HM X-Leach Proven (Non-Cyanide) Based Formulas

Non-toxic, economical and effective alternative to cyanide leaching

Iberian Minerals is in late-stage development on a patent pending, eco-friendly, non-cyanide based leach extraction of precious and rare earth metals from ore and electronic waste (eWaste). Working out of our laboratory in Coquitlam, British Columbia, the HM X-leach proven (non-cyanide) based formulas have an effective recovery rate to 99%, is reusable with no toxic chemicals.

  • Non-toxic, economical and effective alternative to cyanide leaching
  • Proven, patent pending non-cyanide based formulas and processes
  • Effective recovery rates to 99%
  • Reusable
  • No toxic chemicals
  • Full laboratory facility in Coquitlam, British Columbia

Cyanide is acutely toxic to humans, other mammals and aquatic species at relatively low dosages. Cyanide is used in the majority of gold processing operations simply because it is cheap and effective. Replacing cyanide with non-toxic leach extractions (lixiviants) stands to reduce environmental risks and open other opportunities in the many countries where gold cyanidation is banned.

Cyanide Mining 

For over 100 years, cyanide has been the leach reagent of choice in gold mining because of its high gold recoveries, robustness and relatively low costs. The cyanide solution still remains the most widely used hydrometallurgical process for the extraction of gold from ores and concentrates.  According to the International Cyanide Management Institute, approximately 1.4 million metric tons of hydrogen cyanide is produced annually worldwide, with approximately 190,000 metric tonnes used to produce cyanide reagents for gold processing, representing a global market of over US $400 million.

A series of recent environmental accidents at various gold mines around the world, however, has precipitated widespread concern over the use of cyanide as a leach reagent.  It is against the background of these environmental impacts that indigenous groups and representatives of the NGO community in particular have lobbied for the mining industry to develop alternative, less toxic, leach reagents.   Internationally, Argentina, Costa Rica, the Czech Republic, Germany, Hungary and Turkey have legislated a ban on cyanide mining. In the United States, cyanide mining is banned in a number of states including Montana and Wisconsin.

Stop cyanide gold mining

Both the use and disposal of cyanide present significant safety and environmental risks.  Cyanide and cyanide gas are both extremely toxic and great care has to be taken during ore processing to avoid exposure for workers.  Solutions containing cyanide have to be carefully managed to prevent the formation of cyanide gas.  In addition, there are significant problems with the disposal of cyanide-containing waste.

Growing environmental and health concerns about the use of cyanide have also resulted in legislation of stringent rules or prohibitions, as well as public pressure against cyanide use in gold processing worldwide. The primary challenge in devising a suitable substitute for cyanide in gold processing lies in developing an equally effective and degradable leach reagent, which is not a persistent environmental toxin. As gold cyanidation rates are relatively slow, the industry has been searching for faster gold leaching reactions capable of facilitating high metal recovery rates. Alternative lixiviants or leaching agents should also be inexpensive and recyclable, selective, non-toxic and compatible with downstream recovery processes.

Non – Cyanide Alternatives                 

Environmenat Globe - Alternative lixiviants or leaching agents

There is an increasing interest in finding new alternatives or improving previously tried processes. Numerous other chemicals have been tested to leach gold, and they include thiosulfate, thiocyanate, ammonia, bromine, chlorine, bisulfides, and thiourea. There has also been a lot of experimentation with various biological media for recovering gold from ores, but no one has come up with a more cost-effective and productive method than leaching with cyanide until now.


UBC and Iberian Minerals Enter Into Reseach Collaboration on X-leach

A $45,000 research collaboration was awarded through Mitacs, a national training and research organization, which connects companies with university researchers to apply their specialized expertise.

HM-X-leach Development & Independent Analysis 

PictureA  PictureC PictureB  Picture E

HM X-leach Comparative Matrix

The following table compares the  HM X-leach formula to some the more prominent alternatives to cyanide.


HM X-Leach





pH Sensitivity




Leach Kinetics








Hazard Classes (WGK) *








Detox Costs


Off Gas Controls




High Temperature




$ Price to Cyanide




Capital Costs




 *  1: low hazard to waters;     2: hazard to waters;     3: severe hazard to waters;


e-Waste Industry

Electronic waste is the fastest growing portion of the municipal waste stream

HM X-leach will play a significant role in the extraction of valuable metals contained in eWaste. Every 60 seconds, 38 tons of eWaste is generated, making it the fastest growing portion of the municipal waste stream. An estimated 70-80% of the eWaste that is given to recyclers in the US is exported to third world countries. 320 tons of gold and 7.500 tons of silver are now used annually to produce PC’s, cell phones and tablets, adding more than $21 billion in value to the metals eventually available through urban mining of eWaste.

  • EPA reports that in 2015, 3.41 million tons of e-Waste was generated in the USA
  • Only 24.9% (850,000 tons) of that amount was recycled
  • e-Waste is expected to rise as much as 500% over the next decade
  • 320 tons of gold and 7,500 tons of silver are now used annually to make PC’s, cell phones and tablet computers adding more than $21 billion in value to the metals eventually available through “urban mining” of e-Waste
  • One ton of circuit boards creates the same amount of precious metals as 150 tons of commercial grade ore
  • One ton of cell phones contains 1,980 ozs of silver, 10.9 ozs of gold and 4.5 ozs of palladium
  • Over 80% of e-Wast is shipped to third world countries