Effect of temperature and sodium sulfate dosage on direct reduction – Magnetic separation of iron sand pellets using coconut shell charcoal reductant

• Main Authors: Suharto, Oediyani, Soesaptri, Pramudia, Bagas, Nurjaman, Fajar, Suhartono, Achmad, Feerzet, Sundari, Susanti
• Format: Conference Proceeding
• Language: English
• Subjects: Additives; Charcoal; Chemical composition; Direct reduced iron; Dosage; Magnetic separation; Muffle furnaces; Pellets; Phase transitions; Recovery; Reducing agents; Sand; Sodium sulfate; Steel making; Tailings; Temperature; Temperature effects; Titanium; Titanium dioxide; Titanium oxides
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0186519

The utilization of iron sand as a steel-making resource has encountered a new challenge to utilize a by-product of TiO2. Nevertheless, there is no technology that is able to process it economically. Research is being developed towards direct reduction–magnetic separation technology to obtain high grade of titanium slag and easy to process further. In this work, the effect of temperature, and the addition of Na2SO4 on the direct reduction of iron sand, which was followed by the magnetic separation process, was investigated clearly. Before being reduced, the pellets were oxidized at a temperature of 1150°C for 60 minutes. The reduction was carried out in a muffle furnace with temperatures of 1000, 1100, and 1200°C for 120 min with various dosages of Na2SO4 as additives for 0, 3, 6, 9, and 12 wt.%. After that, a wet magnetic separation process was carried out with a 500-gauss magnet to obtain a magnetic concentrate containing metallic iron and non-magnetic tailing containing titanium dioxide. The XRF, XRD, and SEM-EDS analyses were carried out to identify the chemical composition,phase transformation, and morphology of the reduced pellets. The optimum results were obtained at a temperature of 1200°C with an additional dose of 12 wt.% Na2SO4 with metallic iron grade and recovery in concentrate were 89.119% and 94.64%, respectively, while titanium oxide grade and recovery in the tailings were 19.32% and 38.23%, respectively.