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The effect of composition and shape variations on compressive strength slag depressant Bening Nurul Hidayah Kambuna; Soesaptri Oediyani; Della Izzaty Salman; Kusnadi Kusnadi
Jurnal Teknika Vol 17, No 2 (2021): Available Online in November 2021
Publisher : Faculty of Engineering, Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36055/tjst.v17i2.12371

The steel-making process begins with a reduction process carried out in a blast furnace (BF) then continues with the refining process in the converter. In the refining process, there is a slag foam formed from the reaction of oxygen with hot metal. An additive called a slag depressant is needed to reduce foam formation in the slag. Slag depressants are made using paper mill waste, limestone, and slag blast furnaces. This study aims to increase the compressive strength of the slag depressant by varying the composition and shape variations. Variations in the composition used were with and without the addition of BF slag, while variations in the shapes used were cylinder, round, and cube. Making slag depressants begins with the stages of mixing, compacting, and drying. Slag depressant drying is carried out in the sun for ± eight days. The slag depressant raw material was analyzed using the XRF method to see the chemical composition of the raw material. The resulting slag depressant was then analyzed for proximate analysis, compression test, drop test, and porosity test. In this study, the best quality slag depressant with high compressive strength and low porosity values is the slag depressant in a cylindrical shape, and the ratio of paper waste to limestone is 80:20%. The resulting compressive strength value is 1207.5 N/cm2 and has a porosity of 34.7%. The addition of BF slag in this study was proven to affect the compressive strength of the slag depressant. The highest compressive strength value was achieved by adding 10% slag blast furnace to 10%, which was 862.08 N/cm2. Proses pembuatan baja diawali dengan proses reduksi yang dilakukan dalam blast furnace (BF) kemudian dilanjutkan dengan proses pemurnian dalam converter. Dalam proses pemurnian, terdapat gelembung/busa slag (slag foam) yang terbentuk dari reaksi oksigen dengan hot metal. Untuk mengurangi pembentukan busa pada slag maka diperlukan bahan aditif yang disebut dengan slag depressant. Slag depressant dibuat dengan menggunakan limbah pabrik kertas, batu kapur dan slag blast furnace. Penelitian ini bertujuan untuk meningkatkan kekuatan tekan slag depressant dengan melakukan variasi komposisi dan variasi bentuk. Variasi komposisi yang digunakan yaitu dengan dan tanpa penambahan slag BF sedangkan variasi bentuk yang digunakan yaitu silinder, bulat dan kubus. Proses pembuatan slag depressant diawali dengan tahapan mixing, kompaksi dan pengeringan. Pengeringan slag depressant dilakukan di bawah sinar matahari ±8 hari. Bahan baku slag depressant dianalisis dengan metode XRF untuk melihat komposisi kimia bahan baku tersebut. Slag depressant yang dihasilkan kemudian dilakukan analisis proksimat, uji tekan, uji jatuh dan uji porositas. Pada penelitian ini didapatkan slag depressant dengan kualitas paling baik dengan nilai kuat tekan tinggi dan porositas rendah yaitu pada slag depressant bentuk silinder dan perbandingan limbah kertas dengan batu kapur sebesar 80: 20 %. Nilai kuat tekan yang dihasilkan sebesar 1207,5 N/cm2 dan porositas sebesar 34,7%. Penambahan slag BF dalam penelitian ini terbukti mempengaruhi kuat tekan slag depressant. Nilai kuat tekan tertinggi dicapai pada penambahan 10% slag blast furnace 10% yaitu sebesar 862,08 N/cm2.

Pelarutan Emas pada Pelindian Konsentrat Emas Hasil Roasting Menggunakan Reagen Tiosianat Fika Rofiek Mufakhir; J M Sinaga; Soesaptri Oediyani; Widi Astuti
Jurnal Rekayasa Proses Vol 13, No 1 (2019)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

