Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
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EKSTRAKSI EMAS DARI LUMPUR ANODA MELALUI PROSES KLORINASI BASAH DAN EKSTRAKSI PELARUT
No full textPercobaan mengekstraksi emas dilakukan secara selektif dari residu pelindian timbal dalam lumpur anoda melalui proses klorinasi basah, diikuti proses ekstraksi pelarut menggunakan ekstraktan pelarut organik dibutyl carbitol (DBC). Hasilnya menunjukkan bahwa pemberaian emas oleh pelindi HCl atau gas Cl2 yang dibantu oksidator H2O2 ternyata sangat efektif, bahkan menjadi lebih efektif jika menggunakan peralatan pelindian yang kedap gas. Berikutnya, proses ekstraksi pelarut terhadap larutan mengandung emas hasil klorinasi menunjukkan terbentuknya larutan organo-emas (loaded DBC) meningkat dengan meningkatnya konsentrasi DBC hingga 40% (v/v) dengan lama waktu pengadukan yang singkat, persen ekstraksi emas yang diperoleh adalah 99,31%. Akhirnya, loaded DBC direduksi untuk menghasilkan logam emas
PENGARUH PENAMBAHAN SENYAWA ALKALI UNTUK PEMBUATAN NUGGET FERONIKEL DALAM TUNGKU PUTAR
No full textPembuatan logam paduan feronikel pada umumnya melalui jalur tungku putar - tungku busur listrik yang membutuhkan energi (suhu 1300 - 1400°C ) dan investasi besar pada skala produksi yang juga besar, karena itu diperlukan penelitian pembuatan nugget feronikel melalui proses reduksi semi-solid selektif menggunakan tungku putar pada suhu lebih rendah agar dapat diterapkan pada skala kecil. Agar suhu semi-solid reduksinya dapat diturunkan, maka dicoba penambahan senyawa alkali (natrium klorida, natrium karbonat dan kapur) ke dalam proses pada suhu 1150°C selama 4 jam. Penam- bahan 5% NaCl menghasilkan nugget FeNi berkadar sekitar 11% Ni dengan perolehan nikel sebesar 72%. Penambahan Na2CO3 ke dalam proses reduksi berbasis 1% NaCl dan 1% kapur memengaruhi penurunan tingkat segregasi Ni
ANALYSIS OF REGIONAL REGULATION ON GENERAL MINING SECTOR (MINERAL AND COAL)
No full textAs Law No. 22 Year 1999 on Regional Government was implemented and then renewed by Law No. 32 Year 2004 on the same subject, all autonomous areas have issued various regional regulations, including that on general mining (mineral and coal). This is in line with the requirement of all autonomous areas for authority in managing their own regions based on the autonomy principles. After one decade since the regulation was applied, evaluation conducted by the government revealed that regional regulation in the general mining sector oriented mostly on increasing regional revenue without taking into consideration the existing legal principles. Surveys on 8 provinces showed similar facts, and the condition led to an unconducive business climate that could hinder the economic growth and the regions’ investment opportunity
EXTRACTION OF ALUMINA FROM BAUXITE RESIDUE FOR PREPARATION OF ALUMS AND POLY ALUMINUM CHLORIDE
No full textThe chemical composition of West Kalimantan bauxite is 45 pct Al2O3 and 16 pct Fe2O3 that has been extracted to produce alumina and bauxite residue (red mud). The residues contains Al2O3 20 pct and Fe2O3 about 37 pct, wich was furthermore processed by roasting or lime-soda sinterization at temperature of 800- 1100°C. The sintered product was leached with sodium carbonate solution to produce soluble sodium aluminate (2NaAlO2). The solution obtained was then precipitated to produce hydrated alumina (Al(OH)3. Hydrated alumina was then sulfateized by adding ammonium hydroxide, and followed by crystallization to produce high purity of ammonium aluminum sulfate crystals (alums). In addition, hydrated alumina was also chlorinated in stoichiometric amount at mol ratio of OH/Al = 0.5 – 1.5 to form polyaluminum chloride (PAC). The residue obtained from leaching was concentrated by 1000 gauss of magnetic separator to produce iron concentrate as a by product. As the results, sulfatation of hydrated alumina with addition of ammonium hydroxide results high grade of ammonium aluminum sulfate (NH4Al(SO4)2 .12H2O) crystals. Chlorination of hydrated alumina in stoichiometric amount at mol ratio of OH/Al = 1.0 results polyaluminum chloride (PAC) that quality is adjacent to the first type of PAC. Through the soda-lime sinter process, it can also produce iron concentrate having grade of 66 % Fe2O3 with 40 % of recover