2ZnSnS4. Tujuan dari penelitian ini adalah untuk mengetahui karakteristik paduan Cu-Zn-Sn dengan melakukan peleburan antara kuningan (70/30) dan timah. Peleburan dilakukan dengan metode arc melting furnace. Hasil dari pengamatan struktur mikro dan analisis EDX menunjukkan terbentuknya paduan Cu-Zn-Sn dengan kadar sekitar 50%Cu-25%Zn-25%Sn. Hasil analisis XRD menunjukkan terbentuknya paduan Cu2ZnSn. Dari hasil uji kekerasan didapat bahwa semakin tinggi kandungan Cu di dalam paduan maka nilai kekerasan akan semakin meningkat.

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Semiconductor that use for absorber layer in photovoltaic cell contain many elements to form some alloy, one of them is Cu2ZnSnS4. The aim of this reserch is to characterization of Cu-Zn-Sn alloy with remelting between brass (70/30) and tin. Remelting process is done by arc melting furnace.

Microsrtucture observe and EDX analysis results a Cu-Zn-Sn alloy with approximately containing 50%Cu-25%Zn-25%Sn. XRD analysis show that this process form a Cu2ZnSn alloy. From hardness testing, alloy with higher Cu contents have higher hardness."

"Tingkat konsumsi energi yang semakin besar, mendorong manusia untuk menciptakan suatu energi alternatif yang dapat diperbaharui dan murah, salah satu adalah sel surya. Namun, sel surya yang ada sekarang begitu mahal apabila dibandingkan dengan energi fosil. Oleh karena itu, kedepannya akan dibuat sel surya jenis lapis tipis karena terdapat reduksi terhadap berat sel surya selain efisiensi dan harga yang bersaing. Pada penelitian ini telah dibuat paduan Cu-Zn-Sn (CZT) dengan metode arc melting furnace yang akan digunakan sebagai material target pada penumbuhan lapisan tipis Cu2ZnSnS4 (CZTS) untuk bahan dasar sel fotovoltaik. Pada proses pemaduan didapatkan hasil yang memuaskan, dimana dihasilkan ingot berbentuk solid dan tidak menempel pada krusibel. Pada karakterisasi yang dilakukan dengan menggunakan EDS, XRD dan mikroskop optik terhadap ingot paduan CZT menunjukkan hasil yang memuaskan, dimana dari hasil proses pemaduan telah didapatkan paduan CZT yang homogen dengan membentuk paduan 2Cu/Zn/Sn. Ingot hasil paduan CZT ini dapat digunakan dalam penumbuhan lapisan tipis Cu2ZnSnS4.

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The rate of energy consumption that has been increased, leads human to search for an alternative of energy that is renewable and cheap solar cell. However, until recently solar cell is considered too expensive compared to fossil based energy. Such as a thin film solar cell can be employed to reduce weight and improved efficiency with comparable price. In this research, a Cu-Zn-Sn (CZT) has been succesfully made with arc melting furnace method that can be applied for target materials on the growing of Cu2ZnSnS4 (CZTS) thin film for basic material of photovoltaic cell.Successfully solid CZT ingot was produced without adhering to the crucible. On characterization utilizing EDS, XRD, and optical microscope, it showed that the alloying process of CZT resulting in a Cu2ZnSn homogeneous alloy. This resulting ingot alloy is likely usable for CZTS thin film growing process."

