Molten Salts for Precious Metal Recovery

Case ID:
UA21-030
Invention:

This invention is a method used primarily for mining that extracts metals using electrodeposition from a mixture of refined ore and molten salt in order to reduce the melting point. Much like the process of extracting aluminum from Bauxite, gold is extracted from ore using electrodeposition as a replacement for the widely used sodium cyanide mixture.

Background:
Mining for precious metals like gold, silver, and copper fuel economies across the world. These metals are very commonplace--all of the major technology used on a daily basis requires these precious metals in some capacity. However, the state of mining technology relies heavily on cyanide in the United States and mercury and cyanide throughout the world. The health problems that stem from using poisonous mixtures are prevalent throughout the world in the environment and the surrounding populations.

This technology is a replacement for both heap leaching and vat leaching for mercury and cyanide. Using molten salts and electrodeposition allows the mining industry to transition from the poisonous processes of the past, for a more efficient, environmentally friendly process for the future. Furthermore, this process in some cases increases the amount of metal extracted from the ore. While cyanide typically recovers about 90% of precious metals after several rounds of leaching, molten salt treatment as described here recovers between 90 and 98%.
 

A similar process is used in extracting aluminum from Bauxite and has been extremely effective in that field. This technological step forward is to lower the required mixture temperature thus decreasing energy costs and making the idea more plausible for companies to adopt.
 

Not only is this technology environmentally and morally responsible, but economically efficient. Mining is essential for the lives of people across the globe. Equally essential are those who work in refineries and those who live around these mining practices. This technology can be the future of the industry and a more responsible and efficient step forward.
 

Applications:

  • Mining
  • Precious metal extraction


Advantages:

  • Environmentally conscious
  • More versatile than existing processes
  • More efficient than mercury and most cyanide processes
  • Do not require multiple leaching processes to extract the desired amount of metal
  • Lower temperature than other molten salt mixtures
Patent Information:
Contact For More Information:
Brett Mortenson
Licensing Manager, College of Engineering
The University of Arizona
BrettM@tla.arizona.edu
Lead Inventor(s):
Dominic Gervasio
Keywords: