Technical memo, Update on the SEM/EDS analysis conducted at the...

PYI~OGENC515 Document Type Technical Memo

Document Title SEM/EDS analysis conducted at the CM2

Document No. Rev. No. Issue Date(YYYY-MM-DD) Page 1M-2016-756 .21 2016-09-23 1 of 10

Quartz Refining

IPN No.: 2931

TM-2016-756, Rev. 00 GM 70022

Technical Memo

Update on the SEM/EDS analysis conducted at the (CM) ai w:

~ 3 iFa DIrECTIpN GEN_ftA4 DE LA GES T fCN DU MILIEU M , NIER

Distribution List Name Organisation Coordinates Bernard Tourillon HPQ Resources [email protected]

Patrick Levasseur HPQ Resources [email protected]

Approvals Name Signature

Prepared by: Christopher A. Dion, Eng., M.A.Sc. f/ , /

Checked by: Christine Bryce, Eng., Ph.D.

Approved by: Pierre Carabin, Eng., M.Eng. ? -° e -~. %:.

Revision List Revision No. Date By Description 00 2016-09-23 CADD Initial Release

PyroGenesis Canada Inc., 1744 William Street, Suite 200, Montréal (Québec), H3J 1R4, Canada,

Phone: +1-514-937-0002, Fax: +1-514-937-5757, Email: [email protected]

© 2016, PyroGenesis Canada Inc.

DR- I ÊOLOOIQU

2 7 AVR. 201? /160506 1

Z.

This document contains proprietary and confidential technical and business information of PyroGenesis Canada

Inc. Any copy, reproduction, distribution or use of this document, in whole or in part, which has not previously

been approved in writing by PyroGenesis Canada Inc. is strictly forbidden.

e

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A jYPYROGCNCSIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM-2016-756 ,D n -", ": c - 7 '7, 2 of 10

1.0 Introduction

HPQ Silicon (formerly Uragold Resource Bay) owns quartz properties in Quebec, from which they wish to

make an added-value product. PyroGenesis Canada Inc. (PCI) proposed a laboratory-scale proof-of-

concept study to investigate the transformation of quartz to high-purity silicon using plasma.

This report summarizes the test conducted during this initial stage and the analysis of samples collected.

2.0 Test summary D.-a-TON

Table 1 presents a summary of the tests conducted during the proof-of-concept testing phasse

Table 1—Tests conducted during the Proof of Concept testing phase

Test

(#) Date Description Result

Analysis Available

(Y/N)

1 2016-03-29 First test hot test No sample produced N

2 2016-04-07 Increased power input sample produced N

3 2016-04-08 Reduced heat losses Test Failure N

4 2016-04-15 Changed electrode tip Test Failure N

5 2016-04-20 New electrode seal Test Failure N

6 2016-05-09 New electrode design Sample produced Y

7 2016-05-10 Additional insulation Sample produced Y

8 2016-05-13 Larger carbon particle size Test Failure N

9 2016-05-13 Pre-dried carbon source Sample produced Y

10 2016-05-25 Changed base design Sample produced Y

11 2016-05-30 Changed base design No sample produced N

12 2016-06-16 Smaller quartz particle size No sample produced N

13 2016-07-05 Mixture of quartz particle size

Traces of metal

produced N

14 2016-07-13 Reproduce previous test

Traces of metal produced N

15 2016-07-22 Improve heat losses Sample produced Y

16 2016-09-02 Conventional non-vacuum arc No sample produced N

Test #15 was considered the most successful, being the first test to produce a small grey and metallic

nugget versus the black, glassy chunks collected from previous tests. It would represent a significant

breakthrough if that small nugget proved to be high-purity metallic silicon. The nugget from test #15 is

shown in Figure 1.

This document contains proprietary and confidential technical and business information of PyroGenesis Canada Inc. Any copy, reproduction, distribution or use of this document, in whole or in part, which has not previously


PYROGCNCSIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM-2016-756 3 of 10

Figure 1— Small shiny chunk produced during test #15

3.0 Analysis Procedure

The sample underwent analysis at the Centre de Caractérisation Microscopique des Matériaux (CM)2, a

material characterization laboratory affiliated with the École Polytechnique de Montréal. The (CM)2 was

selected for the quality of its equipment, the competency of its personnel, and its fast turnaround time.

The analysis of the sample had multiple purposes:

• Confirm whether the chunk was principally pure silicon or an intermediate compound

• Obtain an estimate of the purity of the sample

• Gather data offering clues to the reaction mechanism

The combined techniques of Field Emission Gun-Scanning Electron Microscope-Energy Dispersive

Spectroscopy (SEM-FEG-EDS) provided compositional data, including elemental purity analysis for

silicon. The apparatus at (CM)2 is shown in Figure 2. For this stage of the project and considering the

quantity of sample available, the attainable accuracy of ±0.1 wt% was acceptable.

