Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras

A Selective and Efficient Process for the Extraction of Noble Metal Ions from Complex Mixtures

Technology Category/Market

Chemical Technology: Extraction precious metal like gold, palladium and platinum and others.

Industry: Metal extraction plants, electronic waste, mining waste, wastewater treatment plant, and Electronics Industry

Applications: Jewelry, Catalyst, Electronics, Battery, others.

Market: The global precious metals recovery market was valued at USD 9.4 billion in 2021 and projected to reach USD 18.7 billion by 2030, growing at a CAGR of 7% from 2022 to 2030.

Targeted Industries

Watermarking IP design,

Electronic circuits

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Problem Statement

  • Generally, the extraction of noble metals from minerals and their subsequent processing requires highly reactive conditions and toxic chemicals.
  • There were few methods discussed related to recovery of gold and other precious metals including iron in the prior art of literatures, which were more cost effective and caused to water and soil pollution.
  • The present invention overcomes the above-mentioned deficiencies by providing environment-friendly solution.


The present invention describes a process for extraction of noble metal ions comprising hereinbelow:

  1. Reaction of styrene monomer with niacin at 90 degrees Celsius   with the presence of potassium persulfate and surfactant sodium deodecyl sulphate (SDS) in the in situ polymerization process produces niacin-incorporated polystyrene.
  2. Exposing the noble metal containing ionic mixture to the niacin-incorporated polystyrene to form a complex and separating the noble metal adsorbed polystyrene-niacin complex.
  3. A polystyrene-niacin composite selectively adsorbs noble metal ions from a solution from harsh industrial conditions with pH 1 to 3. Niacin is a biomolecule.

The noble metal includes Au, Pd, Rh, Pt, Ru, Ag, Ir and etc.

The aqueous medium contains various metals in ionic form with concentrations 10, 100 and 1000 times than the noble metal ions present in the mixture.

The polymeric adsorbent can be used with other technologies.

Key Features/Value Proposition

Technical Perspective:

  • 1.Present invention is selective, high cost effective and sustainable for noble metal extraction using a new functionalized niacin complex with polystyrene.
  • Said materials could be used in a wide range of pH conditions (1 to 7) and different concentration of Au solution which is very low to very high concentration and ideal mining conditions(depicted in Figs and Tables 1 and 2).

Industrial Perspective:

  • Said functionalized niacin complex with polystyrene is not water-soluble and could be used for industrial metal extraction such as Au, Ag, Pd, Pt, Rh, Ru, etc., from the said complex mixture.
  • Simple and Green Methodology for extraction of industrial metals from ores, using soft Chemistry approach.
Questions about this Technology?

Contact for Licensing

Research lab

Prof. Pradeep T

Department of Chemistry

Intellectual Property

  • IITM IDF Ref. 2339
  • IN Patent No. 417781 (Granted)

Technology Readiness Level

TRL- 3/4

Proof of Concept Ready & tested and validated in Laboratory stage.  

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