[1]. Navarro R., Guzman J., Saucedo I., Revilla J. and Guibal E., “Vanadium recovery from oil fly ash by leaching, precipitation and solvent extraction processes,” Waste Manag., Vol. 27, pp. 425 – 438, 2007.##
[2]. Tsygankova M. V., Bukin V. I., Lysakova E. I., Smirnova A. G. and Reznik A. M., “The recovery of vanadium from ash obtained during the combustion of fuel oil at thermal power stations,” Russ. J. Non Ferrous Met., Vol. 52, pp. 19 – 23, 2011. ##
[3]. Moskalyk R. R. and Alfantazi A. M., “Processing of vanadium: a review,” Miner. Eng., Vol. 16, Issue 9 793–805, 2003. ##
[4]. Jadhav U. U. and Hocheng H., “A review of recovery of metals from industrial waste,” J. Achiev. Mater. Manuf. Eng., Vol. 54, pp. 159–167, 2012. ##
[5]. Mohanty U.S., Rintala L., Halli P., Taskinen P. and Lundström M., “Hydrometallurgical Approach for Leaching of Metals from Copper Rich Side Stream Originating from Base Metal Production,” Metals, Vol. 8, pp. 40-51, 2018. ##
[6]. Huang Z., Chun F. and Ma Y., “Ultrasonic recovery of copper and iron through the simultaneous utilization of Printed Circuit Boards (PCB) spent acid etching solution and PCB waste sludge,” J. Hazard. Mater, Vol. 185, pp. 155-161, 2011. ##
[7]. Zhang K., Li B., Wu Y., Wang W., Li R., Zhang Y. and Zuo T., “Recycling of indium from waste LCD, A promising non-crushing leaching with the aid of ultrasonic wave,” Waste Manag., Vol. 64, pp. 236-243, 2017. ##
[8]. Peronico V. C. D. and Raposo J. L., “Ultrasound-assisted extraction for the determination of Cu, Mn, Ca, and Mg in alternative oilseed crops using flame atomic absorption spectrometry,” Food Chem., Vol. 196, pp. 1287-1292, 2016. ##
[9]. Xiao J., Yuan J., Tian Z., Yang K., Yao Z., Yu B. and Zhang L., “Comparison of ultrasound-assisted and traditional caustic leaching of spent cathode carbon (SCC) from aluminum electrolysis,” Ultrason. Sonochem, Vol. 40, pp. 21–29, 2018. ##
[10]. Montgomery D. C., “Design and analysis of experiments,” 6th ed. John Wiley and Sons, New York, 2005. ##
[11]. Jiang F., Chen Y., Ju S., Zhu Q., Zhang L., Peng J., Wang X. and Miller J. D., “Ultrasound-assisted leaching of cobalt and lithium from spent lithium-ion batteries,” Ultrason. Sonochem., Vol. 48, pp. 88–95, 2018. ##
[12]. Haoyu L., Shiwei L., Jinhui P., Chandrasekar S., Libo Zh. and Shaohua Y., “Ultrasound augmented leaching of nickel sulfate in sulfuric acid and hydrogen peroxide media,” Ultrason. Sonochem., Vol. 40, pp. 1021–1030, 2018. ##
[13]. Vyas S. and Ting Y. P., “A Review of the application of ultrasound in bioleaching and insights from sonication in (Bio) chemical processes,” Resources, 7, Issue 1, 2018. ##
[14]. Rastegar S. O., Mousavi S. M., Shojaosadati S. A. and Sarraf Mamoory R., “Bioleaching of V, Ni, and Cu from residual produced in oil fired furnaces using Acidithiobacillus ferrooxidans,” Hydrometallurgy, Vol. 157, pp. 50-59, 2015. ##
[15]. Breuer P. L. and Jeffrey M. I., “Thiosulfate leaching kinetics of gold in the presence of copper and ammonia,” Miner. Eng., Vol. 13, Issue 10-11, pp. 1071-1081, 2000. ##
)