Uragold is pleased to inform its shareholders that INRS - ETE (Institut National de la Recherche Scientifique, Eau Terre Environnement) Laboratory in Quebec City has advised Uragold that the first batch of samples produced by the PUREVAP™ Quartz Vaporization Reactor (QVR) following restart (May 25, 2016 Press Release) have been analyzed.
ANALYSIS CONFIRMS PRODUCTION OF HIGH PURITY SILICON METAL IN ALL TESTS
Multiple surface readings were completed using a Scanning Electron Microscope (SEM) associated with Energy Dispersive X-ray Spectroscopy (EDX) on samples T6, T7 and T9. The analyses confirm production of High Purity Silicon Metal (Si) by the PUREVAP™ QVR during all of the tests but the final purity level in ppb (parts per billion) is yet to be determined.
EXTREMELY LOW IMPURITY LEVELS EXCEED LAB DETECTION CAPABILITIES
Of significant interest is the fact that 22 different readings of 100% Si were observed. This can be attributed to the fact the impurity levels of the samples are so low that they were below the impurity detection level of the method utilized by INRS - ETE (1,000 ppm). As such, the method used detected purity levels greater than 99.9% Si and were rounded up to 100%. This first pass analytical process confirms the ability of the PUREVAP™ process to create high purity silicon metal exceeding 99.9% and the samples will now been sent to a specialized laboratory in the United States to determine the precise purity levels of the Silicon Metal.
"We are encouraged by these results as they confirm our expectations of our PUREVAP™ process," said Pierre Carabin, Director of Engineering of PyroGenesis. "We are looking forward to receiving the additional tests results from the specialized laboratory in the US. In the meantime, we continue to pursue our testing program."
Bernard Tourillon, Chairman and CEO of Uragold stated, "These test results represent a significant milestone as one of the key goals of our project has been reached - the establishment of a high purity (99.9+%) baseline for the material produced by the reactor. Reaching our goal of transforming Uragold Quartz into Solar Grade Purity Silicon seems even more attainable."
RESULTS ENTER PROJECT INTO NEXT PHASE
At the outset, theoretical modeling of the process indicated that transforming Uragold Martinville Raw Quartz into High Purity Silicon Metal was feasible. Today's results now validate this. Therefore, the program is now moving beyond the metallurgical testing phase into an R&D program strictly focused on improving the PUREVAP™ QVR beneficiation capability for the express purpose of determining maximum purity and advancing to the pilot plant stage.
TESTING PROTOCOL MOVING FORWARD
The original test protocols called for any material that exceeded the lower limit of detection of the SEM-EDX to be further tested using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) analysis. The Lab has advised the INRS that it lacked a High Purity Silicon Quality Assurance Standards for LA-ICP-MS analysis in order to validate results. Furthermore, because of contamination risk associated with the Inductively Coupled Plasma Mass Spectrometry testing, it was decided the material should be sent to a specialised laboratory in the US for neutron activation analysis (NAA) testing.
The SEM-EDX analysis were completed at the INRS - ETE laboratory in Quebec City.
The scanning electron micrographs (SEM) USED are Carl Zeiss EVO® 50 smart SEM equipped with a range of imaging detectors, including: an Everhart-Thornley Secondary Electron Detector, for topographic image.
Backscattered electron (BSE) images allow the viewing of images in chemical contrast, depending of the mean atomic number of the specimen. The systems use a 4 Quadrant backscattered electron detector (QBSD).
The elemental analysis of the particles present on the surface is enabled by an energy dispersive X-ray spectrometry (EDS) Microanalysis System (model: Oxford Instruments, INCAx-sight EDS Detectors). This EDS is a Lithium drifted Silicon detector Si (Li). EDS can detect element from Beryllium (z=4) to Uranium (z=92). This detector must be operated at liquid nitrogen temperatures.
- EDS Resolution: 133 eV.
- Detection limits: 1,000 ppm
Settings used for the analysis: Accelerating voltage usually used is 20 kV, Working distance: WD: 8.5 mm for EDS analysis, for image in SE.
- The samples were mounted on conventional 12.7 mm diameter aluminum stubs using double sided adhesive carbon discs. The all is clamped in a multi-stub holder.
- The samples were coated with a thin layer (20-30 nm) of conductive medium, such as gold, to increase conductivity and thus to minimise sample charge up.
Pierre Carabin, Eng., M. Eng., has reviewed and approved the technical contents of this press release.