MINERAL

POTENSI LOGAM TANAH JARANG DI DALAM ABU BATUBARA

Diana Purbasari — 2023-12-08

Coal is a fossil fuel that is still used as fuel for Steam Power Plants (PLTU). The greater the demand for electrical energy, the greater the need for coal to meet the fuel needs of the PLTU. The combustion of PLTU produces combustion residue in the form of fly ash and solid ash. Fly ash has its own problem level compared to solid ash. The issue of air pollution, sources of disease and radioactive pollutants are the negative impacts of fly ash left over from burning coal. Coal ash is formed from compounds that do not burn in the coal combustion process including the presence of rare earth metals (LTJ). LTJ is a valuable element which in certain levels can be processed into valuable goods. Separation of LTJ in coal can reduce the ash content and improve the quality of coal, so it is necessary to know the potential of LTJ contained in coal ash. The coal sample tested was coal from PT Bukit Asam Tanjung Enim Mining Unit. Identification of LTJ elements in the ash at the PLTU using XRD, ICP and SEM analysis. There is element Cerium (Ce) 55.3 ppm in fly ash and 22.6 ppm in bottom ash, element yttrium (Y) 36 ppm in fly ash and 10.7 ppm in bottom ash, element Lanthanum (La) 27.3 ppm on fly ash and 10.5 ppm on bottom ash. Neodymium (Nd) 26.1 ppm in fly ash and 6.9 ppm in bottom ash. Finally, there is an element of Samarium (Sm) 1.4 ppm in fly ash and 0.7 ppm in bottom ash. There is a promising potential for rare earths in coal ash, but for levels below 500 ppm it is still not feasible to manage, so it is necessary to enrich the rare earths first.

Analisis Kuat Tekan Dan Penyerapan Air Menggunakan Pasir Tailing Timah Dan Kaolin

Ummi Athiyyah Zikri — 2024-01-22

The environmental damage resulting from mining not only eliminates soil fertility but changes the landscape of the existing ecosystem and produces waste such as tailings and kaolin and understory. The results of tin and kaolin tailings mining have not been utilized optimally. This research aims to analyze the effect of using tin tailings sand and kaolin on bricks which produces compressive strength and water absorption in accordance with standards. The method used is to take tin and kaolin tailings mixed with clay with a predetermined composition and tested in the laboratory. Based on the test results, the compressive strength value obtained meets the standards, namely the percentage of 15% tin tailings sand and 10% kaolin, the compressive strength value is 5,150 Mpa. The water absorption value using percentages of 5%, 10% and 15% tin tailings sand and 10% kaolin has met the specified standards.

Evaluasi Kinerja Alat Pengolahan Wet Belt Low Intensity Magnetic Separator (WBLIMS) Untuk Meningkatkan Kadar dan Recovery Sn di TB Primer Batubesi PT Timah Tbk Kabupaten Belitung Timur

Dimas Pangestu — 2024-04-25

Primary TB Batubesi Site a subsidiary of PT Timah Tbk, processes primary tin feed stockpile and SHP of oxide clay type using various tools, including the Wet Belt Low Intensity Magnetic Separator (WBLIMS). Currently, WBLIMS can only produce tin concentrate with a grade of 0.5-2% and a recovery of 5-8%, falling below the company's target of 8% grade and 15% recovery (XRF Test). This research conducted eight experiments with variations in feed types and rates. The WBLIMS feed from the stockpile has a Sn content of 0.62%, resulting in a tin concentrate with 1.21% Sn and a recovery of 7.05%. On the other hand, the feed from SHP has a Sn content of 0.61%, resulting in a tin concentrate with 0.95% Sn and a recovery of 5.11%. The type and rate of feed affect the increase in Sn grade and recovery. At low feed rates, the feed material yields lower Sn grade and recovery, while at high feed rates, the results are higher. Increasing the feed rate for WBLIMS from the stockpile leads to a decrease in Sn grade and recovery, whereas in the processing of SHP, the Sn grade increases but recovery varies. Experiments F1L1 and F2L3 yield the most optimal Sn grade and recovery, with F1L1 having a Sn grade of 2.28% and recovery of 11.54%, and F2L3 having a Sn grade of 2.87% and recovery of 9.24%. Although not reaching the company's target, these experimental results can enhance the Sn grade and recovery compared to the previous setup.

Interpretasi Material Pada Rancang Bak Ukur Skala Laboratorium Dengan Pendekatan Konfigurasi Wenner, Wenner – Schlumberger dan Dipole-dipole

Guskarnali Guskarnali — 2024-05-02

Geoelectric measurements have been carried out using multichannel ResistivityMeter (Geores) tools with Wenner, Wenner-Schlumberger, and Dipole-dipole Configuration approaches on the influence of materials arranged in a laboratory-scale measuring tub design with dimensions of 194x184x80 cm. The measured method is the variation in resistivity value against each trajectory of the material. The method used is the variation of resistivity values for each path of the material that has been arranged in a laboratory scale measuring design. Geoelectric measurements were carried out on 7 lines (5 line in the West-East direction and 2 line in the North-South direction). The spacing between the electrodes of each line is 10 cm with 16 electrodes in one line so that each line has a length of 160 cm or 1.6 m which corresponds to the length and width dimensions of a laboratory scale measuring design. The electrode arrangement parameters are constant with respect to changes in the configuration selected from the geores parameters during geoelectric measurements. The measurement results showed that the identified depth reached 31.2 cm. The low resistivity value category has an interval of 374-4,397 ohm.meters at a depth of 0-12.5 cm, which is the influence of building sand material containing water and soil, while the depth interval is 12.5 - 31.2 cm ohm.meters (material category that is influenced by 2 iron rods, tin tailings sand, granite, gravel) with resistivity values ranging from 12,378–67,498 ohm.meters. From experiments on the influence of the resistivity values of the three Wenner, Wenner-Schlumberger, and Dipole-dipole configurations, it was obtained that the smallest absolute error resistivity value in the Wenner configuration was 5.01% against the overall average absolute error resistivity value of 10.16%.