Ti leaching from activated ilmenite–Fe mixture at different milling energy levels

Mechanical activation processes on ilmenite concentrate were performed in three different energy levels. Iron powder as a reducing agent was added to ilmenite in the milling stage and the mechanically activated mixture was subjected to acid leaching. The leaching experiments were designed using the Taguchi method, and the optimum ranges were obtained. Furthermore, response surface methodology (RSM) was used to optimize the critical parameters in the leaching system to achieve the highest titanium (Ti) leachability. Based on the inductively coupled plasma-optical emission spectrometry (ICP-OES) results, maximum leaching recovery of Ti (80%) was obtained using activated Ti concentrates at a medium activation energy level, which is calculated to be 25.38 kJ/g, using 15vol% hydrochloric acid (HCl), a temperature of 70°C, leaching time of 3 h, and a solid-to-liquid ratio of 0.05 g·mL–1. Intensifying the milling energy from a low to high level led to a decrease in the mean crystallite size and also structure homogenization at the high energy level. According to the transmission electron microscopy (TEM) images, the mean grain size of the ilmenite/Fe nanocomposite was about 30 nm at the medium energy level sample. Finally, solvent extraction by tributyl phosphate (TBP) was performed on the leach liquor to separate dissolved Fe (the major impurity) from Ti, which led to 83% extraction recovery of Ti.

[1]  G. Durand,et al.  Solvent extraction of titanium by tributylphosphate, trioctylphosphine oxide and decanol from chloride media , 1997 .

[2]  T. S. Mackey.  Acid Leaching of Ilmenite into Synthetic Rutile , 1974 .

[3]  F. Padella,et al.  Ball milling: An experimental support to the energy transfer evaluated by the collision model , 1996 .

[4]  S. Kotrlý,et al.  Handbook of chemical equilibria in analytical chemistry , 1985 .

[5]  David J.W. Grant,et al.  Fractional factorial designs for optimizing experimental conditions for Hiestand's Indices of Tableting Performance☆ , 1998 .

[6]  T. Chernet.  Applied mineralogical studies on Australian sand ilmenite concentrate with special reference to its behaviour in the sulphate process , 1999 .

[7]  Arthur I. Vogel,et al.  Vogel's Textbook of Quantitative Chemical Analysis , 1989 .

[8]  C. Suryanarayana,et al.  Mechanical alloying and milling , 2004 .

[9]  K. C. Sole.  Recovery of titanium from the leach liquors of titaniferous magnetites by solvent extraction: Part 1. Review of the literature and aqueous thermodynamics , 1999 .

[10]  Ulrike Diebold,et al.  The surface science of titanium dioxide , 2003 .

[11]  A. Przepiera,et al.  Kinetic Model For The Reaction of Ilmenite With Sulphuric Acid , 2001 .

[12]  G. Kelsall,et al.  Reduction of tiIV species in aqueous sulfuric and hydrochloric acids i. Titanium speciation , 1996 .

[13]  S. Srikanth,et al.  Effect of mechanical activation on the kinetics of sulfuric acid leaching of beach sand ilmenite from Orissa, India , 2004 .

[14]  Archana Agrawal,et al.  An overview on the production of pigment grade titania from titania-rich slag , 2006, Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA.

[15]  Brian E. Conway,et al.  Modern Aspects of Electrochemistry , 1974 .

[16]  J. Stokes,et al.  Design of Experiments Study of Hydroxyapatite Synthesis for Orthopaedic Application Using Fractional Factorial Design , 2011, Journal of Materials Engineering and Performance.

[17]  M. Ghadiri,et al.  Paromomycin loaded solid lipid nanoparticles: Characterization of production parameters , 2011 .

[18]  B. Murty,et al.  Milling maps and amorphization during mechanical alloying , 1995 .

[19]  Xiaoqing Wang,et al.  Preparation of porous rutile titania from ilmenite by mechanical activation and subsequent sulfuric acid leaching , 2008 .

[20]  Z. Heiba,et al.  Hydrolysis of TiOCl2 leached and purified from low-grade ilmenite mineral , 2013 .

[21]  E. Narita,et al.  Manufacture of Pure Titanium(IV) Oxide by the Chloride Process. II. Selective Extraction of Titanium(IV) and Iron(III) from Hydrochloric Acid Leach Liquor of Ilmenite Ore by Tributyl Phosphate , 1983 .

[22]  F. Padella,et al.  Mechanical alloying of the Fe−Zr system. Correlation between input energy and end products , 1991 .

[23]  F. Albert Cotton,et al.  Advanced Inorganic Chemistry: A Comprehensive Text , 1972 .

[24]  Wolfgang Ziegler,et al.  Modern Aspects Of Electrochemistry , 2016 .

[25]  A. Afifi,et al.  Reductive leaching of ilmenite ore in hydrochloric acid for preparation of synthetic rutile , 2004 .