Tag Archives: CLEVR

DST to help Newmont go cyanide-free with CLEVR agreement

Dundee Sustainable Technologies has entered into a Technology Transfer Licensing Agreement with Newmont for the use of DST’s cyanide-free gold extraction technology, known as the CLEVR Process™.

DST has been in ongoing discussions and technology review with Newmont regarding its CLEVR gold extraction process to evaluate and quantify its applicability on projects selected by Newmont.

Following a successful test work program in the March quarter of this year, Newmont expressed its interest in the execution of such an agreement allowing Newmont to conduct laboratory CLEVR leaching tests in its technical facilities in Englewood, Colorado.

The method used by DST uses no cyanide, produces no toxic liquid or gaseous effluent, and the solid residues are inert, stable and non-acid generating, according to the company.

David Lemieux, President and CEO, said: “We are very pleased to announce this agreement with Newmont which is the culmination of much work and dialogue between our companies. Our collaboration with a global gold producer is the result of years of continuous efforts in developing an innovative and technically sound process for the industry.”

He added: “Today’s announcement is further validation of DST’s CLEVR Process as one of the leading cyanide-free alternatives for the gold industry, and it represents an important milestone in the early-stage adoption and understanding of our technology by a world leading gold company.”

As part of the agreement, DST and Newmont, agreed to:

  • A two-year, non-exclusive licence for the utilisation of CLEVR at the laboratory scale in its Colorado technical facilities with an option to renew, for an additional two-year period under the same terms;
  • Technology implementation support by DST, including all technology laboratory protocols in addition to technical training sessions to initiate and support the technology transfer and practical operations;
  • Ongoing technology support and for DST to review the laboratory test plans, execution, and results conducted by Newmont; and
  • Any process scaling-up requirements, resulting from positive applications of CLEVR, will be conducted jointly with Newmont at DST’s technical facilities in Canada and/or on-site using DST’s technology and engineering group expertise.

The objective of the agreement is to facilitate the adoption, understanding and application of CLEVR on various gold projects being, or to be, developed by Newmont. The agreement was executed on November 25, 2020.

DST’s CLEVR Process ups gold extraction yields in metallurgical test work

Dundee Sustainable Technologies (DST) has hit a new milestone, with results from metallurgical testing on mineralised samples from a top tier gold producer achieving extraction yields of up to 95.6% with the help of its cyanide alternative CLEVR ProcessTM.

DST received a circa-10 kg sample of material from an operating gold mine in South America, with the company mandated by the producer to conduct a metallurgical test program at its facilities in Thetford Mines, Canada. The objective was to define and quantify the gold extraction amenability of the CLEVR Process on the provided material.

In May 2020, DST completed the metallurgical test program and says the direct application of the CLEVR Process on the producer’s sample achieved gold extraction yields of up to 95.6%. Given the low sulphide concentration of the sample, no oxidation was necessary before proceeding to the CLEVR Process leaching step, it noted.

The method used by DST uses no cyanide, produces no toxic liquid or gaseous effluent, and the solid residues are inert, stable and non-acid generating, according to the company.

“The direct CLEVR Process leaching, without any pre-treatment, was successful and demonstrated higher gold extraction yields (>90%) when compared with cyanidation (67.6%) tests conducted on the same material,” the company said. “DST’s standard CLEVR Process conditions were utilised, which allowed for superior gold yields in a fraction of the time (one-hour leaching time).”

In addition, the solid tailings residues produced by the CLEVR Process met the US Environmental Protection Agency’s Toxicity Characterisation Leaching Procedure and may be considered as non-hazardous waste products, DST explained.

“DST is very excited with the results obtained using the CLEVR Process and the collaboration with the producer,” the company said. “The corporation will continue its development efforts with the producer to further develop this promising opportunity and the technical and economic parameters of DST’s Technology.”

In March 2020, DST tested two distinct lots of circa-50 kg and circa-30 kg samples of representative material from a gold miner’s operating mine in the Asia-Pacific region. The laboratory metallurgical test program showed the direct application of the CLEVR Process on oxidised samples achieved gold extraction yields of 93.5% and 94.2%, respectively, for the distinct lots tested.

Dundee Sustainable Technologies makes CLEVR, GlassLock process progress with China

Dundee Sustainable Technologies says it has received a mandate from a Chinese customer to continue testing of the cyanide alternative CLEVR Process™.

The company has received a 30-kg sample of mineralised material from the customer and a payment for this work, DST said, explaining that the goal of the work is to demonstrate its proprietary CLEVR Process can extract gold at a rate of 95% or better.

Brian Howlett, President and CEO, said: “Management of DST is very excited to be developing our CLEVR Process technology into China at this time. China controls a key portion of the gold and base metals processing capacity in the world and will be a key market going forward for our technologies.”

DST, back in December, said it had completed analysis of the samples from this customer and had been able to increase recovery of the gold from the customer’s concentrate from 71% using cyanide to over 90% at a lab scale using its technology.

CLEVR uses no cyanide, produces no toxic liquid or gaseous effluent, and the solid residues are inert, stable and non-acid generating, according to DST.

DST Management has also submitted a 5-kg sample of glass from its GlassLock Process™ to Chinese authorities for regulatory testing with the goal of classifying the glass as non-hazardous waste product suitable for disposal in the Chinese market.

GlassLock is a patented process for the sequestration and stabilisation of the arsenic often associated with copper, gold, silver or polymetallic deposits.