Sounds like a useful recipe, if the components are widespread. However, I notice that the press release does not disclose more - probably because of the patent application.

• it seems likely that it's still a silicate, but what silicates have an (eutectic) melting point of 300-400C?
• it seems sure that they dropped limestone, but what did they add to replace it?
• if they get a patent and license it on fair terms, it might see widespread adoption
• if they get a patent and won't license it on fair terms, bah