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Nurhayati Indah Ciptasari

Efek scale-up pada proses pelindian Bijih Nikel kadar rendah jalur hidrometalurgi = Effect process scale-up on low grade of nickel ore leaching hydrometallurgical path

"ABSTRAK

Bijih nikel laterit banyak tersedia di Indonesia bagian timur, seperti Pulau

Sulawesi dan kepulauan Maluku termasuk pulau-pulau kecil di sekitarnya.

Faktanya, sejauh ini bijih nikel kadar rendah tipe limonit belum diproses karena

kandungan nikelnya sangat rendah. Dalam tesis ini kami membahas hasil terbaru

pada efek scale-up dari pengolahan bijih nikel kadar rendah melalui pendekatan

hidrometalurgi. Proses ini dipilih karena kandungan magnesium yang rendah

dalam bijih dan konsumsi energi yang minimal selama pemprosesan. Proses yang

dipilih yaitu pelindian atmosferik. Variabel-variabel proses yang dipelajari adalah

persen pelarut, temperatur proses, waktu pelindian, ukuran mesh dan efek scaleup.

Karakterisasi residu dipelajari dengan menggunakan SEM, XRD dan XRF.

Sementara hasil proses pelindian dalam bentuk larutan dianalisis menggunakan

AAS untuk menentukan fraksi elemen terlarut. Hasil penelitian saat ini

menunjukkan bahwa pelindian bijih nikel kadar rendah jalur hidrometalurgi

menggunakan 37% asam klorida pekat telah mengekstraksi Ni dan Fe dari bijih

dengan hasil 76,7% dan 75,8%. Hal ini dicapai pada kondisi proses berikut:

temperatur optimum 90oC, 200 mesh dan kecepatan pengadukan 300 rpm.

Selanjutnya, pada saat bahan baku tersebut ditingkatkan hingga 100 gram limonit,

hasil tersebut menurun menjadi 55% dan 65 %. Selanjutnya, terjadi penurunan

hingga sekitar 45% ketika bahan baku ditingkatkan dua kali lipat menjadi 200

gram limonit.

Abstract

The laterite nickel ores are abundantly available in the eastern part of Indonesia

island like Sulawesi and Maluku islands including many small islands around

them. The fact that nickel ores called limonite have not been processed so far due

to the nickel content is very low. In this thesis, we discussed our recent works on

the effects of scaling up of processing for low grade nickel ores through a

hydrometallurgical approach. This was selected due to the low magnesium

content in the ores and minimum energy consumption during processing. The

selected process is the atmospheric leaching. Processing variables which were

studied including the optimum percentage of solvent, processing temperatures,

leaching time, mesh sizing and the scale-up effects. Characterization of the

residue was studied using SEM, XRD and XRF. While the materials which

deposited in the leaching filtrate were analyzed using AAS to determine the

fraction of dissolved elements. Results of current recearch work showed that

leaching of low grade nickel ore using a hydrometallurgical route using 37%

concentrated hydrochloric acids have resulted extracted materials of Ni and Fe

with extraction yields 76.7% and 75.8% respectivelly. This was obtained at the

following processing conditions: optimum temperature 90°C; 200 mesh and the

stirring speed of 300 rpm. Further to this, when the feedstock was scaled up to

100 grams limonite, the yields were decreased to 55 % and 65 % for Ni and Fe

respectively. A further decreased to about 45 % occurred when the feedstock was

doubled to 200 grams limonite."

2012

T31559

UI - Tesis Open Universitas Indonesia Library

Suprayogi

Studi pengaruh penambahan batubara pada proses roasting reduction bijih nikel saprolit dan pelindian (leaching) dalam larutan asam sulfat 1 molar = Study of coal addition effect on roasting reduction process of saprolitic nickel ore and leaching in sulfuric acid 1 molar

"Deposit laterite merupakan salah satu jenis bijih nikel yang paling berlimpah di alam. Di Indonesia khususnya di Kabupaten Pomala, Sulawesi Tenggara memiliki deposit laterite yang tergolong tinggi. Salah satu mineral yang ada di dalam lapisan laterite yaitu bijih nikel saprolit yang memiliki kadar unsur nikel yang lebih tinggi dibandingkan lapisan lainnya seperti limonit.

