ABSTRAK
Bijih nikel laterit banyak tersedia di Indonesia bagian timur, seperti PulauSulawesi dan kepulauan Maluku termasuk pulau-pulau kecil di sekitarnya.Faktanya, sejauh ini bijih nikel kadar rendah tipe limonit belum diproses karenakandungan nikelnya sangat rendah. Dalam tesis ini kami membahas hasil terbarupada efek scale-up dari pengolahan bijih nikel kadar rendah melalui pendekatanhidrometalurgi. Proses ini dipilih karena kandungan magnesium yang rendahdalam bijih dan konsumsi energi yang minimal selama pemprosesan. Proses yangdipilih yaitu pelindian atmosferik. Variabel-variabel proses yang dipelajari adalahpersen 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 menggunakanAAS untuk menentukan fraksi elemen terlarut. Hasil penelitian saat inimenunjukkan bahwa pelindian bijih nikel kadar rendah jalur hidrometalurgimenggunakan 37% asam klorida pekat telah mengekstraksi Ni dan Fe dari bijihdengan 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 penurunanhingga sekitar 45% ketika bahan baku ditingkatkan dua kali lipat menjadi 200gram limonit.
Abstract
The laterite nickel ores are abundantly available in the eastern part of Indonesiaisland like Sulawesi and Maluku islands including many small islands aroundthem. The fact that nickel ores called limonite have not been processed so far dueto the nickel content is very low. In this thesis, we discussed our recent works onthe effects of scaling up of processing for low grade nickel ores through ahydrometallurgical approach. This was selected due to the low magnesiumcontent in the ores and minimum energy consumption during processing. Theselected process is the atmospheric leaching. Processing variables which werestudied including the optimum percentage of solvent, processing temperatures,leaching time, mesh sizing and the scale-up effects. Characterization of theresidue was studied using SEM, XRD and XRF. While the materials whichdeposited in the leaching filtrate were analyzed using AAS to determine thefraction of dissolved elements. Results of current recearch work showed thatleaching of low grade nickel ore using a hydrometallurgical route using 37%concentrated hydrochloric acids have resulted extracted materials of Ni and Fewith extraction yields 76.7% and 75.8% respectivelly. This was obtained at thefollowing processing conditions: optimum temperature 90°C; 200 mesh and thestirring speed of 300 rpm. Further to this, when the feedstock was scaled up to100 grams limonite, the yields were decreased to 55 % and 65 % for Ni and Ferespectively. A further decreased to about 45 % occurred when the feedstock wasdoubled to 200 grams limonite. |
