Ann: Five Nines Graphite Purity Exceeded, page-33

If you actually read their announcement, you would see that they heated it to a temperature of 2850°C, yes this is costly but with such a high-grade ore body the cost of mining is drastically decreased. One tenth the cost of other projects as stated by SGA in their most recent presentation.

Now let's see what it takes to create synthetic graphite, synthetic graphite is produced by heating petroleum coke to 800-1000°C for 1-2 months to remove impurities this creates needle coke. Needle coke then needs to be heated to 3000°C for 1-3 weeks to undergo graphitisation.

So, SGA's graphite is heated to 2850°C once whereas synthetic is heated to 800-1000°C and then to 3000°C and both for long periods of time.