Tag Archives: reagents

BASF and Moleaer join up to tackle primary copper sulphide leaching issues

Base metals, Mineral processing, Mining services, Sustainable mining, , , , , , , ,

BASF and Moleaer™ Inc have announced an exclusive partnership to combine expertise in mineral processing, hydrometallurgy, gas transfer and nanobubble technology to develop what they say are innovative processes for mining.

The initial aim is to target the copper leaching process and improve extraction rates of copper ores containing high levels of chalcopyrite, which have historically been difficult to leach.

The companies explained: “Copper is extracted from primary sulphide ores through a flotation process and low-grade ores are traditionally discarded because they are too costly to process. Currently, an alternative hydrometallurgical heap leach process is employed for low-grade oxide and secondary sulphide ores. It is, however, very difficult to leach primary sulfide ores, such as chalcopyrite, which leads to low recovery efficiencies.”

Based on test work conducted by BASF, Moleaer’s nanobubble technology improves the extraction process of valuable metals such as copper.

When combined with BASF’s LixTRA™ reagent, the mineral recovery rates and efficiencies are compounded, especially in sulphide-based ores, such as chalcopyrite, they claim.

Caren Hoffman, who leads the global mining solutions business at BASF, stated: “Technological improvements and collaborations like the one we announced today are essential if the industry is to maximise the recovery of copper at existing mines. By combining BASF’s LixTRA reagent, allowing greater ore-lixiviant contact, together with Moleaer’s nanobubble technology to facilitate a higher oxidative environment, we offer technology to the industry to significantly increase copper recoveries.”

Nick Dyner, CEO of Moleaer, added: “We look forward to working with BASF, a global leader in mineral extraction chemistry, to improve the recovery of copper and help support the green economy. This important collaboration comes at a time when the ability of mining copper is only getting more costly and challenging. Moleaer’s nanobubble technology will allow the mining industry to improve the efficiency and efficacy in existing mines and narrow the gap between supply and demand of copper.”

Antofagasta readies primary sulphide leaching technology options

Base metals, Environmental, Metallurgy, Mineral processing, Mineral project development, Sustainable mining, , , , , , , , , , , , , ,

The ability to leach primary copper sulphides has, on many occasions, proved a hurdle too much, with conceptual work in the laboratory or pilot scale falling down on sub-economic or volatile recovery rates when working out in the field.

This problem tends to result in one of two things: new capital-intensive concentrators are brought into process these sulphides, or brownfield oxide operations are drafted up that prolong existing leaching operations for a few more years when – hopefully – copper prices are higher.

Antofagasta has come up with an alternative option that leverages chloride-based reagents and 20-years of knowledge leaching secondary sulphides.

Called Cuprochlor®-T, the proprietary process has undergone five years of intense development leading to the point that the company is now open to talking about its potential.

It leverages off the first iteration of leaching technology Antofagasta devised for secondary sulphides – Cuprochlor.

Cuprochlor, which is now working at the Michilla mine in Chile (which Antofagasta sold in 2016), effectively binds together the particles of mineral – particularly fine in the case of Michilla – into a porous but manageable material that can then be heap leached. The agglomeration is achieved by mixing the mineral and leach solution with chloride salts and sulphuric acid, which react to form a plaster-like paste.

Over the years, the process has been refined, going on to consistently deliver recovery rates of around 90%.

Sitting on an expansive base of primary sulphide resources – mainly chalcopyrite – and the success of Cuprochlor, Antofagasta, around five years ago, began a series of tests, adjusting variables such as temperature, reagent concentrations and particle size to see if the chloride leaching process could be adapted for the treatment of primary sulphides.

Temperature proved to be one of the keys, with tests showing that by elevating the temperature of the heap to around 30°C, Cuprochlor-T was able to stimulate the required chemical reaction for recovering copper from primary sulphides such as chalcopyrite.

Another key differentiator between the two chloride leaching technologies is the “reagent recipe” and particle size distribution (PSD), Alan Muchnik, VP Strategy & Innovation for Antofagasta, told IM.

“Providing a constant temperature throughout the process is very important, but the real innovation is the approach we have used,” he said. “It involves a combination of factors, including, among others, the recipe for reagent concentrations and the required PSD.”

While not wanting to reveal the ‘secret sauce’, Muchnik said the PSD consideration goes beyond the usual P80 industry reference point.

It is this balance that has landed the company with recoveries of over 70% after approximately 200 days of leaching on the heap in test work.