"[ABSTRAKLogam ferromangan adalah salah satu unsur paduan penting pada bajauntuk meningkatkan sifat mekanis, ketahanan aus, dan kekerasannya. Bentukferromangan (FeMn) telah diatur dalam standard ASTM dengan kadar minimalsebesar 75% Mangan (Mn). Tujuan penelitian ini adalah pembuatan logam FeMndengan kandungan minimal 60%Mn dari bijih mangan lokal dan mempelajari efekdari basasitas terak yang dipengaruhi oleh penambahan kapur sebagai zat aditifdalam proses pembuatan ferromangan terhadap jumlah produk ferromangan yangdihasilkan dan konsumsi energi yang dibutuhkan dalam proses tersebut.Dalam penelitian ini digunakan bijih mangan lokal kadar menengah daridaerah Jember-Jawa Timur 39.38 Mn ? 2.89 Fe ? 26.58 SiO2 (Medium Grade Ore)dengan teknologi Mini Sub-merged Arc Furnace (SAF) di UPT BPM LIPI,Lampung. Setiap satu kali proses, digunakan 30 kg bijih mangan (Ø ±30mm), 7.5kg kokas, dan jumlah batu kapur yang bervariasi, yaitu; 8, 10, 12, dan 14 kg.Proses peleburan berlangsung pada temperatur 1200-1500 oC. Kemudian hasilakan dianalisa dengan menggunakan XRF (X-Ray Fluoroscence), XRD (X-RayDiffraction), AAS (Atomic Absorbtion Spectrometry), dan Proksimat.Hasil penelitian menunjukan bahwa dengan meningkatnya basasitas terak(dari 0.32 hingga 0.76) akan meningkatkan jumlah produk ferromangan hingga 8.2kg FeMn, kemudian memaksimalkan kadar % mangan yang tereduksi pada logamhingga mencapai komposisi kimia yang optimal (78,13 Mn-12,65 Fe-8.93 Si),menekan konsumsi energi hingga 9.8 kwh/kg ferromangan, menekan angkakonsumsi elektroda, dan menghasilkan prosentase efisiensi proses berupa % yieldyang cukup tinggi yakni sebesar 58.61%. Hasil lain yang menunjang prosespengolahan ferromangan dengan meningkatnya hasil basasitas terak adalahtercapainya suhu reaksi yang tinggi yakni sebesar 15940C sehingga membuatreduksi oksida mangan pada terak menjadi mangan pada logam semakin baik,kemudian jumlah terak juga dapat ditekan. Selanjutnya secara tinjauan aspekekonomi dari keempat kali proses penelitian, maka didapatkan hasil yang palingmenguntungkan sebesar Rp 5.731,-/proses.ABSTRACTFerromanganese metal is an important alloying element in steel productionindustry used to maximize its mechanical properties such as wear resistance andhardness. The most common form of ferromanganese according to ASTM standardcontain min.75%Mn and max.25%Fe inside the product. The target of this researchis to obtain ferromanganese metal with min.60%Mn using medium grademanganese ore (39.38 Mn ? 2.89 Fe ? 26.58 SiO2) from Jember district - East Java,yet the effect of its slag basicity will also support the most optimum result. This kindof basicity will determined by the amount of limestone as fluxing agent which addedto the furnace. Moreover, this study will focus to the effect of its slag basicity on thenumber of ferromanganese product and the amoung of energy consumption.This study was taking place at UPT BPM LIPI Lampung, Sumatera. Usingtheir Mini Sub-merged Arc Furnace (SAF) the process began without anybeneficiation processs for its raw material. Manganese ore Ø ±30mm, cokes, andlimestones were added at the same time to the SAF and melted at 1200-1450 oC.Processes were repeated 4 times with each process using 30 kg manganese ore, 7.5kg cokes, and limestones which varied from 8, 10, 12, and 14 kg. Validity of thisstudy supported by the chemical analysis which took place before and afterreduction process using some tools such as XRF (X-Ray Fluoroscence), XRD (XRayDiffraction), AAS (Atomic Absorbtion Spectrometry), and Proxymate analysis.The result of this research showed an increasing trend in product?s qualityas the slag basicity and the amount of limestone increased. As the slag basicityincrease, the number of ferromanganese metal products were also increased until8.2 kg FeMn and the amount of manganese element in metal phase also showed themost optimum chemical composition of ferromanganese metal (78,13 Mn-12,65 Fe-8.93 Si). Furthermore, the energy consumption can be reduced until 9.8kwh/kg FeMn as well as the electrodes consumption and also the efficiencypercentage or % yield process can be increased up to 58.61%. Other parameterswhich used to support these 4-times-research plan was the temperature level whichturned out to be as high as 15940C and helped the reduction process of manganeseoxide into manganese metal became easier. Not only to obtain more manganesecontent in metal phase, but also this level of reduction temperature can reduced theamount of slag. Finally, in addition to support the optimum data, economic analysisalso showed that this composition was the most profitable process with Rp 5.731,-/process as its profit., Ferromanganese metal is an important alloying element in steel productionindustry used to maximize its mechanical properties such as wear resistance andhardness. The most common form of ferromanganese according to ASTM standardcontain min.75%Mn and max.25%Fe inside the product. The target of this researchis to obtain ferromanganese metal with min.60%Mn using medium grademanganese ore (39.38 Mn – 2.89 Fe – 26.58 SiO2) from Jember district - East Java,yet the effect of its slag basicity will also support the most optimum result. This kindof basicity will determined by the amount of limestone as fluxing agent which addedto the furnace. Moreover, this study will focus to the effect of its slag basicity on thenumber of ferromanganese product and the amoung of energy consumption.This study was taking place at UPT BPM LIPI Lampung, Sumatera. Usingtheir Mini Sub-merged Arc Furnace (SAF) the process began without anybeneficiation processs for its raw material. Manganese ore Ø ±30mm, cokes, andlimestones were added at the same time to the SAF and melted at 1200-1450 oC.Processes were repeated 4 times with each process using 30 kg manganese ore, 7.5kg cokes, and limestones which varied from 8, 10, 12, and 14 kg. Validity of thisstudy supported by the chemical analysis which took place before and afterreduction process using some tools such as XRF (X-Ray Fluoroscence), XRD (XRayDiffraction), AAS (Atomic Absorbtion Spectrometry), and Proxymate analysis.The result of this research showed an increasing trend in product’s qualityas the slag basicity and the amount of limestone increased. As the slag basicityincrease, the number of ferromanganese metal products were also increased until8.2 kg FeMn and the amount of manganese element in metal phase also showed themost optimum chemical composition of ferromanganese metal (78,13 Mn-12,65 Fe-8.93 Si). Furthermore, the energy consumption can be reduced until 9.8kwh/kg FeMn as well as the electrodes consumption and also the efficiencypercentage or % yield process can be increased up to 58.61%. Other parameterswhich used to support these 4-times-research plan was the temperature level whichturned out to be as high as 15940C and helped the reduction process of manganeseoxide into manganese metal became easier. Not only to obtain more manganesecontent in metal phase, but also this level of reduction temperature can reduced theamount of slag. Finally, in addition to support the optimum data, economic analysisalso showed that this composition was the most profitable process with Rp 5.731,-/process as its profit.]"

