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PEROLEHAN MINERAL BESI DARI RESIDU BAUKSIT INDONESIA Sariman; Rochani, Siti; Saleh, Nuryadi; Wijayanti, Retno; Dianawati, Erika Arum
Indonesian Mining Journal Vol 27 No 1 (2024): Indonesian Mining Journal, April 2024
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol27.No1.2024.1538

Abstract

Bauxite residue, a solid waste discharged during alumina extraction, is a hazardous material. Its disposal leads to a serious environmental issue although it contains valuable matter such as titanium, silica, rare earth elements, and high iron content (20-60%). This work aims to improve the recovery of iron content within the bauxite residue using three methods, namely direct magnetic separation, roasting followed by magnetic separation, and reduction followed by magnetic separation. Coal as a reductant and Na2CO3 and Na2SO3 as fluxes were used in the reduction process. The result of the study reveals that the direct magnetic separation produces iron concentrate with the Fe content of 53.69% and a recovery of 26.72%, while the roasting process at 900˚C and magnetic separation produces a concentrate of 54.57% Fe with a recovery of 37.33%. The best method was by reduction and magnetic separation process using 4% of Na2CO3  producing iron concentrates with a content of 63.53% Fe and recovery of 74.73%.
PEROLEHAN MINERAL BESI DARI RESIDU BAUKSIT INDONESIA Sariman; Rochani, Siti; Saleh, Nuryadi; Wijayanti, Retno; Dianawati, Erika Arum
Indonesian Mining Journal Vol 27 No 1 (2024): Indonesian Mining Journal, April 2024
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol27.No1.2024.1538

Abstract

Bauxite residue, a solid waste discharged during alumina extraction, is a hazardous material. Its disposal leads to a serious environmental issue although it contains valuable matter such as titanium, silica, rare earth elements, and high iron content (20-60%). This work aims to improve the recovery of iron content within the bauxite residue using three methods, namely direct magnetic separation, roasting followed by magnetic separation, and reduction followed by magnetic separation. Coal as a reductant and Na2CO3 and Na2SO3 as fluxes were used in the reduction process. The result of the study reveals that the direct magnetic separation produces iron concentrate with the Fe content of 53.69% and a recovery of 26.72%, while the roasting process at 900˚C and magnetic separation produces a concentrate of 54.57% Fe with a recovery of 37.33%. The best method was by reduction and magnetic separation process using 4% of Na2CO3  producing iron concentrates with a content of 63.53% Fe and recovery of 74.73%.
STUDI PERBANDINGAN PROSES PELINDIAN UNTUK EKSTRAKSI SKANDIUM DARI TERAK RESIDU BAUKSIT Sariman; Rochani, Siti; Saleh, Nuryadi; Rodliyah, Isyatun; Dianawati, Erika Arum; Wijayanti, Retno
Jurnal Teknologi Mineral dan Batubara Vol 19 No 3 (2023): Jurnal Teknologi Mineral dan Batubara Edisi September 2023
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/jtmb.Vol19.No3.2023.1509

Abstract

Scandium is classified as a rare earth element. Its existences are geochemically in small amounts as associate minerals. Consequently, scandium production is minimally from processing residues of major minerals. Indonesia has large bauxite deposits, and it is processed into alumina, producing bauxite residue as a by-product. The bauxite residue contains rare earth metals, including scandium. In this study, various ways of extracting scandium from bauxite residue slag were carried out. The bauxite residue beneficiation process was done through a smelting reduction process followed by magnetic separation. Scandium extractions were carried out from the bauxite residue slag through a leaching process with concentrated sulfuric, sulfation, alkali fusion, and a 2-stage acid leaching. The best percentage of scandium extracted was obtained at 88.40%, using the 2-stage acid leaching at the acid concentration of 500 g/kg, the temperature of 90oC, and the leaching time at 3 hours for each leaching stage. In addition, the best neodymium extracted achieved  76,97%, using the alkali fusion, fused in NaOH at 700oC for 3 hours.
Lembar Aktivitas Mahasiswa Materi Integral Jumlah Riemann Berdasarkan Teori Aksi, Proses, Objek, Skema (APOS) Maya Saftari; Sariman
Jurnal Inovasi Matematika Vol 3 No 2 (2021): Inovasi Matematika (Inomatika)
Publisher : Pendidikan Matematika Universitas Muhammadiyah Bangka Belitung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (565.254 KB) | DOI: 10.35438/inomatika.v3i2.200

Abstract

This study produced a prototype of Riemann's number of teaching materials based on APOS theory. The student activity sheet (LAM) based on APOS theory was designed to help students understand the integral of the subject matter of Riemann quantities. The teaching materials design process was divided into two stages, namely preliminary study and formative evaluation. In the preliminary study stage, the researchers prepared and designed teaching materials in the form of student activity sheets for the subject of Riemann's Amount based on the APOS theory (Action, Process, Object, and Scheme). In the formative evaluation stage, researchers evaluated and revised the results of the design of teaching materials. The evaluation results in the form of comments and suggestions were used to revise the products produced, namely the first, second, and third prototypes. From these three stages, the first prototype that the researcher designed was revised based on the comments from the validator, namely expert review and several students. The second prototype was revised based on comments from several groups of students in small groups. The third prototype was the final design result used for field testing at the field test stage. The trials conducted showed that the goal of producing a product design that had a potential effect (usability) in the mathematics learning process had been achieved.