Preparation of Lead, Lead Alloy(S) And Other Salts from Exhausted Rechargeable Lead Batteries

Abstract

Metals of lead and some lead alloys, lead oxide, nickel and cobalt were recovered from exhausted battery by combined hydrometallurgy and pyro metallurgical method. The spent batteries were dismantled and leached in hot 2M and 5M nitric acid. The unleached fraction was heated with sodium carbonate to produce lead oxide. Salts in the leached solution were analyzed by Inductively Coupled Plasma ICP. Lead was precipitated as hydroxide on cold with ammonia. Nickel and cobalt metals in solution were extracted by solvent extraction using LEWATIT MP 600 ion exchange resin. Metals loaded by the organic phase were stripped by HCl. Metals hydroxides were reduced with ascorbic acid or hydrazine hydrate to ultrafine free metals, Lead alloys were prepared by encapsulating the alloying metal oxide or organic salts in the host lead metal and heated at 800 °C. The end products were investigated with Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray fluorescence (XRF), Inductively Coupled Plasma (ICP), and Scanning Electron Microscope (SEM). Results revealed that the spent grids contain 94.2 % lead, aluminium 0.12% nickel 0.05 % and cobalt 0.053 %. The particle size of the reduced metals was found in range of 15-60 um, LEWATIT MP 600 ion exchange resin is specific adsorbent for nickel and cobalt. Distribution constant Kd value of the stripping step decreased in the order Ni and Co. Lead-Al-Mg alloy was prepared by heat treatment of terminal taps at 500 °C. The obtained lead alloys were investigated with EDX and SEM. The extent of recovery of lead metal and lead calcium aluminum alloy amount to 94.3% and 96.4% with high purity. Lead -calcium alloy was homogeneous and contain calcium particles with 5 ums.