Mr. Bernard Tourillon of HPQ-Silicon reports
HPQ PUREVAP QRR SUCCESSFULLY PRODUCES 99.99+% (4N+) SILICON METAL USING 98.14% SIO2 FEED, R&D TESTING ONGOING TO REACH HIGHER PURITY LEVELS
HPQ-Silicon Resources Inc. is informing its shareholders that PyroGenesis Canada Inc. has just submitted a new stage report pertaining to high-purity silicon metal test results recently produced using the first-generation set-up of the lab-scale Purevap quartz reduction reactor (QRR), combined with the addition of a purifying agent.
Analysis confirms production of 4N-plus silicon metal (99.99 plus per cent silicon)
Multiple analyses of the material produced during test 19 were completed at the Centre de Caracterisation Microscopique des Materiaux, located at the Ecole Polytechnique de Montreal, using a scanning electron microscope associated with a wavelength-dispersive spectroscopy (WDS).
The results from test 19 confirm production of 4N-plus-purity silicon metal (99.99 plus per cent Si). At this stage, the final purity level of the material in the less-than-100-part-per-million range has not been determined. Since this test was the last prior to the upgrades of the lab-scale Purevap QRR, these positive results will be incorporated into the plans for all future testing in which samples will be routinely analyzed to much lower detection limits. Research and development (R&D) lab testing is still continuing, and the project is on schedule for completion in January, 2017.
"We have officially reached the 4N milestone, and the technical team now can focus on the improvements to follow up the achievement of the 4N-plus high-grade silicon core. The Purevap QRR results once again exceeded our expectations at this early stage of development testing. The presence of a high-grade core of material and the evidence of zonation in which impurities are forced to the outside is exactly what we were working toward, and this result has come earlier than expected. In addition, production of 99.99 plus per cent Si using 98.14 per cent silicon dioxide feed speaks volumes about the economic opportunities that the Purevap QRR represents for HPQ-Silicon and its numerous high-grade quartz deposits, in our objective of becoming vertically integrated," said Bernard Tourillon, chairman and chief executive officer of HPQ-Silicon. "Furthermore, testing and process improvements are being made on a continual basis, as our goal of making solar-grade silicon gets closer to becoming a reality."
Analytical results indicate zonation production of a high-grade silicon core
More importantly, the analytical data point to directional crystallization of a core of higher-purity silicon metal, as well as zonation of the impurities as observed in other purification processes. This apparent zonation indicates that the Purevap process has now achieved a physical segregation of residual impurities at lab-scale stage. The groundbreaking importance of this is the initial production of a higher-purity core section of the silicon material, which is where the targeted 6N silicon would be expected to accumulate in the future. This core of high-purity silicon material would then be extracted and sold as solar-grade silicon. The less-pure portions, where the impurities have migrated, would then be separated and sold as high-value silicon metal byproducts.
Further characterization of impurities to follow
The WDS analytical method provides quantitative analyses of precise spots with a detection threshold of approximately 0.01 per cent, or 100 parts per million (weight basis). The results confirm impurity levels to as low the detection limit of 0.01 per cent (less than 100 parts per million) for almost all the major impurities. This positive result means that going-forward material produced from continuing test work, which will focus on improvements to the purification process and adaptation to the pilot plant development, will now be sent for detailed analysis and characterization of the impurities, in the less-than-100-part-per-million range, to fully evaluate the effectiveness of the Purevap QRR.
"We are extremely pleased with the progress to date," said Pierre Carabin, chief technology officer of PyroGenesis. "We have now reached the detection limits of two analysis methods and confirmed the ability of the process produce silicon metal of at least 99.99-plus-per-cent purity. This confirms that we are truly on to something unique."
Test key parameters
The feedstock for experiment No. 19 was 300 grams of a mixture using a 2.5:1 weight basis of two-millimetre to four-millimetre quartz lot No. A16- 09153 from Ronceveaux and activated carbon No. 5,566 provided by Asbury Carbon. The overall purity of the quartz is evaluated at 98.14 per cent.