A B S T R A C TDissolution of gold from roasting concentrate of gold ore using potassium thiocyanate with the presence of ferric chloride as an oxidizer was investigated. The concentrate was taken from Lengkukai gold mine. Gold ore particles under 53 µm in size were roasted at varied temperature, separated using wet magnetic separator, and finally leached. The X-ray diffraction (XRD) analysis showed that there were phase changes after roasting with the emergence of new phases such as hematite, pyrrhotite, and almandine. Leaching of gold concentrate after roasting and magnetic separation showed that gold was in non-magnetic concentrate at 950oC with the highest gold dissolution of 0.95 mg/L, while magnet concentrate was completely absent. Experiments with the addition of Fe3+ ion oxidizers for 24-hour range did not have significant effect on gold dissolution. The highest gold concentration obtained of 2.29 mg/L was obtained at 12 hours with 0.1 M FeCl3. The increase of thiocyanate reagent concentrations, which showed a linear correlation to gold dissolution, produced up to 2.25 mg/L of gold concentration (12 hours at 0.3 M KSCN).Keywords: ferric ion gold dissolution; gold concentrate; roasting; thiocyanate A B S T R A KPelarutan emas dari konsentrat hasil roasting bijih emas tambang Lengkukai menggunakan reagen pelindi kalium tiosianat dengan penambahan ferric chloride sebagai oksidator telah diteliti. Partikel bijih emas dengan ukuran di bawah 53 µm di-roasting pada berbagai temperatur kemudian dipisahkan menggunakan pemisah magnetik basah dan akhirnya dilindi. Hasil analisis X-ray diffraction (XRD) menunjukkan adanya perubahan fase setelah roasting dengan munculnya fase-fase baru yaitu hematit, pirohitit dan almandin. Pelindian konsentrat emas hasil roasting dan pemisahan magnetik menunjukan emas berada pada konsentrat non magnet temperatur roasting 950 oC dengan pelarutan emas paling tinggi sebesar 0,95 mg/L, berbeda dengan konsentrat magnet yang sama sekali tidak ada. Percobaan dengan penambahan oksidator ion Fe3+ selama rentang 24 jam tidak memberikan efek yang signifikan terhadap pelarutan emas. Dari penelitian ini didapatkan konsentrasi emas tertinggi sebesar 2,29 mg/L pada 12 jam dengan konsentrasi FeCl3 0,1 M. Sedangkan penambahan konsentrasi reagen tiosianat, yang menunjukan hubungan linier terhadap pelarutan emas, menghasilkan konsentrasi besar hingga 2,25 mg/L selama 12 jam pada konsentrasi KSCN 0,3 M.Kata kunci: ion besi III; konsentrat emas; pelarutan emas; roasting; tiosianat

EFFECT OF NICKEL PULSED ELECTRODEPOSITION PARAMETERS ON DEPOSIT MICROSTRUCTURE AND CORROTION RATE AISI 410 Agnes Stephani; Soesaptri Oediyani; Yulinda Lestari; Efendi Mabruri
Widyariset Vol 4, No 2 (2018): Widyariset
Publisher : Pusbindiklat - LIPI

Nickel pulse electrodeposition is one of the coating methods that used to increase the corrosion resistance and improve the mechanical properties. In this study, nickel was used as the anode and martensitic stainless steel 410 was used as the cathode. The solution used in the method of nickel pulse electrodeposition include nickel sulfate, nickel chloride, and boric acid. Pulse electrodeposition parameters are variation of duty cycle of 70, 80, 90% and frequency variations valued at 0.1, 1, 10, and 20 kHz. Temperatures used in research nickel pulse electrodeposition at 50 ° C, with a current density of 15 A / dm² and 18 minutes. The Scanning Electron Microscopy analysis determine the microstructure and grain size changes after a nickel pulse electrodeposition. The polarization test determine optimum rate of corrosion when 90 % duty cycle and 20 kHz frequency.

EFFECT OF NICKEL PULSED ELECTRODEPOSITION PARAMETERS ON DEPOSIT MICROSTRUCTURE AND CORROTION RATE AISI 410 Agnes Stephani; Soesaptri Oediyani; Yulinda Lestari; Efendi Mabruri
Widyariset Vol 4, No 2 (2018): Widyariset
Publisher : Pusbindiklat - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/widyariset.4.2.2018.143-152

Nickel pulse electrodeposition is one of the coating methods that used to increase the corrosion resistance and improve the mechanical properties. In this study, nickel was used as the anode and martensitic stainless steel 410 was used as the cathode. The solution used in the method of nickel pulse electrodeposition include nickel sulfate, nickel chloride, and boric acid. Pulse electrodeposition parameters are variation of duty cycle of 70, 80, 90% and frequency variations valued at 0.1, 1, 10, and 20 kHz. Temperatures used in research nickel pulse electrodeposition at 50 ° C, with a current density of 15 A / dm² and 18 minutes. The Scanning Electron Microscopy analysis determine the microstructure and grain size changes after a nickel pulse electrodeposition. The polarization test determine optimum rate of corrosion when 90 % duty cycle and 20 kHz frequency.

