Tag Archives: Dundee Sustainable Technologies

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.

Dundee’s GlassLock Process engineers an opening at West Africa gold mine

Dundee Sustainable Technologies (DST) and its proprietary GlassLock Process™ is to help a West Africa mine stabilise legacy arsenic-bearing material at its gold operation following a new mandate agreement.

The mandate agreement, entered on June 8, consists of delivering an engineering package for a plant using DST’s GlassLock Process. It follows a preliminary metallurgical test program with the same customer from back in the March quarter.

This program saw over 40 kg of arsenic- and gold-bearing material received at DST’s technical facilities in Canada, whereby DST successfully combined gold recovery with the stabilisation of arsenic using GlassLock, it said.

A glass product containing over 15% arsenic was generated and successfully met the requirements of the United States Environmental Protection Agency’s toxicity characterisation leaching procedure (TCLP, Method 1311), DST said.

“As a result, the customer awarded the engineering mandate to DST to perform process optimisation and an engineering study at the prefeasibility (+/-25%) level,” it said. “The agreement includes engineering fees in the amount of C$101,000 ($74,436) to be paid to DST for this work as per its business plan to generate revenues for the corporation while the technology is progressing toward implementation.”

The final report is due at the beginning of September 2020, DST said.

Back in May, DST announced it had entered into a commercial agreement to provide engineering services to a gold and copper producer for a full-scale plant of its GlassLock Process as part of a C$600,000 Class 4 engineering package.

Since the construction of its pilot plant in 2016, DST has continued to demonstrate the validity of its technology, moving from pilot level to the industrial demonstration scale, where arsenical material was processed to generate vitrified arsenical glass, containing up to 20% arsenic while meeting the TCLP Method 1311.

“GlassLock is becoming an effective and cost attractive technique to segregate arsenic and is therefore opening new opportunities for arsenic-bearing precious metals deposits, concentrates or contaminated sites considered to contain too much arsenic to be exploited,” the company said.

This agreement is another major achievement in DST’s commercialisation efforts, it added.

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.

BacTech, GMR, Dundee Sustainable Technologies to revisit Snow Lake gold project

BacTech Environmental, GMR and Dundee Sustainable Technologies are joining together to develop a potential solution for the remediation of the gold residual stockpile in Snow Lake, Manitoba.

As part of this effort, BacTech has signed a letter of intent with GMR to license its proprietary bioleach technology.

Through this agreement, BacTech received a C$20,000 ($14,689) cash payment as an advance on the right to use the bioleach technology on the project. In addition, BacTech will earn 3% undivided equity interest in the net income of the project.

This proprietary bacterial oxidation technology liberates precious and base metals from difficult-to-treat sulphide ores and concentrates, according to BacTech. This is a safe and environmentally-friendly process that has the advantage of improving metal recovery at significantly lower capital and operating costs when compared with traditional treatment methods of smelting, roasting and pressure oxidation, the company said.

BacTech said: “GMR is relying on BacTech’s historical research conducted in 2011-12 that showed oxidation rates of 95% and gold recovery of 88.6% on material obtained from the arsenic stock pile.”

It added: “Due to a lack of iron in the stockpile the residual material could not be stabilised and was abandoned.”

Ross Orr, CEO of BacTech, said: “Our return to Snow Lake is predicated on Dundee Sustainable Technologies providing a solution to the unstable arsenic product we generated in our earlier work that killed the project. The stockpile has a deficiency in iron leading to an unstable ferric arsenate product after bioleaching. By passing this unstable material to be vitrified, the arsenic can be safely disposed. We look forward to re-engaging in the Snow Lake project.”

David LeClaire, the CEO of GMR, said: “BacTech’s historic work on the project and its proprietary bioleach technology, teamed with DST’s vitrification technology, is a promising solution to the remediation of a longstanding environmental concern of the community of Snow Lake without cost to the taxpayer.”

The project consists of a stockpile of arsenopyrite concentrate proven to contain residual gold and silver. BacTech drilled and assayed the stockpile, which is currently the responsibility of the Government of Manitoba, in 2011 and produced a NI 43-101 report.

Current measured mineral resource estimates were generated in 2012 by BacTech estimating the Snow Lake concentrate stockpile contains 264,596 t grading 9.76 g/t Au and 2.17 g/t Ag. In addition, indicated resource estimates include 9,300 t grading 9.2 g/t Au and 2.15 g/t Ag, and an inferred mineral resource came in at 28,000 t at 7 g/t Au and 2.4 g/t Ag.