Untuk mendapatkan recovery nikel yang efektif dan efisien, diperlukan suatu pengembangan penelitian proses ekstraksi. Pada penelitian ini akan dilakukan beberapa proses seperti separasi dengan fluida air, pirometalurgi (roasting reduction) dan hidrometalurgi (pelindian). Penelitian ini akan membahas pengaruh penambahan reduktor yang berasal dari batubara dengan kadar yang berbeda-beda yaitu 8%, 16%, 24% dan 32%. Untuk mengetahui komposisi kimia dari bijih saprolit yang murni dan yang telah dilakukan proses separasi, akan dilakukan pengujian EDX (Energy Dispersive X-Ray) terlebih dahulu.

Sebelum ketahap hidrometalurgi, sampel dengan masing-masing penambahan batubara tersebut dilakukan proses roasting reduction pada temperatur 1250oC di dalam furnace carbolyte. Selanjutnya akan dilakukan pengujian STA dan XRD dengan tujuan untuk melihat senyawa-senyawa yang terdapat pada bijih nikel saprolit tersebut. Setelah tahap ini selesai dilakukan, sampel dilindi dengan menggunakan larutan Asam Sulfat 1 Molar dalam waktu 90 menit.

Dari hasil yang diperoleh, pada proses pelindian asam sulfat dengan konsentrasi 1 Molar, persentase recovery nikel yang tertinggi berada pada bijih saprolit yang ditambahkan dengan batubara sebanyak 16% dengan perolehan Nikel nya yaitu sebesar 59.85% (persentase optimum).

Laterite deposit is one of the most abundant ore in nature. In Indonesia, especially in Pomala regency, Southeast Sulawesi, has a high laterite deposit. One of the minerals in the laterite layer is saprolite nickel ore which has a higher nickel content than the other layers, such as limonite.
To get recovery of nickel with effective and efficient, a study about development of extraction process is needed. This research will conduct several processes such as float and sink process, pyrometallurgy (roasting reduction) and hydrometallurgical (leaching). This research also will disscus the effect of addition of coal as reductor, with varied levels of coal: 8%, 16%, 24% and 32%. To determine the chemical composition of saprolite ore that have been treated by float and sink process, EDX (Energy dispersive X-Ray) test is performed.
Before hydrometallurgy process is conducted, the samples that have been added by varied levels of coal was reduction roasted at temperature 1250oC in Carbolyte furnace. Further testing will be conducted by the STA and XRD with purpose to determine the compounds presence in the saprolite nickel ore. After that stage, the sample is leached in Sulfuric Acid at 1 Molar for 90 minutes.
From the obtained results, the process of leaching with sulfuric acid at 1 Molar, the recovery percentage of nickel from 16% of coal addition is the highest with obtained value 59.85% (optimum percentage)."

Depok: Fakultas Teknik Universitas Indonesia, 2012

S43343

UI - Skripsi Open Universitas Indonesia Library

Dwiki Prasetya Ernanto

Studi Pengaruh Agen Presipitasi NaOH dalam Proses Presipitasi Mixed Hydroxide Precipitate (MHP) pada Sampel hasil Pelindian Bijih Nikel Laterit = Study of the effect of NaOH Precipitation agent in the precipitation process of mixed hydroxide precipitate (MHP) on nickel ore leaching samples

