Electronic Theses and Dissertation

Permintaan baja nasional yang meningkat menuntut pengembangan bahan baku berkualitas seperti Hot Briquetted Iron (HBI). Namun, HBI lokal masih menghadapi kendala berupa kekuatan rendah, mudah pecah, dan rentan korosi. Penelitian ini bertujuan untuk melihat pengaruh temperatur terhadap penurunan massa dan konstanta reduksi, melihat pengaruh komposisi batubara terhadap kandungan Fe yang terbentuk, kekuatan pada HBI dan pori-pori pada HBI. Briket disusun dari campuran bijih besi, batubara muda, dan getah karet dengan empat variasi komposisi (80:15:5;75:20:5;70:25:5;60:35:5) dan direduksi pada temperatur 800°C, 900°C, dan 1000°C kemudian briket dipanas kan kembali pada temperatur 900°C hingga mengahsilkan HBI. Hasil menunjukkan bahwa peningkatan temperatur dan kadar batubara mempercepat reduksi, namun menurunkan kadar Fe dan meningkatkan porositas. Komposisi 80:15:5 memberikan performa terbaik dengan kandungan Fe 18,7 wt%, porositas 0,41%, serta nilai kekuatan tertinggi (AI 5%, BI 2%). Sementara itu, komposisi 60:35:5 menunjukkan penurunan massa terbesar (46,75%) namun dengan kandungan Fe dan kekuatan lebih rendah. Energi aktivasi juga meningkat seiring naiknya kandungan batubara.

The increasing national demand for steel necessitates the development of high-quality raw materials such as Hot Briquetted Iron (HBI). However, domestically produced HBI still faces challenges, including low mechanical strength, high friability, and susceptibility to corrosion. This study aims to investigate the effect of temperature on mass loss and reduction rate constant, as well as the effect of coal composition on Fe content, mechanical strength, and porosity of HBI. The briquettes were composed of a mixture of iron ore, sub-bituminous coal, and rubber latex with four composition variations (80:15:5; 75:20:5; 70:25:5; 60:35:5) and reduced at temperatures of 800°C, 900°C, and 1000°C. The briquettes were then hot-compacted at 900°C to produce HBI. The results showed that increasing temperature and coal content accelerated the reduction process but decreased Fe content and increased porosity. The 80:15:5 composition exhibited the best performance, with an Fe content of 18.7 wt%, porosity of 0.41%, and the highest mechanical strength (AI 5%, BI 2%). In contrast, the 60:35:5 composition yielded the highest mass loss (46.75%) but lower Fe content and mechanical strength. Activation energy also increased with higher coal content.