Sarytogan Graphite Ltd (ASX:SGA) has produced the first spheroidized graphite from its Sarytogan Graphite Deposit in central Kazakhstan, confirming that graphite from the deposit is suitable for use in lithium-ion batteries for electric vehicles.
Importantly, the result allays all concerns regarding the fine nature of Sarytogan graphite with all all five elements of the flowsheet now demonstrated for the production of uncoated spherical purified graphite (USPG) and ultra-high purity fines (UHPF) for the lithium-ion and other battery markets.
The combined mass yield of the spheres produced was 54%, which compares favourably with the 35-50% yield typically achieved in China. The remaining 46% is the UHPF, which is also expected to be a high-value product for use in batteries.
"Allays all doubts"
Sarytogan managing director Sean Gregory said: “What a way to end the year! This result allays all doubts of the giant and exceptionally high-grade Sarytogan Graphite deposit’s suitability to vie for a share of the rapidly growing lithium-ion battery market for electric vehicles and other uses, subject to customer qualification.
“We have now complemented the ultra-high purity of 99.998% with these outstanding physical spheroidization results at high yields of ideally sized spheres. We now charge into 2024 on a mission to measure the battery performance of these products.”
Sarytogan Graphite spheres before and after classification.
All flowsheet elements demonstrated
Sarytogan reports that all five elements of the flowsheet have now been demonstrated for the production of uncoated spherical purified graphite (USPG) and ultra-high purity fines (UHPF) for the lithium-ion and other battery markets.
The first element of the flowsheet is the giant and exceptionally high-grade mineral resource of 229 million tonnes at 28.9% total graphitic carbon (TGC) while the second element is the flotation, where the graphite is upgraded to greater than 80% TGC, which has now been demonstrated at the bulk scale.
The third element of the flowsheet, for the thermal option, is agglomeration where the graphite is bound into coarser beads to facilitate gas flow permeability allowing the sublimated diluents to vent through the fluidised bed reactor during the subsequent thermal purification step.
A fourth element of the flowsheet is thermal purification. The company, along with its American technology partner, has achieved purity of up to 99.998% carbon. This is 25 times purer than the typical chemical specification for lithium-ion batteries of 99.95% carbon — meaning it has impurities of just 20 parts per million as opposed to 500 ppm.
Producing spheroidized graphite, as announced today, is the fifth element of the thermal flowsheet and the final piece required for the USPG and UHPF products to be tested in advanced battery applications.
Elements of thermal flowsheet option for the Sarytogan Graphite Project.
Looking ahead
Sarytogan says that next year’s test work will be market development focused. The spheres are targeted for the rapidly growing lithium-ion battery market and specifically for electric vehicles.
The performance of the spheres in coin-cell lithium-ion batteries will be measured in short-term and long-term cycling tests. The short-term tests are expected to be available in the first quarter of 2024.
The fine UPHF by-product will be tested in a host of other commercially available advanced battery systems such as alkaline, lithium primary and lead-acid batteries, and also as a conductivity enhancer in the cathode of lithium-ion batteries.
An alternative chemical purification flowsheet is also under development in Germany. This result is an important input into the PFS which is progressing towards completion no later than the third quarter of next year.