"Penelitian ini merupakan rangkaian penelitian lanjutan dari studi iron removal pada sampel pregnant leach solution (PLS) hasil pelindian bijih nikel laterit. Penelitian ini berfokus pada pengendapan unsur nikel dan kobalt yang terkandung di dalam sampel dengan proses hidrometalrugi menjadi produk mixed hydroxide precipitate (MHP). Sebelumnya, sampel PLS sudah dilakukan penghilangan kadar besi dengan penambahan kalsium karbonat sebanyak 2 kali dengan kandungan 25% w/w dan 12,5% w/w yang dilakukan selama 2 jam dan 1 jam pada temperature 90oC. Hasil pengurangan besi yang dilakukan menunjukkan pengurangan kandungan besi dari sampel bijih PLS sebesar 75% dari kandungan semula yang sudah diuji dengan ICP. Selanjutnya penelitian dilanjutkan untuk memproduksi MHP dengan penambahan larutan NaOH sebesar 4M kedalam larutan PLS yang sudah dikurangi kandungan besinya dengan presipitasi sebelumnya. Presipitasi dengan NaOH dilakukan hingga mencapai pH 7 lalu dipanaskan hingga suhu 60oC selama 1 jam. Hasil penelitian yang dilakukan hingga pH 7 menunjukkan hasil yang belum optimal dengan kandungan nikel yang hanya sebesar 5% dari total kandungan setelah dilakukan proses pengurangan kadar besi yang kedua kali. Penelitian ini menemukan beberapa faktor yang mungkin menyebabkan tidak bertambahnya kadar nikel dalam produk MHP setelah dilakukan presipitasi dengan larutan NaOH. Tingkat viskositas yang terlalu tinggi selama titrasi, masih tingginya kadar pengotor yang terkandung dalam larutan pasca pengurangan besi, serta endapan yang tidak kristalin menjadi faktor yang membuat larutan lewat jenuh dan kurang optimalnya hasil pasca penelitian. Waktu penyimpanan larutan pasca titrasi juga menjadi faktor yang membuat kandungan nikel dan kobalt tereduksi dan pengotor tidak terikat sempurna.

This research is a follow-up research series from the study of iron removal on pregnant leach solution (PLS) samples from the leaching of laterite nickel ore. This research focuses on the deposition of Nickel and Cobalt elements contained in the sample by a hydrometallurgical process to become a mixed hydroxide precipitate (MHP) product. Previously, the PLS sample had iron content removed with the addition of calcium carbonate 2 times with a content of 25% w/w and 12.5% w/w for 2 hours and 1 hour at a temperature of 90oC. The results of the iron reduction carried out showed a reduction in the iron content of the PLS ore samples by 75% of the original content that had been tested with ICP. Furthermore, the research continued to produce MHP with the addition of 4M NaOH solution into the PLS solution which had been reduced in iron content by previous precipitation. Precipitation with NaOH was carried out until it reached pH 7 and then heated to a temperature of 60oC for 1 hour. The results of the research carried out up to pH 7 showed that the results were not optimal with the nickel content only 5% from all the contents after the second process of reducing the iron content was carried out. This study found several factors that might cause the nickel content to not increase in MHP products after precipitation with NaOH solution. Viscosity levels that are too high during titration, high levels of impurities contained in the solution after iron reduction, and non-crystalline precipitates are factors that make the solution supersaturated and post-test results are less than optimal. The storage time of the post-titration solution is also a factor that makes the reduced nickel and cobalt content and impurities not completely bound."

Depok: Fakultas Teknik Universitas Indonesia, 2022

S-pdf

UI - Skripsi Membership Universitas Indonesia Library

Rian Saputra

Pengaruh reduksi roasting pada bijih nikel saprolit dan perbedaan konsentrasi pada pelindian atmosferik asam sulfat = The effect reduction roasting of nickel using saprolite ore and various concentration of atmospheric sulphuric acid leaching

"Sources nickel laterite deposit of the world are mostly found in the tropic such as Indonesia. The initial composition of nickel saprolite ore is characterized by XRF. Saprolte ore was reduced use coal 15% wt at 1000°C for 60 minutes. The result of reduction is characterized by XRD. Effect of roasting reduction to recovery nickel also affect the result leaching use solvent sulphuric acid (H2SO4) for 240 minutes at 100°C with varying concentrations of 0.5 M, 1 M, and 2 M. The content of nickel dissolved in pregnant leach solution calculated using Atomic Absorbance Spectroscopy (AAS).

