Can we cool matters down? Below is a recent blog from one of our colleagues suggesting possibilities for calcining spodumene that might have radical implications for process temperatures.
“Could microwave energy change the way we process lithium? I have spent much of my working life looking at processes where the reactor can change the economics rather than simply improve them incrementally. Spodumene may be an interesting new example. The conventional route to lithium from spodumene normally involves heating the mineral to around 1,000°C or more before lithium can readily be extracted. Recent research into mechanically activated spodumene combined with microwave treatment suggests something rather different may be possible: processing at temperatures of only a few hundred degrees. That immediately caught my attention. At Torftech we are currently commissioning our first industrial TORWAVE® installation, combining microwave energy with the highly active moving particle bed created by a TORBED® reactor. It raises an interesting question. Could a reaction demonstrated in a laboratory microwave be translated into a single-stage, continuous industrial process? For me, the critical issue is likely to be kinetics. Can sufficient conversion occur within the residence time available in a continuously operating reactor? We don’t yet know the answer. But if the answer is yes, the opportunity becomes much more interesting than simply replacing fossil-fuel heat with electricity. It could mean redesigning the process itself and potentially eliminating a very high-temperature processing step. Our current commissioning work should teach us considerably more about the behaviour of microwave energy in a continuously moving bed of particles. Sometimes the most interesting question in process engineering isn’t “How can we heat this more efficiently?” It’s “Do we need to process it this way at all?”
In the case of spodumene, there is a potential alternative to an industrial rotary kiln for calcining.