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POTENSI DEPOSIT WOLFRAM DI INDONESIA: STUDI KASUS TOBOALI - BANGKA SELATAN Imelda Eva Roturena Hutabarat; Sabtanto Suprapto; Priatna Priatna; Maryono Maryono; Rudiyansah Rudiyansah
Jurnal Teknologi Mineral dan Batubara Vol 19 No 2 (2023): Jurnal Teknologi Mineral dan Batubara Edisi Mei 2023
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/jtmb.Vol19.No2.2023.1478

Abstract

Bangka island is one of the islands in the Southeast Asian Tin Belt that makes Indonesia the largest tin (Sn) producer in the world. The carrier of wolframite is a by product mineral of the mineral tin (cassiterite). This study aims to study the presence and type of wolfram-as by product in the tin deposits on Bangka island. The research area was conducted on the eastern edge of Klabat Granite in Kepoh Village, Toboali District, South Bangka, at coordinates of 106o 31' 58" BT, 2o 56' 56 " LS. The result shows the presence of wolfram with grade of wolfram in veins reaching 8287 ppm. Wolfram was identified as an associated mineral in the tin mineralization system in Toboali along with rare earth metals (LTJ), molybdenum (Mo) and platinum (Pt). The results of analytical studies (UV, XRF, ICP OES, mineragraphy) on Toboali area minerals show the presence of wolfram in ores, concentrates, slag, and floor crusts. The identified wolfram minerals are wolframite (Fe.Mn)WO4 and scheelite (CaWO4) which are characterized through differences in properties such as color, fluorosence, magnetic, specific gravity and hardness values. The results obtained showed the presence of wolfram in Toboali area with wolfram content of 742 ppm in ore and also in the tin process, specifically in slag II of 1.02%. In addition, wolfram is indicated on the furnace floor and on the anode slime. Indonesia as one of the countries that owns wolfram minerals needs to continue the wolfram extraction process so that Indonesia receive the added value from its minerals.
Sintesis Dan Karakterisasi Material Katoda LiMn0,7Fe0,3-xNixPO4/C Dengan 0 ≤ X ≤ 0,2 Dalam Aplikasi Baterai Litium-Ion Rudiyansah, Rudiyansah; S, Anne Zulfia; Prihandoko, Bambang
JURNAL ELTEK Vol. 21 No. 2 (2023): Oktober 2023
Publisher : Politeknik Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33795/eltek.v21i2.4393

Abstract

Pati singkong sebagai karbon pelapis bahan aktif LiMnPO4, Fe dan Ni (covalent-doping) ditempuh untuk meningkatkan konduktifitas elektronik-ionik, nilai specific capacity dan working voltage. Proses solid state reaction berupa ball milling (330 rpm, 48 jam) dan sintering (800°C, 2 jam) digunakan dalam pembuatan bahan aktif. Pola difraksi LiMnPO4 terlihat pada uji XRD pada bahan aktif. Bahan aktif terlapisi karbon berukuran 290 nm dan ukuran kristalit 60 nm terbentuk melalui proses Ball Milling. Pengujian SEM memperlihatkan pertumbuhan pelapisan karbon kearah horizontal dan pengujian EDX menunjukkan kadar Mn yang tinggi mengkonfirmasi peran pati singkong sebagai fasilitator pengintian pelapisan karbon. Nilai vibrasi v1 - v4 (1138 dan 1098 cm-1) hasil pengujian FTIR menunjukkan polianion  terbentuk. Pelapisan karbon memberikan nilai konduktifitas elektronik-ionik sebesar 1 x 10-3 S/cm dan 7,2 S/cm, peningkatan nilai konduktifitas elektronik terjadi akibat penambahan Ni. LiMn0,7Fe0,25Ni0,05PO4/C memberikan nilai specific capacity oksidasi 60,92 mAh/gr dan nilai Voks-red sekitar 4,13 Volt dan secara praktikal dapat digunakan sebagai bahan aktif katoda baterai Li-Ion. ABSTRACT Carbon-coating process with starch of cassava in LiMnPO4 active material, co-subtitution by adding Fe and Ni have been used to enhance ionic-electronic conductivity, specific capacity, and working voltage. Pattern diffraction of XRD shown LiMnPO4 structure have been formed via milling process (330 rpm, 48 hours) and sintering process (800°C, 2 hours) as called as solid state reaction. Ball Milling produced active material with the particle size and crystallite size up to 290 nm and 60 nm respectively. Carbon-coating have been grown in horizontal direction in cathode material become an evidence that the starch of cassava have been facilitates nuclea of carbon-coating to grown in cathode material and can be seen by SEM, and also the high content of Mn that have founded by EDX evaluation agreed. Polyanion  have formed and indicated by vibration value of v1 - v4 (1138 and 1098 cm-1) during FTIR evaluation. Electronic conductivity increased up to 1 x 10-3 S/cm by carbon-adding process, and Ni-addition as cation-doping contributed also. LiMn0.7Fe0,25Ni0.05PO4/C of cathode material shown the highest specific capacity oxidation near 60.92 mAh/gr and Voxidation/reduction around 4.13 Volts and practically can be used as Li-Ion battery.