Result of XRD characterization shows phase transformation into Fe3O4, NiO, and FeNi after reduction roasting. Sulphuric Acid at concentration 1 Molar has the highest nickel recovery with 52.75% in reduced saprolite ore."

Depok: Fakultas Teknik Universitas Indonesia, 2016

S63620

UI - Skripsi Membership Universitas Indonesia Library

Achmad Shofi

Reduksi selektif karbotermik bijih nikel kadar rendah dengan penambahan aditif Na2SO4 dan NaCl = carbothermic selective reduction of low grade nickel ore with addition of Na2SO4 dan NaCl

"Proses reduksi selektif dan pemisahan magnetik bijih nikel kadar rendah dengan kandungan Ni, Fe, Mg, dan Si masing-masing sebesar 1,4 , 50,5 , 1,81 , dan 16,5 telah dilakukan melalui mekanisme dua tahap peningkatan panas dengan penambahan aditif Na2SO4 dan NaCl. Na2SO4 dan NaCl diketahui mampu membebaskan nikel dan besi dari fasa olivin dan juga menekan metalisasi besi dengan proses sulfidasi, kloridasi, dan segregasi. NaCl yang ditambahkan bertujuan untuk menggantikan sebagian Na2SO4 untuk mengurangi kandungan sulfur sisa pada konsentrat yang dihasilkan. Penahanan pada temperatur awal pre-heating dilakukan untuk memaksimalkan reaksi reduksi nikel dalam fasa goethit sekaligus menekan reduksi besi oksida, sedangkan penahanan pada temperatur lanjut reduksi bertujuan untuk proses pembebasan nikel pada fasa lizardit dan mendukung pertumbuhan partikel feronikel dengan mekanisme aglomerasi partikel pada fasa leleh sistem Fe-FeS eutektik yang terbentuk. Oleh karena itu, kedua perlakuan pemanasan tersebut dapat meningkatkan kadar, perolehan dan derajat metalisasi dari nikel. Hasil optimal didapatkan pada bijih hasil reduksi dengan penambahan 11 satu stoikiometri arang cangkang sawit, 10 Na2SO4, dan 10 NaCl pada temperatur pemanasan awal 500 C selama 90 menit, diikuti dengan pemanasan lanjut selama 90 menit pada temperatur 1150 C, yang menghasilkan konsentrat feronikel dengan kadar dan perolehan nikel masing-masing sebesar 5,53 dan 85,89 , serta derajat metalisasi nikel sebesar 93,69 . Ukuran partikel feronikel yang dihasilkan pada sampel tersebut berukuran 61,75 m, jauh lebih besar dibandingkan ukuran butir sampel tanpa penambahan aditif atau temperatur reduksi yang lebih rendah 1050 C yaitu berturut-turut sebesar 5 m dan 28,5 m. Fasa-fasa yang terbentuk dengan penambahan aditif Na2SO4 dan NaCl yaitu kamasit FeNi , wustit FeS , fayalit, dan nepheline, yang merupakan indikasi berjalannya proses optimasi reduksi selektif dengan memaksimalkan pembebasan nikel dari fasa olivin dan menekan pembentukan logam besi sehingga perolehan, kadar, dan derajat metalisasi nikel meningkat.

Selective reduction and magnetic separation process of low grade nickel ore with Ni, Fe, Mg and Si contents of 1.4 , 50.5 , 1.81 and 16.5 has been conducted with two stage thermal upgrading mechanism with addition of Na2SO4 and NaCl. These two additives is known to be capable of liberating nickel and iron from olivine phase, as well as suppressing iron metallization with sulphidation, chloridization and segregation process. The addition of NaCl was aimed to substitute some part of Na2SO4 to reduce residual sulphur content of the produced ferronickel concentrate. The retention of roasting at initial temperature pre heating was done to maximize reductive reaction of nickel within goethite phase and to suppress the reduction of iron oxide, while the retention of roasting at final temperature reduction was done to focus the nickel liberation from lizardite phase and to promote ferronickel particle growth using agglomeration mechanism within the formed molten phase of Fe FeS eutectic system. Therefore, these two thermal treatment could improve the grade, recovery and metallization of nickel. The optimal result obtained was the reduced ore with 11 palm kernel shell reductor, 10 Na2SO4, and 10 NaCl at initial roasting temperature of 500 C for 90 minutes, followed by final roasting temperature of 1150 C for 90 minutes which resulted ferronickel concentrat with 5.53 grade, 85.9 recovery and 93.86 metallization. The resulting particle size of the aformentioned sample is 61.75 m, far bigger compared to sample without additives or lower reducing temperature 1050 C which is 5 m and 28.5 m, respectively. The formed phase of the reduced ore with the addition of Na2SO4 and NaCl was kamacite FeNi , wustite FeS , fayalite and nepheline, which indicates the optimization process of selective reduction through maximalizing nickel liberation from olivine and suppresing the formation of metallic iron resulting in improved nickel grade, recovery and metallization."

