Electronic Theses and Dissertation

Hot Briquetted Iron (HBI) adalah bentuk berkualitas tinggi dari Direct Reduction Iron (DRI) yang mengalami proses reduksi pada suhu di atas 650 °C selama penyusutan, menghasilkan densitas lebih dari 5.000 kg/m³. HBI dikembangkan untuk mengatasi masalah kerusakan fisik dan egradasi material pada pengiriman DRI. Penelitian ini bertujuan mengetahui pengaruh komposisi batu bara terhadap penurunan massa serta enganalisis bagaimana variasi komposisi batu bara dalam pemanasan memengaruhi kekuatan HBI, khususnya daya tahan abrasi, kekuatan pecah, dan ingkat porositas briket HBI. Komposisi yang digunakan terdiri dari 95% besi sponge dan 5% perekat, dipanaskan pada temperatur 900 °C dengan total 6 spesimen untuk pengujian. Setelah pembentukan briket, sampel dipanaskan lebih lanjut ke dalam dapur reduksi hingga tidak terjadi penurunan massa kembali, menandakan perekat telah hilang akibat suhu tinggi. Setelah pemanasan, briket panas dimasukkan ke cetakan berdiameter 20 mm dan ditekan dengan beban 10 ton untuk memperkuat struktur fisiknya. Variasi komposisi batu bara memengaruhi penurunan massa, di mana briket dengan komposisi 70:15:5 mengalami penurunan massa tertinggi sekitar 6%. Analisis menunjukkan bahwa peningkatan variasi komposisi batu bara berbanding terbalik dengan nilai abrasi, semakin tinggi komposisi batu bara semakin stabil nilai abrasi. Dengan nilai abrasi tertinggi pada I-Type Tumbler Test sebesar 9%, dan nilai pecah mencapai nilai maksimum 4%. Untuk Drop Test nilai abrasinya 6% dan nilai pecahnya 9%. Serta porositas HBI juga berubah signifikan, di mana pengaruh komposisi batu bara menurunkan jumlah pori-pori, akibatnya sebagian material melebur pada suhu pemanasan sehingga zat sisa terbakar dan dikeluarkan, menghasilkan struktur HBI yang lebih padat dan
kuat.

Kata kunci: HBI, Pengaruh Komposisi, Daya Abrasi, Daya Pecah, Pori - Pori

Hot Briquetted Iron (HBI) is a high-quality form of Direct Reduction Iron (DRI) that undergoes a reduction process at temperatures above 650 °C during shrinkage, resulting in a density of more than 5,000 kg/m³. HBI was developed to address the problem of physical damage and material degradation during DRI shipments. This study aims to determine the effect of coal composition on mass reduction and analyze how variations in coal composition during heating affect the strength of HBI, specifically the abrasion resistance, breaking strength, and porosity level of HBI briquettes. The composition used consists of 95% sponge iron and 5% adhesive, heated at a temperature of 900 °C with a total of 6 specimens for testing. After briquetting, the samples are further heated in a reduction furnace until no further mass reduction occurs, indicating that the adhesive has been lost due to the high temperature. After heating, the hot briquettes are placed into a 20 mm diameter mold and pressed with a load of 10 tons to strengthen their physical structure. Variations in coal composition affect mass loss, with briquettes with a 70:15:5 composition experiencing the highest mass loss of approximately 6%. Analysis shows that increasing variations in coal composition are inversely proportional to abrasion values; the higher the coal composition, the more stable the abrasion values. The highest abrasion value in the I-Type Tumbler Test was 9%, and the breakage value reached a maximum of 4%. In the Drop Test, the abrasion value was 6% and the breakage value was 9%. Furthermore, the porosity of the HBI also changed significantly, with the influence of coal composition reducing the number of pores. As a result, some of the material melted at the heating temperature, causing residual matter to burn and be expelled, resulting in a denser and stronger HBI structure. Keywords: HBI, Effect of Composition, Abrasion, Breakage, Pores