A process for the recovery of neodymium as a value added product from waste hard disk of personal computers

Abstract

The present invention relates to a process for the recovery of rare earth metal neodymium (Nd) as value added product from scrap hard disk of personal computers (PCs). This invention particularly relates to the recycling of neodymium as a valuable product from obsolete hard disk of personal computers by sulfuric acid leaching followed by selective precipitation of neodymium and leaching of the precipitate in 5-25% hydrogen fluoride solution. The novelty of the present invention is the production of a marketable value added product of pure neodymium fluoride (NdF3) by selective precipitation of neodymium from the sulfate solution of magnet of discarded hard discs. The precipitate formed from the leach liquor at a particular pH, was a double salt complex of Nd formed using sodium hydroxide (NaOH) solution. This precipitate formed was further treated with hydrogen fluoride (HF) solution. After dissolution of Nd-Na double salt in hydrogen fluoride, a white precipitate of neodymium fluoride settles down. The process not only conserves the natural resources but also meet the strict environmental regulations.