SEM is a common microscopy technique that produces images of a sample by scanning it with a focused

beam of electrons. Coupled with EDS and FEG, the equipment can produce images indicating both

chemical and morphological contrast. By default, the equipment provides images in shades of grey, but

colours can be attributed to certain elements in order to more clearly demarcate contrasts between the

chemically different regions of a sample.

The sample was prepared for analysis by freezing it into a Bakelite matrix and polishing it in successively

finer diamond solutions until the surface had a mirror finish. The sample ready for analysis is shown in

Figure 3.



Figure 2 — FEG-SEM-EDS apparatus at (CM)2

Figure 3 — Sample ready for FEG-SEM-EDS analysis

Ar hYROGCNCSIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page

TM-2016-756 -) _ _ _ 4 01 10

1605061

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PYI~OGENESIS V Document

Document Type Technical Memo

Document Title SEM/EDS analysis conducted at the CM2

No. Rev. No. Issue Date(YYYY-MM-DD) Page

TM-2016-756 00 201E .:9-22 5 of 10

4.0 Sample Overview

Figure 4 shows an overview of the whole sample, coloured to differentiate chemical composition more

clearly. As indicated in the figure, the pink zone is mainly elemental silicon; and the green zone is

carbon, exhibiting veins that have been penetrated by the silicon. The densely textured exterior zone

corresponds to the surrounding Bakelite matrix.

imrn

Figure 4 — Sample overview, where pink colour indicates elemental silicon

Key observations drawn from this analysis are:

• The silicon seems to encapsulate the carbon, indicating that quartz melts and wets the surface

of the carbon.

• The carbon material is porous, allowing silicon to diffuse into the particles.

• There is an interface between carbon and silicon, coloured a dark pink, which seems to

correspond to an intermediate reaction product.




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7 PYROGCNCSIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM-2016-756 ,; 221 - ._. -. 6 of 10

5.0 Identifying the Interface Composition

The appearance of the carbon zone merited further investigation, as it exhibited a significant amount of

silicon within its structure. By zooming in on the pores, as shown in Figure 5, we see the interface as a

light grey gradient between silicon (white) and carbon (dark grey), similar to Figure 4. It is interesting to

observe evidence of the same phenomenon at two different scales.

Figure 5 — Higher magnification view of the carbon pores (chemical contrast mode)

The small size of the pores provides a thin sample for SEM analysis, which scans electrons at a relatively

broad depth of field, and therefore limits the accuracy of composition measurements by this technique.

Nevertheless, using EDS, the white material was identified as pure silicon and the interface zone as

silicon carbide (SiC), confirmed by comparison to a standard reference material. SiC is therefore strongly

hypothesized to be an intermediate reaction product.

Further analysis was conducted on a sample of the bulk-bulk interface between carbon and silicon,

external to the pores, clearly captured in Figure 6. The broader field depth in this case is expected to

provide more representative results. Figure 7 shows the analysis of the light pink zones, confirming that

the sample contains 100% silicon. Results of the analysis of the intermediate zone (darker pink) in Figure

8 are 51% Si and 49% C, which most probably corresponds to SiC. Similar results were obtained with a

commercial SiC standard.



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1T''PYI~OGENESIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM2016756 C :,—,1 ,---, 5; -'.3 7of 10

10,01.m -

Figure 6 — Interface zone (dark pink) between silicon (pink) and carbon (black) in a bulk sample

Figure 7 —Analysis results for the pink zone in Figure 6, confirming 100% silicon



I~YI~OGENESIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page

1M-2016-756 00 2016-09-23 8 of 10

1000 — IN Spectrum 16 At%

C 51.0 Si 49.0

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0 2 4 6 8 keV.

Figure 8 — Intermediate phase evaluated to contain 51% carbon and 49% silicon (atomic basis)

Figure 9 shows the element concentration profile at the interface, which supports the theory of a

chemical contrast between these three zones. As carbon concentration decreases from left to right, the

concentration of silicon increases. Interestingly, this change is not gradual as one might expect, but

varies in steps.

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A ItsPYROGENESIS

Document Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2

Document No. Rev. No. Issue Date(YYYY-MM-DD) Page

TM-2016-756 .... C,_, S 9 of 10

Figure 9 —Concentration profiles for carbon and silicon throughout the interface

Finally, using a morphological rather than a chemical contrast, Figure 10 shows crystal growth within the

carbon. As silicon dioxide (quartz) is well-known to decompose into silicon monoxide at high

temperature, this gaseous reaction intermediate is hypothesized to diffuse through the pores of the

carbon pellet to form pure silicon crystals.