Muchnik expanded on this: “The Cuprochlor-T process, in simple terms, involves leaching in a chloride environment – where there are no passivation layer bonds. This allows for the copper, iron and chloride ions to react, which, at a controlled temperature, results in the economic production of copper.”

This is through three stages:

  • First up is an agglomeration stage where the necessary reagents are added and are left to rest at a constant aeration and temperature;
  • Second, the ore is irrigated intermittently with continued aeration, also maintained at a constant temperature; and
  • Finally, after 200 days, the ore completes the leaching cycle and allows the company to obtain recoveries of 70% copper or more.

What started with laboratory testing and progressed to pilot testing and a “semi-industrial” test on several different heaps at Centinela has recently concluded with an industrial test of over 40,000 t of primary sulphide material averaging 0.4% Cu – containing more than 90% chalcopyrite – that, using the same process outlined by Muchnik, showed consistent recoveries of over 70%, he said.

Alan Muchnik, VP Strategy & Innovation for Antofagasta

Asked if the company is eyeing even higher recoveries that can compete with the levels Cuprochlor is achieving on secondary sulphides, Muchnik said it was all about an economic tradeoff.

“It may be possible to hit such a percentage [as Cuprochlor], but that is not the aim or expectation with the kinetics we are currently seeing in Cuprochlor-T,” he said. “There is always a tradeoff between the length of irrigation time, the PSD and the recoveries, all of which are related to capital costs, operating costs and the payback associated with the process.”

The Antofagasta planning and operations teams have now got their hands on the Cuprochlor-T ‘licence’ and will be busy outlining potential deployments for consideration in the company’s annual planning cycles.

There are some obvious places to start.

The Zaldívar open-pit, heap-leach copper mine, 175 km southeast of Antofagasta, is currently in the process of transitioning to chloride leaching operations with Cuprochlor.

The project, which includes an upgrade of the SX plant and the construction of new reagent facilities and additional washing ponds for controlling chlorine levels, was completed in January 2022 and is now being commissioned. It is set to boost copper recoveries by approximately 10 percentage points, increasing production at Zaldívar by around 10,000–15,000 t/y over the remaining life of mine.

“In addition to transitioning to chloride leaching with Cuprochlor for secondary sulphides, we are currently progressing studies for the primary sulphide orebody that currently lies below the Zaldívar reserves to prove if Cuprochlor-T leaching can work,” Muchnik said. “Within our resource base, there are approximately 460 Mt of primary sulphide resources declared here.”

Both Centinela and Antucoya have primary sulphide resources and existing heap leach and SX-EW facilities that would fit the Cuprochlor-T blueprint too.

Muchnik said: “One of the technology attractions of Cuprochlor-T is the ability to use otherwise idle leach pad and SX-EW capacity. That it is the scale limitation at our current operations, but the technology can be gradually deployed within a plant that is already adapted for chloride leaching, phasing this in during the life of mine to fit requirements.

“It provides an ongoing adoption process option rather than an immediate infrastructure project that sees an operation shift from oxide leaching to a different kind of heap leaching in one go.”

The advent of Cuprochlor-T does not mean the company will completely drop potential concentration projects, Muchnik clarified, highlighting the second concentrator project currently subject to a feasibility study at Centinela.

In addition to the capital and operating cost benefits that would come with Cuprochlor-T over the concentration route, there is likely to be a sustainability benefit.

“It’s only an indicative reference as each case is different, but you would expect the energy consumption associated with Cuprochlor-T leaching and SX-EW treatment to be less than half of the normal route of copper concentration and SX-EW,” Muchnik said.

In this respect, it is a favourable consideration for Antofagasta’s long-term carbon-neutral goals.

While each potential Cuprochlor-T implementation will have to go through corresponding project studies, Muchnik was confident in predicting that new copper from Cuprochlor-T would be produced this decade.

With five years of substantial testing under its belt, not many metallurgists would bet against him.

Alpha HPA signs reagent and offtake deal with Orica

Base metals, Energy minerals, Mineral processing, Mining services, , , , , ,

The Board of Alpha HPA Limited has executed binding, definitive agreements with Orica Australia in respect of Alpha HPA’s First Project in Gladstone, Queensland.

The agreement relates to the supply of process reagents and the offtake of process by-product to/from Alpha HPA’s First Project and Orica’s Yarwun manufacturing facility within the Gladstone State Development Area in north Queensland.

The nature of the HPA First Project process is such that the use of reagents and the manufacture of by-product is highly complementary to the existing processes in operation at the Orica Yarwun facility, Alpha HPA says. The agreements secure the commitment from both Orica and Alpha to leverage the process synergies to unlock the value from both companies’ projects, it added.

