en Research Paper Research Paper Ionic liquids as green solvents with high thermal stability, recyclability, low flash point, and low vapor<br> pressure, have been considered as a viable alternative in hydrometallurgical processes. In this study the leaching<br> kinetics of chalcopyrite concentrate was investigated using 1-Butyl-3-methylimidazolium hydrogen sulfate<br> (BmimHSO4) as an acidic ionic liquid. The Effect of operational parameters, including temperature, BmimHSO4<br> concentration, H2O2 concentration, stirring speed, solid-to-liquid ratio, and particle size on the rate of copper<br> dissolution of CuFeS2 were examined systematically. The highest Cu efficiency (ca. 97%) was achieved using 40%<br> (w/v) BmimHSO4, 30 %v/v H2O2, and 10 g.L-1 solid to liquid ratio for particle sizes less than 37 &mu;m at 300 rpm and<br> 45&deg;C after 180 min leaching time. Kinetics study using Shrinking Core Model (SCM) revealed that CuFeS2 leaching<br> process using BmimHSO4 follows chemical reaction-controlled process. Under these circumstances, the calculated<br> activation energy was 46.66 KJ/mol. Moreover, the orders of reaction with respect to BmimHSO4 and H2O2<br> concentration, solid to liquid ratio and particle size were estimated to be 0.539, 0.933, &minus;0.676 and &minus;1.101<br> respectively. The obtained Arrhenius constant was found to be 0.26  106. The calculation of apparent activation<br> energy using &ldquo;time given to a fraction method&rdquo; revealed that the leaching mechanism remains the same over the<br> course of time. Cu extraction, Chalcopyrite, Leaching, BmimHSO4, Ionic liquid, Kinetic 1 14 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-4501-1&slc_lang=en&sid=1 yaser moazzami yaser.moazzami@ut.ac.ir 1800319475328460016455 1800319475328460016455 No School of Mining engineering, College of Engineering, University of Tehran, Tehran Mahdi Gharabaghi mahdigharabaghi@yahoo.com 1800319475328460016456 1800319475328460016456 Yes School of Mining engineering, College of Engineering, University of Tehran, Tehran Ziadin Shafaei Tonkaboni zshafaie@ut.ac.ir 1800319475328460016457 1800319475328460016457 No School of Mining engineering, College of Engineering, University of Tehran, Tehran