Suchergebnisse

Dua sumber LTJ berasal dari mineral seperti monasit dan senotim. Ketersediaan LTJ di kerak bumi relatif sedikit, tersebar dan jarang terjadi dalam bentuk bijih. Dalam penelitian ini bahan baku yang digunakan adalah campuran konsentrat LTJ yang berasal dari PT. Monokem Surya. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh konsentrasi H2C2O4, kecepatan pengadukan dan suhu terhadap kemurnian dan pemungutan LTJ dari campuran konsentrat LTJ. Percobaan dilakukan dalam lima langkah: (1) Fusi alkali, proses dilakukan selama 3 jam pada suhu 450oC, dengan rasio padatan NaOH terhadap campuran konsentrat LTJ sebesar 1:1, untuk memutuskan ikatan fosfat; (2) ) Pelindian fosfat dalam produk fusi alkali menggunakan aquadest pada suhu 80oC; (3) Residu pelindian aquadest dilakukan proses perlindian menggunakan 6 M HCl selama 2 jam untuk melarutkan LTJ pada 90oC; (4) Menghilangkan kotoran seperti uranium dan thorium dengan mengendapkannya menggunakan NH4OH pada pH 1; (5) Presipitasi LTJ dari filtrat yang dihasilkan dari butir (4) menggunakan H2C2O4. Didapatkan hasil LTJ dengan kemurnian 96% dan pemungutan sebesar 95% pada konsentrasi H2C2O4 8,11%, kecepatan putar pengaduk 500 rpm, dan suhu 70oC.Two sources of REEs are from mineral monazite and xenotime. The availability of REEs is relatively abundant in the earth's crust, typically dispersed, and rarely occur in ores. In this study as raw material was a mixed rare earth concentrate from Monokem Surya Ltd. The purposes of this research were to determine the effect of concentration H2C2O4, stirring speed, and temperature regarding to purity and recovery REEs from the mixed rare earth concentrate. The experiments were conducted in five steps:(1) Alkaline fusion, the process was performed about 3 hours at 450oC, with ratio of NaOH solid to the mixed rare earth concentrate sand was 1:1, in order to break phosphate bonds;(2) Leaching of phosphate in alkaline fusion product using aquadest at 80 oC; (3) Aquadest leaching residue was leached using 6 M HCl for 2 hours to dissolve REEs at 90 oC; (4) Removal of impurities such as uranium and thorium by precipitating them using NH4OH at pH 1; (5) Precipitation of REEs from filtrate produced from point (4) using H2C2O4. The results of REEs with 96% purity and 95% recovery was obtained at concentration H2C2O4 8,11%, stirring speed 500 rpm, and temperature 70oC.

Community participation in mangrove forest ecosystem conservation is an effort to overcome and avoid mangrove ecosystem deterioration. The findings show that mangrove forests in Kampung Laut's coastal region, particularly in the village of Ujung Alang, are still well preserveddue to diverse mangrove planting efforts. Currently, the community uses mangrove plants by converting some plant sections into food and using the plant's stems as building materials. Efforts have been made to preserve mangrove forest ecosystems through the Sustainable Utilization of Mangrove Forests for the Production of Natural Dyes with a Zero Waste System. The following are the activities: 1) Dissemination of the concept to raise public awareness of the potential of mangrove plants as a source of raw materials for natural dyes to increase community income and sustainably manage mangrove forests; 2) Raising the awareness of the younger generation to improve the local economy through the development of micro-scale SMEs in the field of mangrove-based natural dyes; and 3) Technical training on thinning/logging and sustainable mangrove planting to acquaint participants with the concepts of thinning/logging and sustainable man Establish the program's purpose, which should be divided into six activities. Many farmer groups anticipate that this community service under the auspices of Krida Wana Lestari will assist them in improving their existing products and estimating the potential process of their natural mangroves. This program raises public awareness of the mangrove plant's potential as a source of raw materials for natural colours. In addition, this activity enables the community to do technical logging and sustainable mangrove planting to support the availability of raw materials for natural dyes. Consequently, the creation and development of a local economic business unit with a green entrepreneurship incubator model based on mangrove conservation and zero waste from natural dye SMEs have begun.