The agreement comprises a Project Implementation Agreement, which describes the capital investment obligations of the parties and the scope for project commissioning and reagent and by-product validation trials. This includes the construction of the full-scale HPA First Project by Alpha HPA and, for Orica, the construction of the piping, tankage and process controls required to deliver reagents to, and receive by-product from the HPA First project.

The agreement confirms a 10-year initial term with an optional extension of 10 years by mutual agreement.

Alpha HPA’s First Project represents the commercialisation of the production of circa-10,000 t/y equivalent of high-purity alumina and related products using the company’s proprietary licensed solvent extraction and HPA refining technology. The technology provides for the extraction and purification of aluminium from an industrial feedstock to produce 4N (>99.99% purity) alumina for the intended use within the lithium-ion battery and LED lighting industry.

Nouveau Monde files US patent for thermochemical purification anode tech

Energy minerals, Metallurgy, Mineral processing, Power supply for mines, , , , , , , , , , , ,

Nouveau Monde Graphite has submitted a patent application for its proprietary thermochemical purification technology to the US Patent and Trademark Office that could see it gain intellectual property over a “greener” and more sustainable alternative process to that currently used in the traditional anode material production.

Leveraging Québec’s abundant, clean and affordable hydropower, the company’s technology avoids using hydrofluoric acid in favour of high temperatures and the addition of chlor-based reagent, it says.

Tests in labs and at third-party facilities have already demonstrated the technology’s performance and the products’ high purity, reaching 99.95% and over, according to the company.

Its Phase 1 purification facilities are in the final stages of commissioning, prior to starting production, process optimisation and material qualification with potential customers. At the same time, Nouveau Monde is carrying out its definitive feasibility study for the Phase 2 plant in Bécancour, Quebec, Canada.

The company’s 200,000 sq.m industrial site, adjacent to the Phase 1 location, is intended to consolidate manufacturing facilities for the production of 42,000 t/y of lithium-ion battery anode material and 3,000 t/y of purified flakes for specialty applications. The plant will process material from the Matawinie mine.

In addition to energy applications, Nouveau Monde’s thermochemical process has shown to be effective at purifying larger particle sizes that are expected to allow the company to supply high-purity, carbon-neutral graphite flakes for bipolar plates used in fuel cells, foils for heat dissipation in electronics, expandable graphite for fire retardant applications and other specialty products, it said.

Arne H Frandsen, Chairman of Nouveau Monde, said: “Research and development is a critical component of our business model. The filing of this important patent application is a tangible manifestation of our commitment to sustainable development and the success Nouveau Monde has already achieved from its Center of Excellence in Québec.”

Eric Desaulniers, Founder, President and CEO of Nouveau Monde, added: “I believe there is much appetite in the marketplace for alternatives to China’s dominant chemical-heavy processes. We have developed a technology that takes full advantage of Québec’s green hydroelectric asset and operates in a closed loop with our chemical supplier to minimise the environmental footprint of our purified products. This patent application reiterates our engagement towards R&D, innovation, and environmental stewardship to drive greater sustainability into the battery value chain.”

Newlox heralds the potential of OAR gold leaching technology following test work

Environmental, Metallurgy, Mineral processing, Mining services, Precious metals, Sustainable mining, Water management, , , , , , , , , , , , , , ,

Newlox Gold Ventures Corp’s affiliate has reported what it says are “excellent results” from Stage 1 testing of the new Organic Aqua Regia (OAR) gold leaching technology on high-grade gold ore samples.

Newlox Research and Development Corp’s final analysis of the results from Stage 1 testing indicated not only is a gold recovery of 94.68% achieved at ambient temperature, but also a 100% recovery is achieved at 80°C.

The company is investigating the use of OAR technology as a non-toxic and water-free alternative to cyanidation to produce both gold and other precious metals. This will benefit Newlox Gold Ventures Corp’s ambition to recover residual precious metals and contaminants from historical tailings.

Newlox R&D is developing OAR in conjunction with the University of British Columbia in Canada and Chiba University in Japan to leach gold with this reagent, which is both non-toxic and widely used in other industries, according to the company. The main advantages include that it is non-toxic, is recyclable, extracts gold faster than cyanide, does not use water, and does not require carbon or electrowinning.

The company undertook Stage 1 testing on a high-grade gold ore grading an average of 48.87 g/t. The ore was ground in a BICO mill to reach a point where 80% of the material was below a grain size of 0.12 mm (P80 -0.12 mm) before leaching with OAR. Newlox’s research team used the Yates model in 16 experiments to investigate several combinations of reagent dosage and leaching time, it said.

