Analisis Hasil Pemurnian Silika dari Slag Feronikel Metode Piro-Hidrometalurgi

Abstract

Slag feronikel merupakan produk samping peleburan nikel laterit yang mengandung silika (SiO2) dan berpotensi dimanfaatkan sebagai sumber silika sekunder. Penelitian ini bertujuan menganalisis komposisi kimia, karakteristik fasa kristalin, dan efisiensi ekstraksi silika hasil pemurnian dari slag feronikel melalui metode piro-hidrometalurgi menggunakan X-Ray Fluorescence (XRF) dan X-Ray Diffraction (XRD). Pemurnian dilakukan melalui proses alkali fusion, pelindian, dan presipitasi dengan variasi formulasi slag:Na2CO3 sebesar 80:20, 50:50, dan 30:70 (%b/b). Hasil penelitian menunjukkan bahwa kandungan SiO2 meningkat dari 40,70 %b/b menjadi 73,57 %b/b, 75,57 %b/b, dan 78,37 %b/b, disertai penurunan MgO dan Fe2O3 hingga tidak terdeteksi. Efisiensi ekstraksi silika tertinggi diperoleh pada formulasi 80:20 sebesar 61,74%. Analisis XRD menunjukkan bahwa formulasi 30:70 dan 50:50 menghasilkan silika yang didominasi fase amorf, sedangkan formulasi 80:20 menghasilkan fasa amorf-kristalin. Formulasi 50:50 merupakan kondisi optimum berdasarkan kemurnian SiO2 dan karakteristik fasa silika.

Ferronickel slag is a by-product of laterite nickel smelting that contains silica (SiO2) and has the potential to be used as a secondary source of silica. This study aims to analyze the chemical composition, crystalline phase characteristics, and efficiency of silica extraction from purified silica from ferronickel slag through pyro-hydrometallurgical methods using X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). Purification is carried out through alkaline fusion, leaching, and precipitation processes with variations in slag:Na2CO3 formulations of 80:20, 50:50, and 30:70 (%b/b). The results showed that the SiO2 content increased from 40.70 %b/b to 73.57 %b/b, 75.57 %b/b, and 78.37 %b/b, accompanied by a decrease in MgO and Fe2O3 until it was not detected. The highest silica extraction efficiency was obtained in the 80:20 formulation of 61.74%. XRD analysis showed that the 30:70 and 50:50 formulations produced silica that was predominantly amorphous, while the 80:20 formulation produced an amorphous-crystalline phase. The 50:50 formulation is the optimum condition based on the purity of SiO2 and the characteristics of the silica phase.