Pelarutan Emas pada Pelindian Konsentrat Emas Hasil Roasting Menggunakan Reagen Tiosianat Fika Rofiek Mufakhir; J M Sinaga; Soesaptri Oediyani; Widi Astuti
Jurnal Rekayasa Proses Vol 13, No 1 (2019)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

A B S T R A C TDissolution of gold from roasting concentrate of gold ore using potassium thiocyanate with the presence of ferric chloride as an oxidizer was investigated. The concentrate was taken from Lengkukai gold mine. Gold ore particles under 53 µm in size were roasted at varied temperature, separated using wet magnetic separator, and finally leached. The X-ray diffraction (XRD) analysis showed that there were phase changes after roasting with the emergence of new phases such as hematite, pyrrhotite, and almandine. Leaching of gold concentrate after roasting and magnetic separation showed that gold was in non-magnetic concentrate at 950oC with the highest gold dissolution of 0.95 mg/L, while magnet concentrate was completely absent. Experiments with the addition of Fe3+ ion oxidizers for 24-hour range did not have significant effect on gold dissolution. The highest gold concentration obtained of 2.29 mg/L was obtained at 12 hours with 0.1 M FeCl3. The increase of thiocyanate reagent concentrations, which showed a linear correlation to gold dissolution, produced up to 2.25 mg/L of gold concentration (12 hours at 0.3 M KSCN).Keywords: ferric ion gold dissolution; gold concentrate; roasting; thiocyanate A B S T R A KPelarutan emas dari konsentrat hasil roasting bijih emas tambang Lengkukai menggunakan reagen pelindi kalium tiosianat dengan penambahan ferric chloride sebagai oksidator telah diteliti. Partikel bijih emas dengan ukuran di bawah 53 µm di-roasting pada berbagai temperatur kemudian dipisahkan menggunakan pemisah magnetik basah dan akhirnya dilindi. Hasil analisis X-ray diffraction (XRD) menunjukkan adanya perubahan fase setelah roasting dengan munculnya fase-fase baru yaitu hematit, pirohitit dan almandin. Pelindian konsentrat emas hasil roasting dan pemisahan magnetik menunjukan emas berada pada konsentrat non magnet temperatur roasting 950 oC dengan pelarutan emas paling tinggi sebesar 0,95 mg/L, berbeda dengan konsentrat magnet yang sama sekali tidak ada. Percobaan dengan penambahan oksidator ion Fe3+ selama rentang 24 jam tidak memberikan efek yang signifikan terhadap pelarutan emas. Dari penelitian ini didapatkan konsentrasi emas tertinggi sebesar 2,29 mg/L pada 12 jam dengan konsentrasi FeCl3 0,1 M. Sedangkan penambahan konsentrasi reagen tiosianat, yang menunjukan hubungan linier terhadap pelarutan emas, menghasilkan konsentrasi besar hingga 2,25 mg/L selama 12 jam pada konsentrasi KSCN 0,3 M.Kata kunci: ion besi III; konsentrat emas; pelarutan emas; roasting; tiosianat

Upaya Nilai Tambah Sludge Scale Sebagai Bahan Baku Pelet Bijih Pelet Soesaptri Oediyani; Anistasia Milandia; Maya Saputri
Jurnal Furnace Vol 4, No 2 (2021): NOVEMBER 2021
Publisher : Department of Metallurgical Engineering, Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar

Limbah baja semula termasuk ke dalam limbah B3 tetapi berdasarkan Peraturan Pemerintah No. 22 tahun 2021 tentang Penyelenggaraan Perlindungan dan Pengelolaan Lingkungan Hidup Lampiran XIV limbah industry besi dan baja dikategorikan sebagai Limbah Non-B3. Sludge scale adalah salah satu limbah proses pembuatan baja yang belum dimanfaatkan sehingga perlu diberikan nilai tambah mengingat masih mengandung besi dalam jumlah besar sebagai contoh sludge scale BOF dalam keadaan kering mengandung 50 – 60% Fe. Salah satu upaya pemanfaatan sludge scale adalah pembuatan pelet besi menggunakan bahan baku sludge scale. Pada penelitian ini dilakukan pengamatan nilai kuat tekan, porositas dan reducibility pelet dengan menggunakan variasi binder yaitu bentonit, molase dan dekstrin dengan komposisi masing-masing 0,5 , 2,5 dan 5%. Temperatur firing yang digunakan yaitu 1200 dan 1300oC. Hasil penelitian menghasilkan kuat tekan tertinggi pada 5% bentonit sebesar 2000N/pelet, porositas dan reducibility tertinggi pada 0,5 % molase masing-masing sebesar 48,67% dan 8,82% reduksi per menit.