IMPURITY LEVELS FOR THE QUARTZ, THE CARBON AND THE RESULTING MIXTURE
Material Quartz Carbon Mixture
No. ID A16-09153 5,566 2.5:1 m/m
Units (ppm) (ppm) (ppm)
Al 265 337 285
Ca 71 2,848 865
Fe 6,295 39 4,508
Mg 0 131 37
Mn 70 2 50
Na 148 184 158
K 0 229 66
Ti 12 2 9
P 0 215 61
S 0 204 58
W 0 0 0
B 5 3 4
The quartz and the carbon were both analyzed using a combination of ICP-AES (inductively coupled plasma-atomic emission spectroscopy) and ICP-MS (inductively coupled plasma atomic-mass spectroscopy) by third party laboratories. The impurity concentrations of the mixtures are a weighted average of the ones of the reagents in respect to their mass ratio (2.5:1). It can be noted that the impurity levels in the resulting mixture are relatively high, especially in iron, which is a difficult element to vaporize.
Results
As shown in the attached table, four of the five different locations analyzed on the sample were of a purity of 4N-plus (99.99 plus per cent) with a mean purity of 99.99 per cent. The main contaminants were aluminum and phosphorus with 0.008 per cent and 0.002 per cent, respectively, in average. Interestingly, the concentrations were below the detection limits for all the other contaminants for all locations.
ELEMENTARY CONCENTRATION IN % OF THE SAMPLE AT 5 LOCATIONS
Location 1 Location 2 Location 3
Elements (%) (%) (%)
Si 99.99 100.00 99.99
Al 0.01 Less than 0.01 Less than 0.01
P Less than 0.01 Less than 0.01 0.01
W Less than 0.01 Less than 0.01 Less than 0.01
Fe Less than 0.01 Less than 0.01 Less than 0.01
Mn Less than 0.01 Less than 0.01 Less than 0.01
Ti Less than 0.01 Less than 0.01 Less than 0.01
Ca Less than 0.01 Less than 0.01 Less than 0.01
K Less than 0.01 Less than 0.01 Less than 0.01
S Less than 0.01 Less than 0.01 Less than 0.01
Mg Less than 0.01 Less than 0.01 Less than 0.01
Na Less than 0.01 Less than 0.01 Less than 0.01
C Less than 0.01 Less than 0.01 Less than 0.01
B Less than 0.01 Less than 0.01 Less than 0.01
Location 4 Location 5 Average
Elements (%) (%) (%)
Si 99.99 99.98 99.99
Al 0.01 0.02 0.008
P Less than 0.01 Less than 0.01 0.002
W Less than 0.01 Less than 0.01 0.000
Fe Less than 0.01 Less than 0.01 0.000
Mn Less than 0.01 Less than 0.01 0.000
Ti Less than 0.01 Less than 0.01 0.000
Ca Less than 0.01 Less than 0.01 0.000
K Less than 0.01 Less than 0.01 0.000
S Less than 0.01 Less than 0.01 0.000
Mg Less than 0.01 Less than 0.01 0.000
Na Less than 0.01 Less than 0.01 0.000
C Less than 0.01 Less than 0.01 0.000
B Less than 0.01 Less than 0.01 0.000
"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 per cent," said P. Peter Pascali, president and chief executive officer 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."
Further information on the test
During the phase 1 -- proof-of-concept test, the produced silicon was only collected at the surface of the graphite electrode. Now, not only is silicon produced at the surface of the electrode, but is also accumulated at the bottom of the crucible.
The R&D lab testing is still continuing, and the project is on schedule for a January, 2017, completion. By the end of the process characterization phase, PyroGenesis expects to have conducted between 40 and 50 laboratory-scale experiments. The data collected during the process characterization phase will be used for the pilot-scale design, which is also currently under way.
Testing methodology
Scanning electron microscopy, energy dispersive X-ray spectroscopy and wavelength-dispersive X-ray spectroscopy analysis were completed at the Centre de Caracterisation Microscopique des Materiaux, located at the Ecole Polytechnique de Montreal.
Pierre Carabin, Eng, MEng, has reviewed and approved the technical content of this press release.
About HPQ-Silicon
HPQ-Silicon Resources is a junior exploration company planning to become a vertically integrated and diversified high-value silicon metal (99.9 plus per cent Si) and solar-grade silicon metal (99.9999 per cent Si) producer.
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