"[ABSTRAKPotensi cadangan bijih mangan di Indonesia cukup besar, namun terdapatdi berbagai lokasi yang tersebar di seluruh Indonesia. Komoditi ini menjadi bahanbaku yang tidak tergantikan di industri baja dunia. Ferromangan (FeMn)merupakan logam paduan dengan komposisi 75% Mangan (Mn) dan 25% besi (Fe)yang umumnya digunakan pada proses peleburan besi/baja guna memperbaikisifak-sifat mekanik dari produk yang dihasilkan.Penelitian ini dilakukan untuk mempelajari pengaruh proses pencanpuranbijih Mn kadar rendah (LG) yang berasal dari Kab. Tanggamus, Lampung (16,3%Mn-19,2 %Fe-20,2 %Si) dengan bijih Mn kadar menengah (MG) yang berasaldari Jember, Jawa Timur (27,7 %Mn-4,4 %Fe-14,7%Si) sebagai bahan baku untukpembuatan logam FeMn dengan kandungan minimal sebesar 50 %Mn. Penelitianini dilakukan sebanyak 5 kali percobaan dengan variasi pada campuran bijih Mnyaitu [1] 25 %LG+75 %MG, [2] 50 %LG+50 %MG, [3] 75 %LG+25 %MG, [4]100 %LG, dan [5] 100 %MG. Bijih mangan diproses menggunakan Submerged ArcFurnace (SAF) dengan input berupa bijih Mn sebagai bahan baku utama, kokassebagai reduktor, dan kapur sebagai aditif. Ketiga bahan baku tersebut dileburhingga mencapai temperatur 1500 oC. Untuk mengetahui kualitas bahan baku danproduk FeMn yang dihasilkan, dilakukan analisa seperti XRF (X-RayFluoroscence), XRD (X-Ray Diffraction), AAS (Atomic Absorbtion Spectrometry),dan Proksimat.Dari hasil penelitian didapatkan bahwa untuk percobaan [1] diperolehlogam FeMn sebanyak 5,2 Kg dengan kadar 54,05 %Mn, percobaan [2] diperolehlogam FeMn sebanyak 4,75 Kg dengan kadar 50,03 %Mn, percobaan [3] diperolehlogam FeMn sebanyak 4,6 Kg dengan kadar 36,44 %Mn, percobaan [4] diperolehlogam FeMn sebanyak 4,3 Kg dengan kadar 31,13 %Mn, dan percobaan [5]diperoleh logam FeMn sebanyak 12,8 Kg dengan kadar 75,19 %Mn. Pengaruh dariproses pencampuran (Mn-blend) dalam pembuatan ferromangan ini adalahsemakin banyak komposisi bijih Mn kadar menengah (MG) yang digunakan,menyebabkan (a) semakin banyaknya kokas dan semakin berkurangnya kapur yangdibutuhkan, (b) meningkatnya yield, jumlah produk, serta kandungan persentaseMn dari FeMn yang dihasilkan, dan (c) semakin rendahnya konsumsi energi yangdibutuhkan.ABSTRACTThe potential reserve of manganese ore in Indonesia is very large, but itwas located in different locations spread throughout Indonesia. Manganese ore isone of raw material in producing ferromanganese that is not replaceable in theworld steel industry. Ferromanganese (FeMn) is an alloying metal that containedof 75% Manganese (Mn) and 25% Iron (Fe) which is generally used in the processof iron/steel making to improve its mechanical properties.In this experiment, ferromanganese production was conducted by blendingtwo kinds of manganese ore, that was low grade Mn ore (LG) which derived fromTanggamus, Lampung (16,3 %Mn-19,2 %Fe-20,2 %Si) and medium grade Mn ore(MG) which derived from Jember, East Java (27,7 %Mn-4,4 %Fe-14,7 %Si), toobtain ferromanganese with a minimum content of 50 %Mn. The composition ofMn-blend in this experiment was [1] 25 %LG+75 %MG, [2] 50 %LG+50 %MG,[3] 