PENGARUH WAKTU REDUKSI DAN KOMPOSISI PELET TERHADAP PERSEN Fe METAL DAN PERSEN Ni FeNi SPONS DARI BIJIH NIKEL LIMONIT MENGGUNAKAN SIMULATOR ROTARY KILN [The Influence Of Reduction Time And Pellet Composition On Fe And Ni Metal Percentage Of Feni Sponge From Limonite Ore Reduced By Using Rotary Kiln Simulator] Yopy Henpristian; Iwan Dwi Antoro; Soesaptri Oediyani
Metalurgi Vol 29, No 3 (2014): Metalurgi Vol.29 NO.3 Desember 2014
Publisher : National Research and Innovation Agency (BRIN)

Pengaruh Rapat Arus dan Waktu Pelapisan Nikel pada AISI 410 dengan Metode Pulse Electrodeposition terhadap Strukturmikro dan Laju Korosi [The Influences of Current Density and Time on Microstructure and Corrosion Rate Nickel Coating in Aisi 410 by Pulse Electro Deposition Method] Rivaldo Ramadhana Saputra; Soesaptri Oediyani; Yulinda Lestari; Efendi Mabruri
Metalurgi Vol 32, No 2 (2017): Metalurgi Vol. 32 No. 2 Agustus 2017
Publisher : National Research and Innovation Agency (BRIN)

Nickel plating process with pulse methods in AISI 410 electrodepostion has been done to reduce corrosion rate of this material in industrial applications i.e turbine blade that is often experienced corrosion problems. The coating process using nickel sulfate 250 g / l, boric acid 50 g / l and nickel chloride 45 g / l at temperature of 50-60 ° C with various of current densities for 10, 15, 20 and 25 A / dm² and time for coating process of 10, 15 and 20 minutes. Duty cylce used was 80% and the pulse frequency approximately around 100 Hz. Microstructure examined by using SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) to observe grain size and thickness of the nickel layer. Corrosion rate measured by using CMS (corrosion measurement system). The results showed that increasing of current density and coating process would reduce grain size and corrosion rate in coating area. The corrosion rate is 0.00027 mmpy when the current density is 25 A / dm² and plating time is 20 minutes. AbstrakProses pelapisan nikel dengan metode pulse electrodepostion pada AISI 410 dilakukan untuk menurunkan laju korosi AISI 410 pada aplikasi industri, yaitu turbin blade yang sering mengalami masalah korosi. Proses pelapisan menggunakan larutan nickel sulphate 250 g/l, boric acid 50 g/l dan nickel chloride 45 g/l pada temperatur 50 – 60°C dengan variasi rapat arus 10, 15, 20 dan 25 A/dm² dan lamanya proses pelapisan 10, 15 dan 20 menit. Duty cylce yang digunakan adalah 80% dan frekuensi pulse 100 Hz. Pengujian struktur mikro dilakukan menggunakan SEM-EDAX untuk melihat ukuran butir dan ketebalan lapisan nikel yang terbentuk. Pengujian laju korosi dilakukan menggunakan alat CMS. Hasil penelitian menunjukkan bahwa semakin besar rapat arus dan semakin lama proses pelapisan maka ukuran butir yang tergambarkan dalam mikrostruktur lapisan semakin kecil dan laju korosi yang terukur semakin kecil. Laju korosi paling kecil adalah 0,00027 mmpy pada rapat arus 25 A/dm² dan waktu pelapisan 20 menit.

The Effect of Voltage and Time In Synthesis Manganese Dioxide from Manganese Sulfate Precursor Eka Fitri Wulandari; Lia Andriyah; Soesaptri Oediyani; Latifa hanum Lalasari; Tri Arini; Nadia Chrisayu Natasha; Fariza Eka Yunita; Ariyo Suharyanto; Eko Sulistiyono
Metalurgi Vol 37, No 1 (2022): Metalurgi Vol. 37 No. 1 April 2022
Publisher : National Research and Innovation Agency (BRIN)

The utilization of manganese dioxide (MnO2) as a cathode material for lithium-ion battery has attract many attentions because of their excellent electrochemical properties which have high theoretical storage capacity of 615 mAh/g. In this study, synthesis of MnO2 was carried out from manganese sulfate (MnSO4) precursor which is a pregnant leach solution from the leaching process of manganese ore from Trenggalek Regency. The electrolysis method has been used in this synthesis of MnO2 in an electrochemical cell consisting of two graphite electrodes with dimensions (16 x 5 x 0,3) cm. The purpose of this study is to determine the effect of voltage and time to particles amount of MnO2, to determine the phase and crystal structure of MnO2 and its morphological microstructure. The electrolysis process was carried out in 2000 ml of MnSO4 solution under constant stirring at 60oC with DC voltage varied by 2, 4, 6 and 8 volt and time varied by 4, 8, 12 and 16 hours. The precipitates formed at anode were separated, then the particles were dried at 110oC for 2 hours. The main contain of MnO2 were analyzed by X-Ray Fluorescence (XRF), the phase and crystal structure were evaluated by X-Ray Diffraction (XRD) and the morphological microstructure were captured by Scanning Electron Microscope (SEM). The results revealed that the highest particles amount of MnO2 is 31,63 grams which is electrolyzed at 8 volts for 16 hours. The highest purity of MnO2 is 89,23% which is electrolyzed at 2 volts for 16 hours. The particles produced were α-MnO2 with a tetragonal crystal system and nearly spherical in shape with size particles ranged from 136,01-202,48 and 144-352 nm.

