Talga eyes graphene potential

By James Sean Dickson
Published: Wednesday, 26 November 2014

Graphene has the potential to cause a high-tech revolution in a number of industries, but the material’s commercial breakthrough has been hindered by the difficulty of producing pristine graphene on a bulk scale. Talga resources claims to have broken this impasse, following metallurgical developments at its Vittangi project. James Sean Dickson, Reporter, visited the company’s site in Sweden to assess its progress.

Talga Resources is seeking to become an industry-leading bulk producer of crystalline carbon products by late 2016, when it aims to begin mining and processing graphite and graphene at its Vittangi project in northern Sweden.

The company showed IM during a recent visit how operations were progressing at its Nunasvaara deposit, which is located within Vittangi.

Talga told IM that it believes its low cost method of producing graphite and graphene is uniquely applicable to the ore from its Swedish projects. The company also said that its process design bypasses the need for traditional comminution circuits.

"While the technology we will utilise is relatively simple, the graphite deposit we have at Nunasvaara is unique — we have conducted a lot of research and as yet we have not found mineralisation from another deposit that works with our methodology. The key to the method is the ore itself, more than the process; our deposit has a distinctive and unusual geological history," Talga’s CEO, Mark Thompson, told IM.

1  

Nunasvaara drill core boxes awaiting transfer to the company’s core processing warehouse.


1  

IM’s visit to Talga’s Nunasvaara deposit site coincided with the diamond drilling of 10 holes at the Vittangi resource, all of which were collared close to electromagnetic anomalies, and for which the company has recently received assay data which includes 46 metres at 31.4%C.


Talga has five graphite projects in northern Sweden, all of which have different mineralisation characteristics, from amorphous (microcrystalline) graphite, through to jumbo flake.

Vittangi is the company’s most developed project, Thompson told IM, adding that Vittangi has the highest grade JORC and NI 43-101 compliant graphite resource in the world. 

The project’s indicated and inferred resource totals 7.6m tonnes at an average grade of 24.4% contained graphite (Cg), though some areas have recorded grades of over 48% Cg. Vittangi’s graphite flake distribution is predominantly made up of material less than 75µm - often defined as amorphous graphite.

A scoping study on the Vittangi project was recently released by the company, which is progressing its permitting process for a bulk mining operation and a pilot plant, scheduled to open in mid-2015.

The study suggested a relatively low capex requirement of A$29.2m ($25m*), at a 30% accuracy level, which Talga said is minimised by the simplicity of its plant requirements.

While graphene could provide significant income for the company, Nunasvaara could operate on graphite revenues alone, Talga told IM, explaining that this would reduce the risk to of entering the still embyronic graphene market.

Talga told IM that its current focus is centred on the prospectivity of its graphite and graphene projects in northern Sweden, ahead of other non-core mineral holdings in iron, copper and gold. 

Revenue from Nunasvaara has already started to come in, following the sale of samples to a German nanoprinting company and graphene research facilities, which have used material from surveyed and assayed drill cores.

1  

The high carbon content of Talga’s drill core material, which recently returned assay data in excess of 48% Cg, is visible to the naked eye.


1  

A rig operator inspects the drill mechanism during operation. 


Shift to graphene

Thompson told IM that metallurgical work on the Nunasvaara ore samples directed his attention to graphene additives, and other bulk applications for the high-tech material, rather than just scaled graphite production. 

This is a significant departure from the graphene scepticism of July 2013, when Thompson told IM: "I like traditional markets, the more basic the better." The test work on the Nunasvaara samples revealed a graphene production method that Talga claims is simpler and far less expensive than methods adopted by rival producers.

"The planned process plant will use a series of steps adopted in other mineral processing industries, but in a non-conventional way that specifically suits Nunasvaara-type graphite ore," Thompson told IM.

The comminution circuit will incorporate a series of cells that subject whole ore blocks to a wet, physio-chemical technique that liberates graphene and waste products without any primary crushing, grinding or screening.

During the comminution stage, both colloidal graphene and particulate graphite will be separated in a single step to form individual recovery streams. The graphene stream will be further filtered, sized and dispersed into specific solutions for bulk transport to meet customer requirements. 

1  

Talga’s mining and processing method would utilise solid blocks of graphite — the company’s metallurgical work details how the proposed production method does not require crushing and grinding for the liberation of the graphene and graphite products. 


The graphene produced from Talga’s metallurgical programme has been shown to be of very high quality, with few internal structural flaws, holes and tears, the company said, adding that this increases the reach of its applications.

Talga told IM that other graphene separation methods usually involve a large number of steps, which increases cost and can introduce structural flaws because of the processing disturbances.

Talga attributes its belief in its competitive cost advantage primarily to the removal of the need for preliminary crushing and grinding in its metallurgical process, which is usually ascribes significant capex and opex costs to a project.

Vittangi’s graphite also has a specific set of conductive mafic "waste" minerals, meaning that immediately saleable graphite electrodes could be produced at low cost on a lathe, with no further processing.

Jalkunen, another graphite project owned by the company, was recently announced to be amenable to the same graphene production method as Vittangi. Talga said that it believes that the deposit shares the same 2bn year old graphite formation.

*Conversions made November 2014.

Graphene uses

First prepared in the lab in in 2004, having been theorised since the 1960s, graphene could be utilised in circuitry, construction, packaging, batteries, green energy and hundreds of other industries.

Its breaking strength, which is 100 times that of steel, means the mass of steel and concrete needed for construction could fall dramatically. In packaging, because graphene’s crystal structure allows nothing to penetrate it, except water, its addition to packing material could significantly improve the shelf lives of products.

Batteries could benefit from graphene’s high conductivity and its potential for use as an anode material. It could also make a highly efficient semiconductor, owing to its unusual physical properties.

For now, many of these potential uses remain theoretical, or at the research and development stage. Production tonnages remain small, and scaled commercial production is yet to occur. IM’s 2012 Natural Graphite Report suggested that total world graphene production was only around 20 tonnes in 2012.

The report, however, contained an estimate by Korea IT, Standard Resources, that despite modest production tonnages, the total economic effect on the world from graphene in 2013 would be Korean won (K) 14.23 trillion ($13.11bn).

As research intensifies and businesses become more aware of the material’s wide implications, the economic effect is expected to grow significantly, and the Korean research predicted that in 2018, graphene’s economic effect on the world will reach K24.9 trillion ($22.93bn).