Depok: Fakultas Teknik Universitas Indonesia, 2018

T49604

UI - Tesis Membership Universitas Indonesia Library

Ahmad Royani

Pembuatan MnO2 dari Bijih Mangan kadar rendah dengan proses pelindian pemanggangan reduktif = Fabrication of mno2 from low grade manganese ores with reductive roast leaching

"ABSTRAK

Pelindian mangan dari bijih mangan kadar rendah telah berhasil dilakukan menggunakan larutan sulfat. Pada percobaan ini, bijih mangan dipanggang dengan arang kayu sebagi reduktor pada 700 oC selama 120 menit. Kemudian kalsin hasil pemanggangan dilindi menggunakan larutan asam sulfat. Parameter proses pelindian yang diamati meliputi pengaruh kecepatan pengadukan, konsentrasi asam, temperatur, waktu dan persen padatan terhadap mangan terekstrak. Hasil optimum didapat pada proses pelindian dengan konsentrasi 12% H2SO4, kecepatan pengadukan 400 rpm, rasio padatan 1:10, dan temperatur 75 oC selama 3 jam dengan mangan terekstrak sebesar 84,61%. Kinetika reaksi pelindian mangan dalam asam sulfat dikendalikan oleh proses difusi dengan nilai energi aktivasi sebesar 4,88 KJ/mol.

ABSTRACT
The leaching of manganese from low-grade manganese ores in aqueous sulfuric acid solution was investigated. In this study, manganese ores were prepared by reduction roasting using charcoal as a reductant at 700 oC for 120 min. The roasted samples were then leached with aqueous sulfuric acid solution. The effects of agitation rate, sulfuric acid concentration, solid/liquid mass ratio, leaching temperature and leaching time on the leaching efficiency of manganese were studied. The optimal leaching conditions are achieved at 12% H2SO4, agitation rate of 400 rpm, solid/liquid mass ratio of 1:10, and the leaching temperature of 75 oC for 180 min. Under the optimal condition, the leaching efficiency of manganese can reach 84.61%. The kinetical reaction of manganese dissolution in aqueous sulfuric acid solution was found to be controlled by diffusion process with activation energy is 4.88 KJ/mol."

Depok: Universitas Indonesia, 2016

T45188

UI - Tesis Membership Universitas Indonesia Library

Satrio Amarela

Peningkatan kadar dan rasio mangan pada bijih mangan lokal kadar rendah melalui proses benefisiasi dengan variabel temperatur pada reduction roasting = The enhancement of manganese grade and its ratio from local low grade manganese ore through beneficiation process with the variation of temperature on reduction roasting process

"ABSTRAK

Sekitar 90% bijih mangan di dunia digunakan untuk pembuatan ferromangan dan

ferrosilicomangan sebagai material paduan dalam proses steel making. Penambahan

unsur mangan dalam wujud paduan ferromangan pada proses steel making mampu

meningkatkan kekerasan dan ketangguhan baja. Ferromangan diperoleh dari

pengolahan bijih mangan metallurgical grade dengan proses peleburan. Bijih mangan

kadar rendah, melalui penelitian sebelumnya oleh Hendri (2015) dan Noegroho (2016),

tidak ekonomis untuk dilebur menjadi ferromangan 􀁇􀁈􀁑􀁊􀁄􀁑􀀃􀀰􀁑􀀃􀂕􀀙􀀓􀀈􀀃􀁖􀁈􀁋􀁌􀁑􀁊􀁊􀁄􀀃􀁅􀁌􀁍􀁌􀁋􀀃

mangan kadar rendah harus dibenefisiasi terlebih dahulu untuk meningkatkan kadar

mangan dan rasio Mn/Fe dalam bijih.

