Good to hear from you again.....and again, a very insightful question.
Let me see if I can break it down and answer it as follows. ( By the way, given the level of discussion I only felt it appropriate/polite to review my answer with Bernard from HPQ and, I thought you should know, he has signed off on this response as well):
First, remember that our goal is now to obtain solar grade silicon in one step (and we believe we can do that), and separately get to 5N if that makes sense. Of note, there are already technologies that produce solar silicon at less than 5N.For example, Elkem Solar Silicon has 30ppm metal impurities or 99.997% (i.e. 4N).
Second, you have properly taken actual results and projected from there that 5N could not be produced on that basis, and you are correct. However, at this stage, obtaining 5N and Solar grade silicon are two different goals. We are confident that we will eventually obtain solar grade silicon in one step, and are well down the path to doing that, but we may need to tweak the system with an additional step to get to 5N.
Third, we have seen that increasing the yield will in turn increase purity (the logic of which I will not go into here, but it makes sense), and we were limited in testing this out in the GEN 1 configuration.
Fourth, Gen 1, Gen 2, and Gen 3 are explained as follows:
Gen 1 was a batch process that was limited when it came to testing the yield/purity hypothesis
Gen 2 is a semi continuous process which will enable us to test the yield/purity hypothesis by allowing us to produce larger samples than Gen 1; this is key. We willalso be able to do something called “slow cooling” which will provide us the opportunity to further test the hypothesis using directional solidification which is planned for GEN 3.
Gen 3 is a continuous process which will run with the highest purity.
Of interest is that, by our calculations, the yield/purity benefits are maximized at the 25TPY system and that there are no further yield/purity benefits as one scales up to 200 TPY.
Last but not least our detailed report has the Boron and Phosphorous results you requested, but I will leave that up to our client to disclose those particulars.I think it is safe to say that we are very happy with the Boron and Phosphorous results in that they met or exceeded our expectations for Gen 1.