PYROGENESIS

DocumAt Type Technical Memo Document Title SEM/EDS analysis conducted at the CM2 Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM-2016-756 •_.,. 23:15 5 ' . 10 of 10

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Figure 10 — Silicon crystal growth in the pores of the carbon

6.0 Conclusions and recommendations

Analysis of the small grey, metallic nugget produced from test #15 was confirmed to contain zones of

elemental silicon. The purity of this material was at least 99.9%, considering the precision of the

equipment.

The interface material between carbon and silicon was identified as silicon carbide, indicating its role as

an intermediate reaction product.

Chemical and morphological results suggest that significant reaction occurs inside the pores of the

carbon. Gaseous silicon monoxide, from the decomposition of quartz at high temperature, is

hypothesized to diffuse into the pores and to form pure silicon.

In future experiments we recommend investigation of the effect of carbon materials of different

porosity on silicon production.

1605061


Inc. Any copy, reproduction, distribution or use of this document, in whole or in part, which has not previously been approved in writing by PyroGenesis Canada Inc. is strictly forbidden.

7PYROGENE515

Document Type Technical Memo Document Title Mass balance on impurities Document No. Rev. No. Issue Date(YYYY-MM-DD) Page

TM-2016-758 C ._ 7J-..,,is- , _ 1 of 4

J

Quartz Refining

IPN No.: 2931

TM-2016-758, Rev. 01

Technical Memo

Mass Balance on Impurities

Distribution List

~ '`~ t-1~

13 IAA. Ë jt+

p~nc .TiON ,„ ~L= C •i

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Name Organisation Coordinates

Bernard Tourillon HPQ Resources [email protected]

Patrick Levasseur HPQ Resources [email protected]

Approvals Name Signature

Prepared by: Christopher A. Dion, Eng., M.A.Sc. % %/ ̀

Checked by: Pierre Carabin, Eng., M.Eng.

Revision List

Revision No. Date By Description

00 2016-09-19 CADD Initial Release

01 2016-09-23 CADD Corrected Power Density Values, See ** in

table 3 for more details.

PyroGenesis Canada Inc., 1744 William Street, Suite 200, Montréal (Québec), H3J 1R4, Canada,

Phone: +1-514-937-0002, Fax: +1-514-937-5757, Email: plasma @pyrogenesis.com

© 2016, PyroGenesis Canada Inc.



iPYROGENESIS

Document Type Technical Memo Document Title Mass balance on impurities Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM-2016-758 r, - 2 of 4

1.0 Summary tables ~ ̀3 JAN, - ; i~"ONGÉr.ÉRa!EDELA

DU M!~;n ~ MiNfER

Table 1- Summary of the test conducted during the Proof of Concept testing phase

Test (#) Date Description Result

Analysis

Available (Y/N)

1 2016-03-29 First test hot test No sample produced N

2 2016-04-07 Increased power input sample produced N

3 2016-04-08 Reduced heat losses Test Failure N

4 2016-04-15 Changed electrode tip Test Failure N

5 2016-04-20 New electrode sealing Test Failure N

6 2016-05-09 New electrode design Sample produced Y

7 2016-05-10 Additional Insulation Sample produced Y

8 2016-05-13 Changed C particle size Test Failure N

9 2016-05-13 Pre-dried carbon source Sample produced Y

10 2016-05-25 Changed base design Sample produced Y

11 2016-05-30 Changed base design No sample produced N

12 2016-06-16 Smaller Quartz particle size No sample produced N

13 2016-07-05 Mixture of quartz particle size

Traces of metal

produced N

14 2016-07-13 Reproduce previous test

Traces of metal

produced N

15 2016-07-22 Improve heat losses Sample produced Y

16 2016-09-02 Conventional non-vacuum arc No sample produced N

Table 2 - Impurities level of source materials

Elements Quartz Graphite

Roncevaux Martinville 4055 5559

(-) (%) (PPm) (%) (PPm) (V) (PPm) (i6) (PPm) Al 0.0215 215 0.00294 29.4 0.0178 178 0.0253 253