AbstrakKebutuhan ekstraksi nikel dari bijih nikel laterit khususnya jenis bijih limonit dengan kadar nikel yang rendah sangat diperlukan karena kebutuhan nikel yang terus meningkat dengan adanya pengembangan kendaraan bermotor listrik berbasis baterai. Jenis dan karakteristik bijih laterit yang berbeda akan memberikan pengaruh pada hasil ekstraksi nikel. Pada penelitian ini dilakukan ekstraksi nikel dari bijih laterit jenis limonit yang berasal dari Pulau Halmahera (LH)) dan Pulau Sulawesi (LS) menggunakan pelindian atmosferik. Asam sulfat digunakan sebagai agen pelindian. Penelitian dilakukan untuk mengetahui pengaruh karakteristik bijih limonit (LH dan LS) pada berbagai variabel pelindian yaitu suhu (30oC, 50oC dan 80oC), konsentrasi asam sulfat (0,5M; 1M; dan 2M), waktu pelindian (15, 30, 60, 120, dan 240 menit), serta rasio bijih terhadap reagen pelindian (5, 10, dan 20% w/v) terhadap ekstraksi nikel dari bijih limonit. Hasil penelitian menunjukkan bahwa karakteristik bijih laterit sangat berpengaruh pada hasil pelindian dan persen rekoveri nikel. Nikel dari bijih LH yaitu jenis limonit dari Pulau Halmahera dapat diekstrak secara maksimal (100%) pada konsentrasi asam sulfat 0,5M, suhu 80oC, rasio bijih/larutan asam sulfat 10%, dan waktu pelindian 2 jam. Sedangkan persen ekstraksi nikel dari bijih LS yang terbesar adalah 95% yang diperoleh pada konsentrasi asam sulfat 2M, suhu 80oC, rasio bijih/larutan asam sulfat 5%, dan waktu pelindian 4 jam. AbstractNickel extraction from nickel laterite ores particularly low-grade limonite ore is needed along with the increase of nickel consumption on the development of battery electric vehicle. Types and characteristics of nickel laterite ores affect greatly on the nickel extraction from these ores. This research conducted the extraction of nickel from limonite ore from different areas i.e. Halmahera Island (LH) and Sulawesi Island (LS) using atmosferic leaching. Sulfuric acid (1M) was used as leaching reagent. Leaching processes were carried out for investigating the effects of limonite ore characteristics (LH and LS), leaching temperatures (30oC, 50oC dan 80oC), concentration of sulfuric acid (0.5M; 1M; 2M), leaching time (15, 30, 60, 120, and 240 minutes), and ratio of ore amount to volume of leaching reagent on the nickel extraction from limonite ores. Experimental results showed that ore characteristic affected greatly on the leaching result and nickel leaching recovery. Nickel from LH ore could be extracted maximum (100%) using sulfuric acid 0.5M, temperature of 80oC, and leaching time 120 minutes (2 hours). Whereas, the highest nickel extraction percentage from LS ore is 95% using sulfuric acid 2M, temperature of 80oC, and leaching time 240 minutes (4 hours).

Salah satu sumber daya mineral yang berperan penting dalam kehidupan masyarakat di dunia adalah timah. Sumber daya timah dapat diolah menjadi timah sulfat yang memiliki nilai jual dan manfaat yang lebih tinggi. Timah(II) sulfat digunakan dalam aplikasi industri dan manufaktur sebagai agen elektroplating dan produk perawatan permukaan logam. Permintaan timah sulfat di pasar global mengalami peningkatan yang signifikan. Beberapa metode produksi timah sulfat telah dikembangkan untuk meningkatkan kualitas sumber daya timah. Tujuan utama dari penelitian ini adalah untuk mengolah sumber daya timah dengan metode yang efektif dan ramah lingkungan yang terkait sintesis timah(II) sulfat dengan metode elektrolisis. Hasil penelitian menyimpulkan bahwa konsentrasi larutan elektrolit dan tegangan operasi sangat mempengaruhi sintesis timah(II) sulfat. Namun, variabel ini dibatasi oleh luas permukaan yang terbatas. Kondisi terbaik penelitian terjadi pada tegangan operasi 0,6V dan larutan elektrolit dengan konsentrasi 0,05 M.

The increasing need of REY has been observed in industries such as catalyst industry, metallurgy, military, health and renewable energy resources. REY such as Ce, Nd, Y, and Eu has a prominent evidence to improve material properties such as high electropositive, good conductivity and renewable energy. Due to this increasing need of REY, exploration of alternative source has been conducted. One of the promising alternative sources is coal fly ash. The conventional method to recover REY from coal fly ash using inorganic acids is harmful to the environment. Thus, the exploration of REY extraction from coal fly ash using organic acid has been proposed in this study. The leaching agent was acetic acid applied for all operating condition. Regarding to the mineralization of REY in the form of siliceous minerals (non-magnetic coal fly ash). Silicate digestion was conducted using sodium hydroxide 8 M with solid-to-liquid of 25% to decompose the siliceous mineral. Further, the REY bound siliceous mineral will change to REY(OH)3. Temperature as one of the operating conditions was varied. The maximum recovery of leaching 20.58 %, 43.53 %, 17.38%, 40.96 %, 18.45 % and 32.74 % were achieved for Ce, Dy, La, Nd, Y and Yb respectively at temperature of 90 0C pH 1.74 and 120 minutes. For some metals, increasing the temperature higher than 70 0C does not provide any significant effect for REY recovery such as La and Ce.