Bijih mangan kadar rendah pada penelitian ini merupakan bijih mangan lokal asal

Lampung dan Jawa Timur. Benefisiasi dilakukan menggunakan teknik gravity

separation dan reduction roasting selama 30 menit menggunakan 20% batu bara

dilanjutkan magnetic separation pada medan magnet ±500 gauss. Bijih mangan

dihaluskan ke dalam ukuran -20+40, -40+60, dan -60+80 mesh dan temperatur

reduction roasting divariasikan pada 500oC, 700oC, dan 900oC. Pengujian XRD dan

XRF dilakukan dalam mengarakterisasi sampel awal dan hasil.

Rasio Mn/Fe dan kadar mangan pada bijih asal Lampung masing-masing

sebesar 0,90 dan 7,83% sementara pada bijih asal Jawa Timur masing-masing sebesar

1,356 dan 18,52%. Setelah dibenefisiasi, hasil terbaik dari proses gravity separation

pada bijih Lampung tercapai pada rasio Mn/Fe 0,95 dengan kadar Mn 9,4% pada

89,75% recovery berat sementara pada bijih Jawa Timur diperoleh pada rasio Mn/Fe

3,32 dengan kadar mangan 40,48% pada 2,09% recovery berat. Selanjutnya, hasil

terbaik dari reduction roasting dilanjutkan magnetic separation pada bijih Lampung

diperoleh pada rasio Mn/Fe 1,96 dan kadar mangan 6,81% pada 36 wt% recovery,

sementara pada bijih Jawa Timur, tercapai pada rasio Mn/Fe 3,99 dan kadar mangan

34,31% pada 44 wt% recovery.

ABSTRACT

About 90% of manganese ore is utilized for ferromanganese and

ferrosilicomanganese production as alloying metal in the steel making process. The

addition of manganese in the form of ferromanganese to the steel making process is

able to increase hardness and toughness of steel. Ferromanganese is obtained from the

metallurgical grade manganese ore processing through the smelting process. Low grade

manganese ore, according to the previous research from Hendri (2015) and Noegroho

(2016), was not economic for direct smelting to obtain ferromanganese with Mn 􀂕􀀙􀀓􀀈􀀑􀀃

Therefore, low grade manganese ore must be beneficiate first to enhance the

manganese grade and its ratio.

Low grade manganese ore in this research are a local ore from Lampung and

East Java. The steps on the beneficiation process are including gravity separation and

reduction roasting for 30 minutes using 20% of coal followed by magnetic separation

at the magnetic intensity of ±500 Gauss. The particle size was reduced into -20+40, -

40+60, and -60+80 mesh and the temperature of reduction roasting was varied at 500oC,

700oC, and 900oC. XRD and XRF testing was conducted for the characterization of ore

and the sample results.

Mn/Fe ratio and manganese content in Lampung ore is respectively 0.9 and

7.83%, while in East Java ore is respectively 1.356 and 18.52%. After beneficiation,

the best results from gravity separation of Lampung ore was obtained at 0.95 of Mn/Fe

ratio and 9.4% of manganese content at 89.75% of weight recovery, while in East Java

ore was obtained at 3.32 of Mn/Fe ratio and 40.48% of manganese content at 2.09% of

weight recovery. Then, the best results of reduction roasting followed by magnetic

separation of Lampung ore was obtained at 1.96 of Mn/Fe ratio and 6.81% of

manganese content at 36% of weight recovery, while in East Java ore was obtained at

3.99 of Mn/Fe ratio and 34.31% of manganese content at 44% weight recovery.

