Sarytogan Graphite Ltd (ASX:SGA) has achieved five nines purity graphite, producing 2.2 kilograms of graphite at up to 99.9992% carbon, further broadening the offering of value-added products from its namesake graphite project in Kazakhstan.
Importantly, this Sarytogan 'five nines' graphite is more than 50 times purer than battery specification and is expected to be suitable for the nuclear industry — thereby attracting super premium prices.
“Sarytogan Five Nines Graphite broadens the product offering from Sarytogan, from industrial uses to advanced battery applications and now a range of nuclear uses,” said Sarytogan managing director Sean Gregory.
“Subject to certification and qualification, this product is expected to attract super-premium prices in the nuclear industry.
“The pre-feasibility study is continuing to advance on schedule and we expect to be able to quantify the economics associated with taking our giant and exceptionally high-grade deposit into the premium battery anode market and now super-premium nuclear industry market.”
Thermal purification
The bulk flotation concentrate produced in Australia late last year was purified by the company’s American technology partner at 2,850 degrees Celsius. The carbon content was averaged at 99.9991% over the 2.2 kilograms purified.
One 570-gram sub-sample, purified with a specific set of process parameters, assayed 99.9992% carbon.
The remaining impurities were assayed for 17 elements, using one of only two machines in the USA with precision available at these low levels. These 17 elements had very low total contaminants of less than 1.2 ppm.
Nuclear uses
The addition of nuclear applications adds another layer to Sarytogan’s product strategy to place as many units of carbon into as many markets as possible.
Graphite has been an indispensable part of the nuclear fission reactor since its invention in the late 1930s. Its primary use is as the moderator surrounding the uranium fuel rods to bounce escaping neutrons back to the uranium to moderate the release of energy.
To be suitable for use as a moderator in nuclear reactors, graphite should be a fine powder at very high purity of greater than 99.999% carbon.
Impurities of elements other than carbon may capture, rather than bounce, the escaping neutrons. Boron has a particularly large neutron capture cross-section which is detrimental to the moderator’s performance. The Sarytogan Five Nines Graphite assayed at 0.032 ppm boron — well below the maximum nuclear specification of 2 ppm.
Another 26 elements can also have a lesser effect on the performance of the graphite moderator and, together, those elements give an equivalent boron content (EBC), which has a specification of up to 3 ppm.
The Sarytogan five nines product has so far been assayed for 11 of these 26 elements and all have a negligible contribution to EBC, while earlier assays of the Sarytogan flotation concentrate didn’t raise any concern for the other elements. The company says that the full suite of 26 elements will now be assayed to provide a certified EBC value.
In addition to the moderator, high-purity graphite is used in the nuclear industry for other applications including yarns, seals, lubricants, coatings, foils and reflective materials.
The global market for nuclear graphite is about 60,000 tonnes per annum and set to grow with the renewed worldwide investment in nuclear power.
Graphite used as nuclear moderators sells at prices of higher than US$25,000 per tonne — a significant premium to graphite used in lithium-ion batteries.
Lithium-ion battery testing continues
The company also confirms it is proceeding with the manufacture of Sarytogan coated spherical purified graphite (CSPG) and the testing of lithium-ion batteries made with Sarytogan CSPG. Long-cycle battery testing is continuing on batteries for which short-cycle testing was previously reported.
These results are all important inputs into the pre-feasibility study, which is on track to be completed no later than by the third quarter of this year.