Newlox R&D Corp undertook leaching tests in Vancouver, with the gold dissolution in the OAR calculated based on the gold grade in residues obtained after filtration. A third-party metallurgical laboratory (Global Mineral Resources) in Burnaby, British Columbia, was used to verify the results using aqua regia digestion and Atomic Absorption Spectroscopy (AAS).

The company explained: “The R&D team used the Yates testing protocol to modify various factors during testing and evaluate their effects and relevant interactions. The Yates protocol identified the most significant factors in overall gold recovery. Most encouragingly was the feature that all samples returning over 90% recovery during Stage 1 testing had reagent dosage commonalities, indicating a clear route forward for Stage 2 testing.”

Parallel testing was undertaken at the University of Chiba in Japan on the same ores tested by Newlox R&D in Vancouver. The Japan-based team experimented with alternative reagent additives and different leaching temperatures and found significant effects based on those factors.

Leaching tests undertaken in Japan at 80°C achieved 100% gold recovery in four hours, followed by precipitation of the dissolved gold by adjusting the solution’s pH. The pH control enabled pure gold recovery while concurrently suppressing the precipitation of other elements in the precipitate.

“This promising result indicates that gold may be recovered from the solution without the need for electrowinning,” the company said.

Stage 2 testing is now underway to both reproduce the results seen in Stage 1 testing and further investigate the effect of reagent dosage, time, and temperature on leaching mechanics. Additionally, the R&D team is focused on testing both the recyclability of the OAR reagent, and methods for recovering gold from the solution.

Ryan Jackson, President & CEO of Newlox, said: “We are most encouraged to report that the first round of testing achieved up to 100% gold recovery, using the cutting-edge OAR leaching technology. This initial round of testing forms part of the Newlox R&D 12-month OAR development program.

“We are gratified to realise such early positive results. OAR leaching promises to become a paradigm-shifting technology applicable not only to the $180 billion formal global gold mining industry but also as a method to bring the $27 billion informal gold mining industry into the 21st century.”

ColdBlock and Nucomat partner to automate mineral sampling prep process

Automation, Base metals, Environmental, Metallurgy, Mineral exploration, Mining services, Precious metals, , , , , , , , , , , , , , , , , , , , , ,

Two technology companies that take laboratory efficiency and workplace safety to a new level have pooled their expertise to help automate one of the more labour intensive and risky elements involved in the mineral sampling process.

The combination of the ColdBlock Digestion 3rd Generation Product Line and Nucomat’s Compact Sample Preparation Unit will enable an automated process of “raw sample in, analysis-ready sample out at unprecedented speed and level of operator safety” for labs dealing with mineral samples, according to Nick Kuryluk, CEO of ColdBlock Technologies.

Ahead of a CEMI-hosted webinar to discuss the combination, IM put some questions to Kuryluk and Michael Van de Steene, Software Team Lead at Nucomat.

IM: Since unveiling the ColdBlock Digestion solution back in 2015 at the annual PDAC Convention, what has happened to the technology in terms of speeding up the sampling process for mining companies? I think back then, you were claiming the technology delivered fast digestion rates of between 10 and 15 minutes. Have you managed to speed this up even more?

NK: Since 2015 when we unveiled the technology at PDAC, we have focused on developing a solid evidence generation package that validated the performance of the technology in both the academic setting and the real-world setting through mining organisations and commercial laboratories.

The performance parameters that were validated include 1) high return on investment (ROI), 2) elevated workplace safety, and 3) high analytical accuracy and precision.

  • 1) The Amira Global P1196 project included SGS, Freeport McMoRan, New Gold, Centerra Gold and Newcrest. This project demonstrated that ColdBlock delivers similar analytical measurements to fire assay for gold determination and similar analytical measurements to hotblock for base metal determination (ie copper and iron determination). However, it was further validated that the ColdBlock process can be performed in minutes compared to hours and the cost savings were substantial (average of 50% cost savings vs fire assay for gold application);
  • 2) In regard to workplace safety, we eliminated the use of lead for gold determination (commonly used in fire assay) and, thus, eliminated potential lead contamination for workers and lead waste. For base metal applications, we reduced the use of hydrofluoric acid and perchloric acid in the digestion process, both of which are harmful reagents; and
  • 3) We have now published several papers. The body of work consistently demonstrates the high accuracy and precision in the recovery of elements in both mining and environmental samples. In 2019, the Geological Survey of Canada presented their work comparing ColdBlock to both microwave and hotblock for environmental applications (soils and sludges). It was demonstrated that ColdBlock improved precision from 12.9-1.3% with a 60% time saving.
The ColdBlock Digestion mechanism

The speed of our digestion system remains the same, however, it is unmatched when compared to conventional methods. We can digest sample materials for gold analysis in minutes compared to hours with fire assay. We can also digest sample materials for base metal analysis in minutes compared to hours with hotblock.

