Sileach on notice!, page-20

HF would certainly make a lot of sense - if you want to dissolve silicate there are few things more effective. But I'm intrigued - I don't recall seeing this information anywhere. Do you have a link?


In this case I suppose there would be no need to ship it in as HF (phew!) - since industrial HF manufacture is via the reaction of fluorspar with H2SO4 anyway, they can just do it in situ. The economics of it will of course depend on how much is needed - not that much, I suspect. Certainly not enough to fully dissolve the silicate mineral - just modify it enough so the metal ions no longer bind. The cost has to be balanced off against the removal of the need for roasting... will be interesting to see once it's all finalised.

Anyway, your opinion may vary but IMO it makes for a substantial change, undoubtedly with various impacts throughout the flowsheet. Certainly enough to pass the fairly low bar of "inventive step" for patenting purposes.

We shall see, I suppose. I'm content to hold and wait.