Vanadium removal from roasted LD converter slag: Optimization of parameters by response surface methodology (RSM)

• Published in: Separation and purification technology Vol. 116; pp. 175 - 183
• Main Authors: Mirazimi, S.M.J., Rashchi, F., Saba, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2013
• Subjects: Alkaline roasting; LD converter slag; leaching; mixing; Optimization; response surface methodology; slags; sulfuric acid; temperature; Vanadium; Alkaline roasting; Optimization; LD converter slag; Vanadium
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2013.05.032

•Alkaline roasting-acid leaching was carried out to remove the vanadium from LD converter slag.•Extraction of vanadium from slag is important from both environmental and economic point of view.•Optimization of parameters was done by response surface methodology to maximum vanadium recovery.•Box–Cox power transformation was applied to normal the data and derive the best model.
Alkaline roasting-sulfuric acid leaching process was used to remove vanadium from LD (Linz Donawitz) converter slag. Leaching parameters were investigated and optimized in order to maximize the recovery of vanadium as the vanadium content in the slag is low. The independent leaching factors investigated were liquid to solid ratio (L/S) (10–20mL/g), temperature (40–70°C), sulfuric acid concentration (1.5–3.0M), stirring rate (500–700rpm) and time (60–120min). Response surface methodology (RSM) was used to optimize the process parameters. To choose the best model for describing the leaching process, Box–Cox power transformation technique was used which in turn was used to normalize the data. The most influencing parameter was found to be L/S and the less effective was stirring rate as well. Based on the results, optimum removal condition (approx. 96%) according to process parameters was obtained with L/S ratio of (19.99), temperature of (70°C), sulfuric acid concentration of 2.05M, rpm of (558) and leaching time of (60min), respectively.