Pemanfaatan Alumina Waste dari Tailing Bauksit Menjadi Zeolit Adsorben

Sy Indra Septiansyah; Maya Santi

doi:10.55981/eksplorium.2018.4982

Pemanfaatan Alumina Waste dari Tailing Bauksit Menjadi Zeolit Adsorben

Sy Indra Septiansyah, Maya Santi

DOI: http://dx.doi.org/10.55981/eksplorium.2018.4982

Abstract

ABSTRAK

Alumina waste dari tailing bauksit merupakan produk samping yang berasal dari hasil benefisiasi bijih bauksit. Proses benefisiasi dilakukan dengan cara memisahkan partikel-partikel yang ada seperti lumpur atau clay, akar-akar, butiran bijih bauksit berkisar 2 mm yang dibuang atau menjadi waste product atau disebut sebagai limbah tailing. Tingginya kadar alumina dan silika dalam tailing bauksit menjadi salah satu alasan mengapa tailingini dapat dimanfaatkan sebagai bahan dasar dalam pembuatan produk baru yaitu zeolit sintetis. Zeolit sintetis dipilih karena zeolit merupakan produk impor, harganya mahal dan memiliki sifat yang seragam serta >150 jenis zeolit sintetis dapat dibuat secara komersial dan bahkan di industri zeolit dapat dimanfaatkan secara luas sebagai adsorben, penukar ion, membrane, katalis, dan lain-lain.Hasil analisis kimia tailing bauksit menunjukkan komposisi: alumina (Al₂O₃) sekitar 49,41%, silika (SiO₂) sekitar 12,58%, hematit (Fe₂O₃) sekitar 10,6% dan beberapa oksida anorganik lainnya dalam jumlah yang kecil. Proses konversi tailing bauksit menjadi zeolit adsorben dilakukan dengan metode fusi kaustik untuk mendapatkan ekstrak fusi (mother liquor) kemudian dilanjutkan dengan penambahan prekursor natrium silikat dengan formula sintesis Si/Al(1:1). Kristalisasi produk dilakukan dengan menggunakan metode hidrotermal pada suhu rendah dengan variable waktu inkubasi yang ditentukan. Reaksi sodium aluminat dan sodium silikat telah mentransformasi fasa amorf gel menjadi fasa kristalin zeolit yang berbentuk serbuk putih halus.

ABSTRACT

Alumina waste from bauxite tailings is the by products derived from bauxite ore beneficiation. The beneficiation process is done by separating the particles that exist such as mud or clay, roots, grain, bauxite ore ranges from 2 mm are discarded or be referred to as a waste product or tailings. High concentration of alumina and silica in bauxite tailings considered as one of the reasons why these tailings can be used as base material in the making new products, namely synthetic zeolites. Zeolites synthetic is selected because zeolites are imported, expensive and have uniform properties and >150 types of synthetic zeolites can be made commercially and even in industrial zeolite can be used widely as an adsorbent, ion exchange, membranes, catalysts, etc. The chemical analysis of bauxite tailings showed the composition of alumina (Al₂O₃) is approximately 49.41% silica (SiO₂) is about 12.58%, hematite (Fe₂O₃) is approximately 10.6% and some other inorganic oxides are small amounts. The conversion process bauxite tailings into zeolite is carried out by caustic fusion method to extract the fusion (alumina precursor) followed by the addition of sodium silicate precursor with synthesis formula 1.2Na₂O.0.5SiO₂.0.5Al₂O₃.10H₂O and crystallization products is carried out by the hydrothermal method at low temperatures with variable incubation period specified. The results showed that the zeolite synthesis of bauxite tailings using caustic fusion and followed by crystallization at low temperature and under atmospheric pressure has succeeded in transforming the product into an amorphous phase to the crystalline phase product zeolite adsorbent.

Keywords

tailing bauksit; fusi kaustik; hidrotermal; adsorben; zeolit sintetis

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