Fundamentals, page-650

Now that we know that PA’s process will be a derivative of SQM’s process, I was wondering whether SQM holds any patents which we potentially could be infringing. I checked everything, and couldn’t find any relevant patents, so all good as far as I am concerned.

However, when searching the literature, I found SQM’s patent US 6,547,836 to be an interesting read, as it may provide some insight in what the process solution, after evaporation is completed, could look like, either for AGY and/or SQM’s current process.

In summary, this patent discloses a process for obtaining lithium sulfate from natural, concentrated brines, in which two brines of different compositions are used. One brine that is saturated with carnallite (KClMgCl2.6H2O) and potassium chloride (KCl), and another brine with a composition at the saturation limit of bischofite (MgCl2.6H2O) and carnallite. Once these two brine solutions are mixed together, the lithium sulfate content exceeds its solubility in the resulting brine solution and consequently precipitates out. This process pretty much takes advantage of the different solubilities of the various salts, and highly pure lithium sulfate is crystallised in a crystalliser later in the process.

Could this concept be applied for the production of lithium carbonate? Possibly. However, I don’t think it would be straight forward, and that some kind of inventive endeavour is required, which would make any process derived from the disclosed process inventive, and therefore no infringement would occur.

Also, if a process is used which utilises the combination of different brines, that would explain why PA is in no rush to start processing the first batch of brine, which was ready a while ago.

Anyway, sorry for getting carried away a bit with this, just couldn’t get started with work this morning. End of the day it’s all speculation.