Electronic Theses and Dissertation

Prarancangan pabrik Smelter Grade Alumina dari Bauksit menggunakan
Proses Bayer dengan kapasitas produksi 800.000 ton/tahun dan hari kerja 330 hari
per tahun bertujuan untuk memenuhi kebutuhan alumina dalam negeri sebagai
bahan baku industri aluminium, mendukung program hilirisasi mineral nasional,
meningkatkan nilai tambah sumber daya bauksit Indonesia, mengurangi
ketergantungan impor alumina, membuka lapangan kerja, serta meningkatkan
devisa negara. Peningkatan kebutuhan alumina di Indonesia dipengaruhi oleh
berkembangnya industri peleburan aluminium primer, meningkatnya konsumsi
aluminium pada sektor konstruksi, transportasi, kelistrikan, dan manufaktur, serta
bertambahnya kapasitas industri pengolahan aluminium. Kapasitas pabrik sebesar
800.000 ton/tahun dipilih untuk membantu memenuhi kebutuhan bahan baku
alumina dalam negeri sekaligus memanfaatkan potensi cadangan bauksit yang
melimpah di Indonesia. Proses produksi menggunakan Proses Bayer, yaitu melalui
tahapan persiapan bahan baku, digestion, klarifikasi, presipitasi, dan kalsinasi. Pada
tahap digestion, bauksit direaksikan dengan larutan NaOH sehingga aluminium
larut sebagai natrium aluminat, sedangkan pengotor berupa oksida besi, silika,
titanium oksida, dan mineral lainnya dipisahkan sebagai limbah padat (red mud).
Selanjutnya larutan natrium aluminat diendapkan menjadi aluminium hidroksida
pada tahap presipitasi dan dikalsinasi untuk menghasilkan aluminium oksida
(Smelter Grade Alumina). Pabrik menghasilkan produk utama berupa aluminium
oksida dengan kemurnian 99,95% sebanyak 800.000 ton/tahun, serta menghasilkan
limbah padat berupa red mud sebesar 356.911,328 kg/jam. Bentuk badan usaha
yang dipilih adalah Perseroan Terbatas (PT) dengan struktur organisasi garis dan
staf. Jumlah tenaga kerja yang dibutuhkan untuk mengoperasikan pabrik ini
diperkirakan sebanyak 203 orang. Lokasi pabrik direncanakan didirikan di
Kabupaten Sanggau, Provinsi Kalimantan Barat, Indonesia yang dipilih karena
ketersediaan bahan baku bauksit yang melimpah, infrastruktur yang memadai, serta
akses transportasi yang strategis. Hasil analisis ekonomi yang diperoleh adalah
sebagai berikut:
1. Fixed Capital Investment (FCI) = Rp 1.285.441.091.452
2. Working Capital Investment (WCI) = Rp 226.842.545.550
3. Total Capital Investment (TCI) = Rp 1.512.283.637.003
4. Total Biaya Produksi = Rp 4.267.294.477.918/tahun
5. Hasil Penjualan = Rp 5.069.126.283.140/tahun
6. Laba Bersih = Rp 634.020.356.887/tahun
7. Pay Out Time (POT) = 4,04 tahun
8. Internal Rate of Return (IRR) = 28,70%
9. Break-even Point (BEP) = 39,55%
Berdasarkan studi kelayakan teknis dan ekonomis yang telah dilakukan, dapat
disimpulkan bahwa prarancangan pabrik Smelter Grade Alumina dari Bauksit
menggunakan Proses Bayer dengan kapasitas produksi 800.000 ton/tahun layak
untuk dilanjutkan ke tahap perancangan dan pembangunan pabrik. Selain itu, pabrik
ini diharapkan dapat memenuhi kebutuhan alumina dalam negeri sebagai bahan
baku industri aluminium, mendukung program hilirisasi mineral, meningkatkan
nilai tambah sumber daya bauksit Indonesia, serta mengurangi ketergantungan
terhadap impor alumina.
Kata kunci: Bauksit; Natrium hidroksida; Prarancangan pabrik; Red mud; Smelter
Grade Alumina; Proses Bayer

The preliminary design of a Smelter Grade Alumina (SGA) plant from bauxite using the Bayer Process is designed with a production capacity of 800,000 tons/year and an operating period of 330 days per year. The plant is intended to meet the domestic demand for alumina as the primary raw material for the aluminum industry, support the national mineral downstream policy, increase the added value of Indonesia's bauxite resources, reduce dependence on imported alumina, create employment opportunities, and contribute to national foreign exchange earnings. The increasing demand for alumina in Indonesia is driven by the growth of the primary aluminum smelting industry, rising aluminum consumption in the construction, transportation, electrical, and manufacturing sectors, as well as the expansion of the national aluminum processing industry. The selected production capacity of 800,000 tons/year is expected to contribute significantly to the domestic alumina supply while optimizing the utilization of Indonesia's abundant bauxite reserves. The production process employs the Bayer Process, which consists of raw material preparation, digestion, clarification, precipitation, and calcination. During the digestion stage, bauxite reacts with sodium hydroxide solution to dissolve alumina as sodium aluminate, while impurities such as iron oxide, silica, titanium oxide, and other minerals are separated as red mud. The sodium aluminate solution is then precipitated to form aluminum hydroxide, which is subsequently calcined to produce Smelter Grade Alumina. The plant produces 800,000 tons/year of aluminum oxide with a purity of 99.95% and generates 356,911.328 kg/h of red mud as a solid by-product. The company is established as a Limited Liability Company (Perseroan Terbatas/PT) with a line-and-staff organizational structure. The plant requires approximately 203 employees for its operation. The proposed plant is located in Sanggau Regency, West Kalimantan Province, Indonesia, due to the abundant availability of bauxite resources, adequate infrastructure, and strategic transportation access. The economic evaluation results are as follows: 1. Fixed Capital Investment (FCI) = IDR 1,285,441,091,452 2. Working Capital Investment (WCI) = IDR 226,842,545,550 3. Total Capital Investment (TCI) = IDR 1,512,283,637,003 4. Total Production Cost = IDR 4,267,294,477,918/year 5. Annual Sales Revenue = IDR 5,069,126,283,140/year 6. Net Profit = IDR 634,020,356,887/year 7. Pay Out Time (POT) = 4.04 years 8. Internal Rate of Return (IRR) = 28.70% 9. Break-even Point (BEP) = 39.55% Based on the technical and economic feasibility analyses, the preliminary design of the Smelter Grade Alumina plant from bauxite using the Bayer Process with a production capacity of 800,000 tons/year is considered technically and economically feasible for further detailed engineering design and construction. Furthermore, the proposed plant is expected to satisfy domestic alumina demand as a raw material for the aluminum industry, support the national mineral downstream program, enhance the added value of Indonesia's bauxite resources, and reduce the country's dependence on imported alumina. Keywords: Bayer Process; Bauxite; Plant Design; Red Mud; Smelter Grade Alumina; Sodium Hydroxide