%T Pengaruh Stirring Speed dan Solid Liquid Ratio pada Ekstraksi Timah dari Residu Dimethyl Oxide Black (Dob) dengan Metode Hydrochloric Acid Leaching %D 2026 %I Fakultas Teknik Universitas Sultan Ageng Tirtayasa %A FARRAS ARDIANSYAH %X Dimethyl oxide black (DOB) is a residue from the tin industry process that still contains approximately 60.2% Sn and has not yet been optimally utilized. This by product has the potential to be developed as a secondary tin resource to support resource efficiency and reduce industrial waste. This study aims to investigate the effect of stirring speed and solid liquid ratio on the percentage of Sn extraction during the leaching process using hydrochloric acid. DOB samples were leached using 4 M HCl solution at a temperature of 80°C for 120 minutes. The stirring speed variations applied were 300 RPM, 400 RPM, and 500 RPM, while the solid liquid ratio variations were 0.05 g/ml, 0.10 g/ml, and 0.15 g/ml. The Sn content in the solid DOB by product was analyzed using X-ray Fluorescence (XRF) and X-ray Diffraction (XRD), while the leachate was analyzed using XRF and Raman Spectroscopy. The results indicate that variations in stirring speed and solid liquid ratio do not linearly affect the percentage of Sn extraction. At a solid liquid ratio of 0.05 g/ml, changes in stirring speed have a relatively minor effect on Sn extraction due to minimal external diffusion resistance. Meanwhile, at medium and high solid liquid ratios, the percentage of Sn extraction is influenced by complex interactions between shear forces, particle suspension, and film diffusion resistance. The highest Sn extraction percentage was obtained at a solid liquid ratio of 0.15 g/ml, indicating that increasing the solid content can enhance leaching effectiveness up to a certain limit. These findings suggest the presence of an optimum stirring condition in the extraction process of Sn from DOB by products. %L eprintuntirta59572 %K Dimethyl Oxide Black, Hydrochloric acid leaching, Ekstraksi timah, Stirring speed, Solid liquid ratio