The melting atomization for powder preparation and oxidizing acid leaching of nickel-based waste superalloys containing rhenium with addition of hydrogen peroxide in sulfuric acid system were adopted for leaching of rhenium, molybdenum, tungsten, tantalum and other rare metals, nickel and cobalt were leached from waste superalloys, and tungsten, tantalum and other rare metals enriched in the leaching residue. The effects of sulfuric acid concentration, volume of hydrogen peroxide, temperature, particle size, ratio of liquid to solid and leaching time on the leaching rates of metals were examined. The optimized leaching conditions were obtained as the alloy powder 20 g, particle size 71~100 mm, temperature 75℃, ratio of liquid to solid 8 mL/g, sulfuric acid concentration 3.5 mol/L, volume of 30%(w) hydrogen peroxide 65 mL, which was dropwise added, and reaction for 6 h in sulfuric acid system. Under the above conditions, the leaching rates of nickel, cobalt and rhenium were all over 99%, those of tungsten and tantalum less than 1%, and that of molybdenum is 28%. So, Re was completely leached into solution, and rare metals were enriched in residue.
WU Jian-hui SU Tao LIU Gang ZHANG Wen-hong WEI Tao LUO Mei-mei
. Oxidizing Acid Leaching of Nickel-based Waste Superalloys Containing Rhenium[J]. The Chinese Journal of Process Engineering, 2015
, 15(3)
: 406
-411
.
DOI: 10.12034/j.issn.1009-606X.215144