relation: https://eprints.untirta.ac.id/58225/ title: EKSTRAKSI LOGAM BESI DARI RESIDU BAUKSIT DENGAN METODE REDUKSI LANGSUNG DAN PEMISAHAN MAGNETIK MENGGUNAKAN ADITIF BORAKS (Na2B4O7•10H2O) creator: Hanif, Muhammad Chair subject: T Technology (General) subject: TN Mining engineering. Metallurgy description: Bauxite residue is a solid waste generated from the Bayer process during the conversion of bauxite ore into alumina, characterized by high alkalinity and significant potential for environmental contamination. In Indonesia, bauxite residue production reached approximately 1.95 million tons in 2024, corresponding to alumina production of 1.3 million tons. The residue is primarily composed of iron oxide compounds, predominantly hematite (Fe2O3) and goethite (FeO(OH)). This study investigates the extraction of iron from bauxite residue through a direct reduction process using palm shell charcoal as a reducing agent and limestone as a Slag-forming material. The reduction experiments were conducted under varying temperatures (1050°C, 1150°C, 1250°C, and 1350°C), basicity ratios (0.8, 0.95, 1.1, and 1.25), additive types (CaF2, Na2CO3, H3BO3, and Na2B4O7·10H2O), and borax contents (0%, 2%, 4%, and 6 wt%), with a constant reduction time of 60 minutes and a carbon-to-iron oxide ratio (C/O) of 1.17. The reduced products were subsequently separated using magnetic separation at a magnetic field intensity of 2400 Gauss. Under optimum conditions—C/O ratio of 1.17, reduction time of 60 minutes, reduction temperature of 1350°C, basicity of 1.1, and magnetic separation particle size of 74 μm—the process achieved a total iron content of 94.55%, an iron metallization degree of 96.37%, and an iron recovery of 96.27%. Phase and morphological analyses revealed that the metallic iron particles formed under optimal conditions were more homogeneous, with sizes exceeding 50 μm. The dominant phases in the iron concentrate consisted of metallic iron (Fe), magnetite (Fe3O4), and austenitic iron (γ-Fe). In contrast, the Tailings indicated that most SiO2 and other oxides were incorporated into the Slag and transformed into an amorphous phase after reduction, with residual magnetite (Fe3O4) remaining in the Slag, while unreduced iron was present primarily as fayalite (Fe2SiO4). The recovered iron metal demonstrates strong potential for applications in the automotive, construction, energy, and machinery manufacturing sectors. date: 2026-02-10 type: Thesis type: NonPeerReviewed format: text language: en identifier: https://eprints.untirta.ac.id/58225/1/Muhammad%20Chair%20Hanif_3334210086_Fulltext.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/2/Muhammad%20Chair%20Hanif_3334210086_01.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/3/Muhammad%20Chair%20Hanif_3334210086_02.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/4/Muhammad%20Chair%20Hanif_3334210086_03.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/5/Muhammad%20Chair%20Hanif_3334210086_04.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/6/Muhammad%20Chair%20Hanif_3334210086_05.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/7/Muhammad%20Chair%20Hanif_3334210086_Ref.pdf format: text language: en identifier: https://eprints.untirta.ac.id/58225/8/Muhammad%20Chair%20Hanif_3334210086_Lamp.pdf format: text language: id identifier: https://eprints.untirta.ac.id/58225/9/Muhammad%20Chair%20Hanif_3334210086_CP.pdf identifier: Hanif, Muhammad Chair (2026) EKSTRAKSI LOGAM BESI DARI RESIDU BAUKSIT DENGAN METODE REDUKSI LANGSUNG DAN PEMISAHAN MAGNETIK MENGGUNAKAN ADITIF BORAKS (Na2B4O7•10H2O). S1 thesis, Fakultas Teknik Universitas Sultan Ageng Tirtayasa.