NML signs MoU for gold extraction by e-waste recycling

RNS: CSIR-National Metallurgical Laboratory ( NML) has signed a MoU for technology transfer to M/s Exigo Recycling Private Limited, New Delhi for the extraction of cobalt and gold from the lithium cobalt battery of mobile phones and gold coated surface of e-waste, respectively. The company’s CEO, Raman Sharma is very much satisfied with developed technology and is soon willing to start the process on ton scale in association of NML. Dr Indranil Chattoraj, director, CSIR-NML, was present during the transfer of MoU through audio-visual conferencing.

One of the scientists present there explained that these types of collaboration work initiated by CSIR-NML would be helpful to demonstrate the recovery of metals like cobalt and gold on large scale. This initiation will not only prove to be fruitful to the unorganised sectors, but also meet the need of the market. This will help to establish a proper collecting system. As nowadays, the quantity of these discarded equipment is increasing with disquieting rate all over the world due to rudimentary disposal, improper collection system as well as lack of cost-effective technology for processing them. Among these e-waste, mobile phones, constitutes a major fraction of e-waste. Lithium ion batteries (LIBs) dominantly used in mobile phones consist of metals, organic chemicals and plastics materials. Moreover, gold containing electronic scraps are wasted due to lack of proper processing technology. Presence of such precious and valuable metals do not allow us to dispose them. But in India, especially in case of LIBs, random chopping of scrap batteries to get metal values is done. In this course of processing, the black powder containing LiCoO2 along with many hazardous organic liquids is thrown which contaminate the soil and underground water.

However, the scraps generated during manufacturing printed circuit boards (PCBs) also contain significant amount of gold, which either wasted or smelted as exported. Therefore, development of a recycling technology to recuperate metals from such scraps has gathered great attention as this step will not only protect the environment but also improve the utilisation of secondary resources. CSIR-NML has developed a complete and novel process which consists of physical beneficiation, leaching, solvent extraction, precipitation and electro-winning processes for recycling of spent lithium ion batteries to get value added product (metal or salts) and protect the environment, based on zero waste concept.

Moreover, the extraction of precious metal gold was also successfully developed using the hydrometallurgical route of leaching and adsorption/ cementation.  The novelty for the cobalt extraction process is the development of complete recycling flow-sheet for the recovery of plastics and all metals such as Co, Cu, Mn and Fe from scrap LIBs. Feasible and environmental friendly flow-sheet is also developed for gold coated electronic scraps (some printed circuit boards manufacturing scraps were provided by the Exigo Company) to extract pure gold metal.

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