75 %LG+25 %MG, [4] 100 %LG, and [5] 100 %MG. This mixed manganeseore was processed by using Submerged Arc Furnace (SAF). Cokes and limestonewas added into the furnace as reductant and flux agent, respectively. Those rawmaterials are smelted until 1500 °C. To determine the composition of raw materialsand the product of FeMn, analysis such as XRF (X-Ray Fluorescence), XRD (XRayDiffraction), AAS (Atomic Absorption Spectrometry), and proximate have to bedone.From each composition of Mn-blend above in this experiment, it wasobtained that [1] 5,2 Kg of FeMn with 54,05 %Mn, [2] 4,75 Kg of FeMn with 50,03%Mn, [3] 4,6 Kg of FeMn with 36,44 %Mn, [4] 4,3 Kg of FeMn with 31,13 %Mn,and [5] 12,8 Kg of FeMn with 75,19 %Mn. The effect of Mn-blend in thisferromanganese production was by the increasing composition of the mediumgrade manganese ore (MG) that will cause: (a) the increasing number of cokes andthe decreasing of limestone required, (b) the increasing of yield, the number ofproducts, and also the percentage of manganese content FeMn, and (c) thedecreasing of energy consumption required., The potential reserve of manganese ore in Indonesia is very large, but itwas located in different locations spread throughout Indonesia. Manganese ore isone of raw material in producing ferromanganese that is not replaceable in theworld steel industry. Ferromanganese (FeMn) is an alloying metal that containedof 75% Manganese (Mn) and 25% Iron (Fe) which is generally used in the processof iron/steel making to improve its mechanical properties.In this experiment, ferromanganese production was conducted by blendingtwo kinds of manganese ore, that was low grade Mn ore (LG) which derived fromTanggamus, Lampung (16,3 %Mn-19,2 %Fe-20,2 %Si) and medium grade Mn ore(MG) which derived from Jember, East Java (27,7 %Mn-4,4 %Fe-14,7 %Si), toobtain ferromanganese with a minimum content of 50 %Mn. The composition ofMn-blend in this experiment was [1] 25 %LG+75 %MG, [2] 50 %LG+50 %MG,[3] 75 %LG+25 %MG, [4] 100 %LG, and [5] 100 %MG. This mixed manganeseore was processed by using Submerged Arc Furnace (SAF). Cokes and limestonewas added into the furnace as reductant and flux agent, respectively. Those rawmaterials are smelted until 1500 °C. To determine the composition of raw materialsand the product of FeMn, analysis such as XRF (X-Ray Fluorescence), XRD (XRayDiffraction), AAS (Atomic Absorption Spectrometry), and proximate have to bedone.From each composition of Mn-blend above in this experiment, it wasobtained that [1] 5,2 Kg of FeMn with 54,05 %Mn, [2] 4,75 Kg of FeMn with 50,03%Mn, [3] 4,6 Kg of FeMn with 36,44 %Mn, [4] 4,3 Kg of FeMn with 31,13 %Mn,and [5] 12,8 Kg of FeMn with 75,19 %Mn. The effect of Mn-blend in thisferromanganese production was by the increasing composition of the mediumgrade manganese ore (MG) that will cause: (a) the increasing number of cokes andthe decreasing of limestone required, (b) the increasing of yield, the number ofproducts, and also the percentage of manganese content FeMn, and (c) thedecreasing of energy consumption required.]"