2016

S63231

UI - Skripsi Membership Universitas Indonesia Library

Hendri Saputra

Proses pembuatan ferromangan pada submerged arc furnace dengan menggunakan campuran bijih mangan kadar rendah dan kadar menengah = Ferromanganese process using submerged arc furnace with mixed low grade and medium grade manganese ore

"[ABSTRAK

Potensi cadangan bijih mangan di Indonesia cukup besar, namun terdapat

di berbagai lokasi yang tersebar di seluruh Indonesia. Komoditi ini menjadi bahan

baku 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 memperbaiki

sifak-sifat mekanik dari produk yang dihasilkan.

Penelitian ini dilakukan untuk mempelajari pengaruh proses pencanpuran

bijih 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 berasal

dari Jember, Jawa Timur (27,7 %Mn-4,4 %Fe-14,7%Si) sebagai bahan baku untuk

pembuatan logam FeMn dengan kandungan minimal sebesar 50 %Mn. Penelitian

ini dilakukan sebanyak 5 kali percobaan dengan variasi pada campuran bijih Mn

yaitu [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 Arc

Furnace (SAF) dengan input berupa bijih Mn sebagai bahan baku utama, kokas

sebagai reduktor, dan kapur sebagai aditif. Ketiga bahan baku tersebut dilebur

hingga mencapai temperatur 1500 oC. Untuk mengetahui kualitas bahan baku dan

produk FeMn yang dihasilkan, dilakukan analisa seperti XRF (X-Ray

Fluoroscence), XRD (X-Ray Diffraction), AAS (Atomic Absorbtion Spectrometry),

dan Proksimat.

Dari hasil penelitian didapatkan bahwa untuk percobaan [1] diperoleh

logam FeMn sebanyak 5,2 Kg dengan kadar 54,05 %Mn, percobaan [2] diperoleh

logam FeMn sebanyak 4,75 Kg dengan kadar 50,03 %Mn, percobaan [3] diperoleh

logam FeMn sebanyak 4,6 Kg dengan kadar 36,44 %Mn, percobaan [4] diperoleh

logam 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 dari

proses pencampuran (Mn-blend) dalam pembuatan ferromangan ini adalah

semakin banyak komposisi bijih Mn kadar menengah (MG) yang digunakan,

menyebabkan (a) semakin banyaknya kokas dan semakin berkurangnya kapur yang

dibutuhkan, (b) meningkatnya yield, jumlah produk, serta kandungan persentase

Mn dari FeMn yang dihasilkan, dan (c) semakin rendahnya konsumsi energi yang

dibutuhkan.

ABSTRACT

The potential reserve of manganese ore in Indonesia is very large, but it

was located in different locations spread throughout Indonesia. Manganese ore is

one of raw material in producing ferromanganese that is not replaceable in the

world steel industry. Ferromanganese (FeMn) is an alloying metal that contained

of 75% Manganese (Mn) and 25% Iron (Fe) which is generally used in the process

of iron/steel making to improve its mechanical properties.

In this experiment, ferromanganese production was conducted by blending

two kinds of manganese ore, that was low grade Mn ore (LG) which derived from

Tanggamus, 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), to

obtain ferromanganese with a minimum content of 50 %Mn. The composition of

Mn-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 manganese

ore was processed by using Submerged Arc Furnace (SAF). Cokes and limestone

was added into the furnace as reductant and flux agent, respectively. Those raw

materials are smelted until 1500 °C. To determine the composition of raw materials

and the product of FeMn, analysis such as XRF (X-Ray Fluorescence), XRD (XRay

Diffraction), AAS (Atomic Absorption Spectrometry), and proximate have to be

done.

From each composition of Mn-blend above in this experiment, it was

obtained 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 this

ferromanganese production was by the increasing composition of the medium

grade manganese ore (MG) that will cause: (a) the increasing number of cokes and

the decreasing of limestone required, (b) the increasing of yield, the number of

products, and also the percentage of manganese content FeMn, and (c) the

decreasing of energy consumption required., The potential reserve of manganese ore in Indonesia is very large, but it