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HPQ PUREVAP QRR Produces High Purity Silicon Metal from Low Purity Quartz Feedstock

PyroGenesis Canada Inc., a clean-tech company (the "Company" or "PyroGenesis") that designs, develops, manufactures and commercializes plasma waste-to-energy systems and plasma torch products, is pleased to announce today that, further to its press release of November 2nd, 2016, the PUREVAP™ process can now produce high purity silicon metal in excess of 4N (99.99%) from a low purity quartz feedstock. Testing continues to reach the ultimate goal of producing solar grade silicon metal.

During these latest series of tests, the feedstock purity used was on average 98.14% and silicon metal was produced and collected in a laboratory furnace (Figure 1).

Figure 1 - Silicon metal produced in the laboratory furnace: http://media3.marketwire.com/docs/figure1129.jpg

Multiple measurements were taken, the results of which exceeded the detection limits of the instruments used and as such, we can say with certainty that a minimum purity level of 4N has been reached. Future testing will be done using more sensitive instruments.

Overall impurity removal was extremely efficient. Iron, which was the most abundant impurity, has been completely removed, as was Calcium. Table 1 reflects the removal efficiency of a number of different contaminants.

Table 1 - Comparison of the impurity levels in the feedstock versus the Silicon Product

Material Feedstock Mixture
(ppm)
Silicon Product*
(ppm)
Difference
(%)
Al 285 78 -73%
Ca 865 0 -100%
Fe 4508 0 -100%
Mg 37 0 -100%
Mn 50 0 -100%
Na 158 0 -100%
K 66 0 -100%
Ti 9 0 -100%
P 61 20 -67%
S 58 0 -100%
W 0 0 N/A
B 4 0 -100%
Total 6102 98 -98%
*0 means below detection limits (< 0.01%)

"These results are significant as the prevailing proposition suggests that the quartz purity level required to make high purity silicon metal is over 99.5%1" said P. Peter Pascali, President and CEO of PyroGenesis. "The PUREVAP™ has proven that to no longer be the case. We have demonstrated that the process can produce high purity silicon metal from significantly lower purity quartz as feedstock. The implications of this are enormous when considering the potential commercial applications of the process. Conceivably, we can now take a cheap and abundant low purity quartz feedstock and transform it into a high value end product."

The PUREVAP™ is a process being developed by PyroGenesis in which quartz is transformed into silicon metal in one-step; effectively eliminating significant overheads thereby creating a simple, pure and cheap alternative to that currently available. Management believes this process could have a significant impact on the solar industry. However, given recent developments, there seems to be significant commercial applications at lower purity levels as well (i.e. above 99.9%).

"We are extremely pleased with the progress to date," said Pierre Carabin, CTO of PyroGenesis. "We have now reached the detection limits of two analysis methods and confirmed the ability of the process to produce silicon metal of at least 99.99% purity. This confirms that we are truly on the right path to something unique and closer to our ultimate goal of 6N."

"Producing 4N+ material from low purity feedstock is another major milestone reached by our team on the road to transforming quartz into solar grade silicon metal," said Mr. Pascali. "Key milestones are being reached and the path towards higher purity levels is becoming ever clearer. We do not expect the future to be without its challenges, but so far, the results produced continue to be better than what we had anticipated."

Source: http://www.pyrogenesis.com/

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