Pengaruh Penambahan Inhibitor Ekstrak Tembakau Terhadap Laju Korosi Internal Pipa API 5L X-52 Pada Artificial Brine Water Dengan Injeksi Gas CO2 [Effect of Addition of Extracted Tobacco Inhibitor to The Corrosion Rate of Internal Steel Pipe API 5L X-52 in Artificial Brine Water With CO2 Gas Injection] Rapli Nur Ahmadi; Soesaptri Oediyani; Gadang Priyotomo
Metalurgi Vol 31, No 3 (2016): Metalurgi Vol. 31 No. 3 Desember 2016
Publisher : National Research and Innovation Agency (BRIN)

Crude oil containing brine water with high concentration of NaCl and HCO3 and the presence of dissolved CO2 gas may increase the potential for corrosion in the pipeline. The use of natural corrosion inhibitor is one of the alternative to solve these problem. Natural materials were chosen as an alternative because it is safe, readily available, biodegradable, low cost, and environmentally friendly. This study was conducted to determine the effect of tobacco extracts on the rate of corrosion and inhibition efficiency. The novelty of this research is a continuous injection of CO2 gas that does not exist in previous research. Spectroscopy analysis was conducted to determine the chemical composition of samples of steel API 5L X-52, TLC densitometry was used to determine the levels of nicotine in tobacco sauce. Gamry Potensiostat Type 6:25 was used for testing the corrosion behavior, using the Tafel polarization and EIS methods. The results show that, the corrosion rate of samples decreased with the addition of tobacco extracts. The addition of 60 ppm of tobacco extract in a solution decrease corrosion rate samples at 8.95 mpy in ABW 1 and 9.87 mpy in ABW 2. Optimum inhibition efficiency occurs upon the addition of 60 ppm tobacco extracts, for the solution of ABW 1 by 79.51% and amounted to 80.94% ABW 2. The inhibition efficiency began to decline by the addition of 80 ppm, to 42.32% in ABW 1 by and 68.71% in ABW 2.AbstrakCrude oil yang mengandung brine water dengan kadar NaCl dan HCO3 - yang tinggi serta adanya gas CO2 yang terlarut dapat meningkatkan potensi korosi pada pipa. Penggunaan inhibitor korosi alami menjadi alternatif baru untuk menyelesaikan masalah tersebut. Bahan alam dipilih sebagai alternatif karena bersifat aman, mudah didapatkan, bersifat biodegradable, biaya murah, dan ramah lingkungan. Penelitian ini dilakukan untuk mengetahui pengaruh penambahan ekstrak tembakau terhadap laju korosi dan efisiensi inhibisi yang dihasilkan dengan menambahkan pembaharuan penelitian berupa penginjeksian gas CO2 secara kontinu yang belum ada pada penelitian sebelumnya. Pengujian pada penelitian ini menggunakan spectroscopy untuk mengetahui komposisi kimia sampel baja API 5L X-52, TLC. Densitometri digunakan untuk mengetahui kadar nikotin pada sampel tembakau. Gamry Potensiostat Type 6.25 digunakan untuk pengujian polarisasi Tafel dan EIS. Hasil penelitian menunjukkan bahwa data laju korosi baja API 5L X-52 mengalami penurunan dengan penambahan ekstrak tembakau. Penurunan optimum laju korosi terjadi pada penambahan 60 ppm ekstrak tembakau pada larutan ABW 1 sebesar 8,95 mpy dan ABW 2 sebesar 9,87 mpy. Peningkatan optimum efisiensi inhibisi terjadi pada penambahan 60 ppm ekstrak tembakau, untuk larutan ABW 1 sebesar 79,51% dan ABW 2 sebesar 80,94%. Efisiensi inhibisi mulai mengalami penurunan kembali pada penambahan 80 ppm, untuk larutan ABW 1 sebesar 42,32% dan ABW 2 sebesar 68,71%.

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