Agus Budi Prasetyo

Thermal characteristic of limonite ore upon calcination and reduction

Thermal characteristics of the limonite laterite ore types have been studied using TG / DTA. There are four endothermic peaks at 250, 646, 900, and 1023 °C with a total mass loss of 10.07wt%. These four peaks correspond to the XRD results on samples calcined at 600-1000 °C. Analysis of TG / DTA to the mixture of limonite and graphite showed two endothermic reaction peaks at 641 and 900 °C and an exothermic peak at 1180 °C. Reduction of the limonite-graphite mixture was done by heating at 800-1100 °C for 1 hour, and the reduced samples were analyzed using XRD. The results indicate that the reduction process proceed completely at higher temperatures, indicated by the increasing intensity of kamacite and Fe metal phase, and the decrease of peak intensity of carbon due to reaction with metal oxides. At 1100 °C, intensity of Fe-metal decreased due to sintering of Fe which may occur because the temperature was too high.

Effect of temperature in the selective reduction process of limonite nickel ore

Temperature is the main factor for the reduction process that influence to reduction degree, phase and morphology transformation. In order to determine these effects which is caused by reduction temperature, this study was conducted. Limoniticnickel ore was prepared by drying and size reduction. A part of prepared limonitewas characterized with XRF to determine the chemical composition. The other part was mixed with reducing agent and CaSO4 to produce pellet. A series of selective reduction processes were conducted to the pellet by using graphite crucible in the muffle furnace carbolite at 800° – 1100°C for 60 minutes. Reduced ore characterized by using XRD and SEM analysis. Based on the result study, weight loss and reduction degree increase as temperature raised along with CaSO4 addition. Moreover, it caused decomposition and transformation to the metallic phase of kamacite and iron up to 7.51% and 41.44% respectively in the reduction process at 1100°C for 60 minutes. Furthermore, particle size growth a...

Karakterisasi Pendahuluan Nikel Limonit Sulawesi

Indonesia merupakan negara yang mempunyai cadangan nikel laterit yang cukup besar. Bijih Nikel laterit merupakan salah satu sumber daya mineral yang melimpah di Indonesia. Cadangan bijih Nikel laterit di Indonesia mencapai 12% cadangan nikel dunia. Dalam bentuk cadangan, bijih nikel laterit Indonesia mencapai lebih dar 1.5 milyar ton. Cadangan tersebut tersebar di beberapa wilayah di Indonesia bagian timur yang diketahui mengandung jenis batuan ultra basic seperti di daerah Sulawesi Selatan dan tenggara dan beberapa pulau lainnya seperti Halmahera, Gebe, Obi, Gag, Waigeo dan Cycloop. Telah diketahui pula bahwa bagian terbesar dari cadabngan nikel laterit tersebut adalah bijih berkadar rendah dengan kandungan nikelnya sampai 1.8 %. Dari Hasil Analisis AAS didapatkan kandungan Besi (Fe) sebesar 58,95 sedangkan kandung Ni sebesar 1,26 % . Unsur lain yang terkandung dalam bijih nikel laterit kadar rendah yaitu Co dengan kadar 0,17%, Cr 0,47% dan Mg 4,08%. Dari hasil analisis SEM-EDX ini didapatkan kandungan unsur-unsur yang terdapat didalam bijih nikel laterit kadar rendah. Unsur-unsur Mayor dapat terdeteksi yaitu besi dan oksida. Unsur Fe yang paling dominan yaitu dengan kadar 39,06 %, sedangkan unsur oksida sebesar 26,46 %. Unsur-unsur minor yang terkandung yaitu Al dengan kadar 1,66 %, Si 3,37%, Ni 1,17%, Cu 1,87% dan Cr 0,45%. Prosiding Seminar Material Metalurgi. Hal. 135-141 ISSN 2085-0492

Study of lithium extraction from brine water, Bledug Kuwu, Indonesia by the precipitation series of oxalic acid and carbonate sodium

Lithium is one of the key elements in the development of batteries for electric car applications. Currently, the resources of the world’s lithium are derived from brine water and lithium mineral based on spodumene rock. Indonesia which is located in the area of the ring of fire, has potential brine water resources in some area, such as brine water from Bledug Kuwu, Central Java that used in this research. The purposes of this research are to characterize brine water, Bledug Kuwu and to investigate the influence of chemical solvents on Li, Na, K, Ca, Mg, Al, B ion precipitation from brine water. This research was done with 2 times the process of chemical precipitation that runs series as follows: 5 liters of brine water were chemically precipitated using 400 ml of 12.43 N oxalic acid and followed by chemical precipitation using 400 mL of 7.07 N sodium carbonate solutions. Evaporation and filtration processes were also done twice in an effort to separate white precipitate and filtrate. The filtrate was analyzed by ICP-OES and white precipitates (salts) were analyzed by SEM, XRD, and XRF. The result shows that oxalate precipitation process extracted 32.24% Al, 23.42% B, 22.43% Ca, 14.26% Fe, 3.21 % K, 9.86% Na and 14.26% Li, the following process by carbonate precipitation process extracted 98.86% Mg, 73% Ca, 22.53% Li, 82.04% Al, 14.38% B, 12.50% K, 2.27% Na. There is 63.21% lithium is not extracted from the series process. The SEM analysis shows that the structure of granules on the precipitated salts by oxalic acid form gentle cubic-shaped solid. In the other hand, oxalate precipitation followed by sodium carbonate has various particle sizes and the shape of crystals is fragments, prism and cube look like magnesium carbonate, calcium chloride, and calcite’s crystal respectively. This is in accordance with XRD analysis that phases of whewellite (CaC2O4.H2O), disodium oxalate (Na2C2O4), magnesite (MgCO3), calcium lithium aluminum (Al1.19 Ca1Li0.81), dolomite (CaCO3.MgCO3) appear in salt precipitated by oxalic acid. For salt precipitated by oxalic acid and sodium carbonate look peaks of dolomite and calcite (CaCO3) as main components. Lithium carbonate (Li2CO3) and calcium chloride (CaCl2) also are described with high peak intensity in this precipitation. A series of precipitation process shows that lithium is precipitated together with calcium, aluminum, and carbonate.Lithium is one of the key elements in the development of batteries for electric car applications. Currently, the resources of the world’s lithium are derived from brine water and lithium mineral based on spodumene rock. Indonesia which is located in the area of the ring of fire, has potential brine water resources in some area, such as brine water from Bledug Kuwu, Central Java that used in this research. The purposes of this research are to characterize brine water, Bledug Kuwu and to investigate the influence of chemical solvents on Li, Na, K, Ca, Mg, Al, B ion precipitation from brine water. This research was done with 2 times the process of chemical precipitation that runs series as follows: 5 liters of brine water were chemically precipitated using 400 ml of 12.43 N oxalic acid and followed by chemical precipitation using 400 mL of 7.07 N sodium carbonate solutions. Evaporation and filtration processes were also done twice in an effort to separate white precipitate and filtrate. The filtrate was anal...