IM: Is Nucomat competing in the same sample preparation field as ColdBlock? Where do the two companies’ solutions overlap?

MVdS: Nucomat and ColdBlock Technologies manufacture complementary technologies that will take laboratory efficiency and workplace safety to a higher level.

NK: ColdBlock delivers solutions in optimising laboratory efficiency, productivity and safety:

  • Sample digestion system based on focused short-wave infrared radiation and a cooling zone;
  • Consumables and accessories;
  • Ancillary product solutions; and
  • Laboratory services in method development.

MVdS: Nucomat provides lab automation solutions for sample preparation, handling and testing for quality control laboratories. Our systems aim to control the sample preparation burden for 24/7 applications. These automated systems offer unique advantages compared to manual sample preparation, such as:

  • Operator safety;
  • Traceability and repeatability;
  • Gravimetric accuracy;
  • Validated results; and
  • Web-based remote control.

NK: Together, ColdBlock and Nucomat have joined forces to deliver a powerful solution offering a substantial ROI, elevated workplace safety and throughput while achieving high analytical accuracy and precision.

IM: How will this tie-up between the companies work? Will Nucomat be providing the automation solution for ColdBlock’s technology? How does this relate to the Amira Global P1196A project and delivering the ColdBlock 3rd Generation Product Line?

NK: This collaboration will deliver the integration of the ColdBlock Digestion 3rd Generation Product Line with Nucomat’s Compact Sample Preparation Unit (pictured below in a three reagent configuration). The combined technologies will provide an automated system capable of rapid acid dispensing and digestion. An optional making up to mass feature is also being considered. When combined, these features will enable a process of raw sample in, analysis-ready sample out at unprecedented speed and level of operator safety.

The details of the commercial framework are in progress. The integrated product line will first be offered through the Amira Global Project P1196A initiative. This will be delivered in Q2 (June quarter) 2021. The commercially available product will also be delivered through direct sales and a channel distribution model, which is targeted for Q3 (September quarter) 2021.

IM: What is the end goal of the collaboration?

NK: The end goal of the collaboration is to deliver a powerful solution to today’s challenges of sample preparation and to meet the current needs of the laboratory environment.

The aim is also to address a segment of small and mid-size laboratories that are looking for automated solutions but cannot justify the risk and ROI on a large full-scale automation system.

We aim to deliver:

  • High ROI, including high efficiency/productivity;
  • Elevated workplace safety; and
  • High analytical accuracy and precision.

IM: Is the agreement a reflection of the need to provide more environmentally sensitive sample digestion technologies that are automated to the mining and metals industry? Will the collaboration speed up the development of such a solution?

NK: The agreement is a reflection of both ColdBlock and Nucomat working together to respond to the current needs of the laboratory environment and to deliver a powerful and sustainable laboratory solution.

ColdBlock and Nucomat deliver solutions that are already proven in the marketplace. As such, this collaboration will speed up the development and commercialisation of the integrated solution.

With respect to gold application as an alternative to fire assay, we eliminate the need to use lead as part of the digestion process. So compared to fire assay, we eliminate lead waste and we eliminate lead contamination to workers.

IM: Where in the mining and metals space do you see the most demand or opportunities for deploying such a solution? Do you already have a trial lined up for the solution?

NK: The applications of our technologies are in the following spaces:

  • Mining and minerals applications such as precious metals (namely gold), base metals (such as copper, zinc, iron and nickel) and rare earth elements;
  • Metals and alloys;
  • Environmental; and
  • Other industry applications.

ColdBlock and Nucomat are working together with Amira Global to recruit participants for the Amira Global P1196A project that will see the delivery of ColdBlock’s third-generation product line with Nucomat’s automation solution. This includes both mining organisations and commercial laboratories.

Participating prospects currently come from Canada, USA, South America and Australia.

ColdBlock Technologies and Nucomat will be taking part in a CEMI-hosted webinar titled, ‘The Integration of ColdBlock Digestion with The NUCOMAT Automation System’ on December 2.