"Phase trnasformation temperature of shape memory alloy - Tini produced by arc - melting technique. The observation of phase trnasformation temperature of Tini alloys produced by arc - melting technique was carried out by alloying Ti - 53%w Ni. Tini alloys were tempered at 900oC and then followed by quenching at 20oC and 5oC and finally were aged at 400oC for 1,4 and 16 hours. The Ti-53%. Ni alloyed is applied to obtain as shape memory alloys base on Tini . The Tini sample was analyzed by optical microscope, X - ray diffraction and simultaneous symmetrical thermoanalyzer (STA) . The result show that the martensitic phase has a structure of BCT (bODY CENTER TETRAGONAL) formed at room temperarure. The phase transformation temperature from martensitic - austensitic phase was taken place at (162+5)oC"

"Ferokrom 45-75 Cr dan 35-50 Fe paduan penting pembuatan baja tahan karat karena sifat kekuatan dan ketahanan korosi yang tinggi. Ferokrom berasal dari endapan kromit di wilayah Indonesia adanya berkadar rendah dengan ratio Cr/Fe < 1.5 sehingga diperlukan benefisiasi. Tahapan benefisiasinya pemisahan magnetik lemah dilanyutkan pemanggangan temperatur, waktu, jenis reduktor dan berat CaCO3 , hasil pemanggangan dilakukan pemisahan magnetik kuat dan diuji xrf dan xrd. Parameter optimal benefisiasi untuk pembuatan briket input peleburan tanur SAF. Peleburan briket kromit diteliti pengaruh basisitas terhadap parameter ratio Cr/Fe, kadar kromium dan besi, konsumsi energi/berat produk . Pengaruh temperatur pemanggangan 800, 1000 dan 1200 oC terhadap ratio Cr/Fe optimum temperaturnya 1000 oC ratio Cr/Fe sebesar 1,53. Pengaruh waktu pemanggangan 30, 60 dan 90 menit terhadap ratio Cr/Fe optimum waktunya 60 menit ratio Cr/Fe sebesar 1,53. Pengaruh reduktor grafit, kokas dan arang batok terhadap ratio Cr/Fe optimum redukror arang batok ratio Cr/Fe sebesar 1,60. Pengaruh wt CaCO3 5 , 10 dan 20 terhadap ratio Cr/Fe optimum wt CaCO3 pada 20 rasio Cr/Fe sebesar 1,60. Basisitas terak = 2 memberikan ratio Cr/Fe optimum =1,06 , kadar Cr = 50,07 . Konsumsi energi/berat logam optimum 5,7 Kwh/Kg pada nilai basisitas 1,2.

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Ferrochrome is an important alloy of stainless steel due to its high strength and corrosion resistance. Ferromchrome is derived chromite in the Indonesia region low grade Cr Fe "

