Siahaan, S. D. Y., Wahyusi, K. N. ., Kurniati, E., & Nurcholis, F. . (2025). Optimization of Potassium Silicate Fertilizer Production from Fly Ash: Effect of KOH Concentration and Extraction Time. CHEMICA: Jurnal Teknik Kimia, 12(1), 18–24. https://doi.org/10.26555/chemica.v12i1.337