Tag Archives: kasiya graphite

Sovereign Metals Limited (ASX:SVM; AIM:SVML; OTCQX: SVMLF) (Sovereign or the Company) is pleased to announce that traditional market downstream testwork conducted at leading independent consultancy ProGraphite GmbH (ProGraphite) in Germany has delivered very positive initial test results. Preliminary tests confirm that graphite concentrate produced from the Company’s Kasiya Rutile-Graphite Project (Kasiya or the Project) in Malawi exhibits prerequisite characteristics required for graphite sales into the refractory materials sector.

Highlights:

Managing Director and CEO, Frank Eagar commented: “These initial test results for traditional graphite applications are very promising. High resistance to oxidation and low levels of sulphur are two key attributes required to produce a premium graphite product for traditional refractory and foundry applications. Combining these attributes with the > 50% large flakes of the Kasiya resource provides Sovereign with multiple marketing options.

Our evaluation of coarse Kasiya concentrate for traditional applications will continue in the coming months, complementing the optimisation work on the fine (<180 micron) fraction for anode materials¹, where we have also had excellent initial results. We are very pleased that our testwork program continues highlighting Kasiya’s graphite’s premium quality.

Keeping in mind that graphite is a co-product for Kasiya, when combining these excellent results with one of the largest graphite resources globally, industry-low operating costs and lowest industry comparable greenhouse gas emissions, Kasiya presents significant advantages over its graphite peers as a long-term secure source of supply.”

Initial Test Results for Kasiya Graphite use in Refractory Materials

Flake graphite for refractory applications should have high oxidation resistance, low levels of impurities and low loss on ignition at moderate temperatures. Sample characterisation (see Table 1) showed high fixed carbon and low volatiles, confirming prior results regarding the purity of Kasiya flake graphite.

Source: ProGraphite

The oxidation behaviour of Kasiya coarse flake (>180 microns) was assessed by a standard method known as Thermogravimetric Analysis (TGA). TGA measures the weight loss of a sample at a controlled rate of increasing temperatures, with each increase in temperature held for specified time intervals (to measure weight loss at constant temperature).

TGA performed by an independent laboratory on a sample of >180-micron (µm) concentrate demonstrated no mass loss below 400°C, including the one-hour hold at 400°C (see Figure 1). Minimal weight loss occurred in the ramp-up to 650°C, with only a 6.37% mass loss for the four-hour hold at 650°C, which equates to a very-low Oxidation Rate (OR) of 1.6% per hour.

Figure 1: TGA Analysis of >180 micron Kasiya Concentrate (furnace temperature profile: purple;
absolute weight loss: red; weight loss per minute: blue)

(Source: ProGraphite) 

Oxidation resistance of graphite is a critical attribute for its use in refractory applications, where the refractory bricks are exposed to high furnace temperatures. Kasiya coarse flake also has very low levels of sulphur impurities (<0.02%), which is also advantageous for refractory applications.

Additional evaluation of Kasiya coarse flake for traditional and expandable applications is underway with results expected in the coming months.

This will complement the optimisation program for anode materials, generating the information required for offtake agreements for Kasiya graphite concentrate. 

Graphite and Titanium Alloy Export Restrictions

On 16 November 2024, Japan-based Nikkei Asia correspondents reported that China plans to tighten export controls on key “dual-use” technologies and items, including graphite and titanium alloys, in December 2024. China’s Commerce Ministry had detailed specifications of technologies and items used in both civilian and military applications that would fall under the export controls with graphite on the list. Nikkei Asia was the first news company to announce China’s antimony export restrictions in August 2024.

On 20 October 2023, Reuters reported, effective 1 December 2023, that China would require export permits for some graphite products, including natural graphite and natural graphite products critical to EV production. China is the world’s top graphite producer and exporter. According to Benchmark Mineral Intelligence, currently 75% of the world’s flake graphite and 96% of spherical graphite (used in battery anodes) come from China.

The reported restrictions further highlight the globally and geopolitically strategic nature of the Company’s Kasiya Project, which aims to become the world’s largest producer of high-grade titanium feedstock in the form of rutile and natural flake graphite.

Industrial uses of Graphite

Traditional demand for natural graphite is primarily tied to the steel industry where it is used as a component in bricks that line both blast and electric arc furnaces (“refractories”) and as a liner for ladles and crucibles. In the automotive industry, it is used in brake linings, gaskets and clutch materials. Graphite also has many other industrial uses in lubricants, carbon brushes for electric motors, fire retardants, and insulation and reinforcement products.

Figure 2: Uses of Graphite (Source: European Advanced Carbon and Graphite Association) 

Kasiya Graphite Flake Size Distribution Provides Optionality

The size of the flakes typically determines a graphite product’s use. Typically, large flake graphite is used in refractory applications, while smaller flake sizes are used in battery applications. Very small graphite flakes tend to have limited usefulness, mainly for lubricants.

The flake size distribution of Kasiya’s current graphite Mineral Reserve indicates that Kasiya’s graphite could be used for several applications. This provides the Company with optionality over offtake discussions and future supply chains to maximise revenues generated by Kasiya’s graphite co-product.

*Source: Fastmarkets; Syrah Resources Limited company disclosures: see ASX Announcement “Syrah Finalises Balama Graphite Feasibility Study and Declares Maiden Ore Reserve” here: https://announcements.asx.com.au/asxpdf/20150529/pdf/42yw7f27bc6j4d.pdf

Syrah Resources is the world’s largest listed graphite producer outside China.

Graphite in Refractory Materials

Graphite additives are used to produce refractory materials for high-temperature environments, such as the linings for furnaces, kilns, incinerators and nuclear reactors. Graphite’s key properties for use in refractory applications are its resistance to oxidation, chemical inertness, and good thermal conductivity.

Specifically, graphite is used to increase the effectiveness of the final refractory product by:

¹ Refer to Sovereign’s ASX Announcement “Downstream Testwork Demonstrates High Quality Graphite” dated 15 May 2024