"Cadangan bijih mangan kadar rendah di Indonesia cukup besar, namun cadangan bijih mangan tersebut tidak dapat dimanfaatkan secara optimal karena rendahnya rasio Mn/Fe.Sehingga diperlukan penelitian untuk mempelajari metode benefiasi guna meningkatkan rasio Mn/Fe, menggunakan bijih mangan kadar rendah dari Kabupaten Tanggamus (MnO=15.30%, rasio=0.91) dan kabupaten Jember (MnO=28.66%, rasio=1.39) supaya bisa dijadikan bahan baku dalam pembuatan FeMn menggunakan SAF.Penelitian benefisiasi bijih mangan kadar rendah dimulai dengan melakukan fraksinasi untuk mendapatkan ukuran butir 841-420 μm, 420-250 μm dan 250-177 μm kemudian dilakukan proses pemisahan gravitasi untuk menghasilkan concentrate dan tailing yang akan digunakan sebagai bahan baku untuk reduction reduction roasting. Proses reduction roasting dilakukan dengan variasti suhu 500°C, 700°C dan 900°C serta variasi waktu reduction roasting 30, 60, 90 dan 120 menit dan kemudian dilakukan proses pemisahan secara magnetic. Material non magnetik yang menghasilkan peningkatan rasio Mn/Fe paling optimum akan dilakukan proses briketisasi untuk digunakan sebagai bahan baku pembuatan FeMn menggunakan SAF.Pengaruh variasi temperatur dan waktu reduction roasting memberikan hasil rasio Mn/Fe optimum 6.11, pada partikel non magnetik ukuran 841-420 μm dengan suhu reduction roasting 700°C selama 60 menit. Proses reduction roasting juga menyebabkan munculnya fase baru seperti Hausmanite (Mn3O4), Manganosite (MnO), Fayalite (Fe2SiO4) dan Phlogopite (KMg3(AlSi3O10(OH)2), akibat proses perubahan fase pada bijih mangan. Fase mineral tersebut muncul pada reduction roasting variasi waktu 60 menit, 90 menit dan 120 menit, serta muncul pada variasi suhu 500°C, 700°C dan 900°C.Pada pengujian dalam SAF digunakan basisitas berdasarkan stoichiometri dengan nilai 1.17, 1.32, 1.15 dan basisitas referensi hasil penelitian Bobby et al, 2015, dengan nilai 0.7. Penggunaan basisitas 0.7 menghasilkan kenaikan berat metal dan menurunkan berat terak pada saat diproses dalam SAF. Selain itu basisitas stoichiometry hanya menghasilkan ferromangan dengan Mn=35.47% dan basisitas referensi 0.7 menghasilkan Ferromangan dengan Mn=60%.Hasil penelitian ini menunjukkan bahwa peningkatan rasio menggunakan benefisiasi bisa mencapai rasio 6.11. Sedangkan proses pembuatan FeMn dengan menggunakan bijih mangan kadar rendah pada submerged arc furnace bisa menghasilkan kadar Mn 60% dengan kontrol pada basisitas untuk mengurangi volume terak, meningkatkan berat logam dan menaikkan kadar Mn.

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Low grade manganese ore reserves in Indonesia is quite large, but manganese ore reserves can not be used optimally because of the low ratio of Mn / Fe.In that case, research is needed to study the methods of benefiasiation to increase the ratio of Mn / Fe, using low grade manganese ore from Tanggamus ( MnO = 15.30% ratio = 0.91) and Jember (MnO = 28.66%, ratio = 1.39) that can be used as raw material in the manufacture of FeMn using SAF.

Research for beneficiation of low grade manganese ore started by fractionation to obtain the grain size of 841-420 μm, 420-250 μm dan 250-177 μm then performed meja getar process to produce the concentrate and tailings to be used as ingredients raw for reduction roasting. Reduction roasting variety process carried out with a temperatur of 500 °C, 700 °C and 900 °C and roasting time variation of 30, 60, 90 and 120 minutes and then a magnetic separation process. Non-magnetic material that produces an increase in the most optimum ratio of Mn/Fe will be used into bricketing process as raw material for FeMn using SAF.

The effect of variation of temperatur and roasting time results ratio of Mn/Fe optimum 6.11, on a non-magnetic particle size of 841-420 μm with a roasting temperature of 700 °C for 60 minutes. Roasting also cause new phase occurensces such as Hausmanite (Mn3O4), Manganosite (MnO), Fayalite (Fe2SiO4) and Phlogopite (KMg3(AlSi3O10(OH)2), due to the process of phase changes in manganese ore. Mineral mineral appeared on roasting with time variations 60 minutes, 90 minutes and 120 minutes, as well as appearing on the variation in temperatur of 500 °C, 700 °C and 900 °C.

On testing in the SAF used basicity based stoichiometri with a value of 1.17, 1.32, 1.15 and reference basicity 0.7 based on the Bobby et al, 2015 reserach. Influence of basicity resulted in an increase of weight of metal and decrease the weight of slag during processing in the SAF. In addition basicity stoichiometry produces only ferromangan with Mn = 35.47% and reference basicity 0.7 generate Ferromangan with Mn = 60%.

The results of this study showed that increasing the ratio of Mn/Fe using beneficiation could reach a ratio 6.11. While the process of making FeMn using low grade manganese ore at Submerged arc furnace can produce 60% Mn grade with controls on basicity to reduce the volume of slag, improve and raise the level of heavy metals Mn."