B 0.003958 39.58 0.003233 32.33 0.0000 0.35 0.0003 2.80

Ca 0.0028 28 0.00159 15.9 0.0052 52 0.2196 2196

Fe 0.0083 83 0.00265 26.5 0.0138 138 0.0040 40

P 0.0017 17 0.0012 12 0.0003 3 0.0207 207

S 0 0 0 0 0.0011 11 0.0250 250

Ti 0.0005 5 0.0001 1 0.0005 5 0.0002 2



7PYROGENE515

Document Type Technical Memo Document Title Mass balance on impurities Document No. Rev. No. Issue Date(YYYY-MM-DD) Page TM-2016-758 00 2016-09-23 3 of 4

Table 3 - Summary of conditions of the tests for which a sample was produced and analyzed

Test Quartz Graphite Mass* Power Time Density**

(#) (source) (source) (g) (kW) (min) kW*h/kg

6 Martinville 4055 252.4 2 30 3.96

7 Martinville 4055 210.0 2.3 22 4.02

9 Martinville 5559 221.6 2.15 30 4.85

10 Martinville 5559 181.7 2.2 12 2.42

15 Martinville 4055 397.3 3 45 5.66

* Total moss for a fixed weight ratio of 2.5:1 Si02:C

** Power Densities were off by a factor of 10 in Rev00 of this same document.

Table 4- Impurity removal efficiencies for tests conducted with 5559 as graphite source

Elements Test #9 Test #10

In (ppm) Out (ppm) diff (%) In (ppm) Out (ppm) cliff (%)

Al 93.4 1.7 98% 93.4 2.7 97%

B 23.9 2.1 91% 23.9 4 83%

Ca 639.5 5.1 99% 639.5 25 96%

Fe 30.3 95 -214% 30.3 75 -148%

P 67.7 22 67% 67.7 15 78%

S 71.5 , 33 54% 71.5 14 80%

Ti 1.3 16 -93% 1.3 2 -49%

Table 5 - Impurity removal efficiencies for tests conducted with 4055 as graphite source

Elem. Test #6 Test #7 Test #15

In(ppm) Out(ppm) cliff (%) In(ppm) Out(ppm) dill (%) In(ppm) Out(ppm) dill (%)

Al 71.8 10 86% 71.8 3.2 96% 71.8 19 74%

B 23.2 0.58 97% 23.2 0.45 98% 23.2 1 96%

Ca 26.1 23 12% 26.1 20 23% 26.1 4.7 82%

Fe 58.4 180 -208% 58.4 23 61% 58.4 54.5 7%

P 9.5 0.55 94% 9.5 0.31 97% 9.5 0.73 92%

S 3.1 1300 -42506% 3.1 680 -22186% 3.1 1055 34476%

Ti 2.0 8.5 -321% 2.0 3.3 -63% 2.0 3.9 -93%



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PYROGENESIS

Document Type Technical Memo Document Title Mass balance on impurities Document No. Rev.No. issue Date(YYYY-MM-DD) Page

TM-2016-758 0 -:0>;_ - , ' :-. 4 of 4

Table 6 — Impurity removal summary for all tests, ignoring Sulfur as a contaminant

Elem.

Impurity removal per test

#6 #7 #9 #10 #15

Al 86% 96% 98% 97% 74%

B 97% 98% 91% 83% 96%

Ca 12% 23% 99% 96% 82%

Fe -208% 61% -214% -148% 7%

P 94% 97% 67% 78% 92%

Ti -321% -63% -93% -49% -93%

2.0 Interpretation of the results

The results as shown in Table 4 and Table 5 seem to indicate that generally speaking the PureVap

concept works. Removal efficiency for Al, B, Ca and P were consistently high, between 67 and 97 % for

tests #6, #7, #9, #10 and #15. Less consistent results were obtained for Fe, which had some good

removal efficiency in tests #7 and #15, but seem to show accumulation in tests #6, #9 and #10. Such

differences cannot be explained for now.

The picture is different for Ti, which has gained in concentration during the tests. This can be explained

by the fact that Titanium has a very low partial pressure; however, B which has an even lower partial

pressure did not show the same behaviour. It is possible that another phenomenon is occurring.

In Table 5, the samples produced with the 4055 carbon show very high level of sulphur. The idea that

the sample gained in sulphur during the test does not make sense, as it is an element that is relatively

easy to vaporize and therefore should not gain in concentration. Therefore, it can be deduced that the

carbon was probably contaminated somehow and that the analysis from the laboratory do not

correspond to the carbon used anymore. Further investigation is required to characterize and eliminate

this source of sulphur. It is unlikely that the contamination of carbon is due to the PureVap process

itself. It is therefore too early to pronounce a statement regarding the efficiency of the PureVap to

remove Sulphur.

Finally, Table 6 is a compilation of all the 5 tests for which a complete analysis is available. This table

compiles the removal efficiencies of the most common impurities, except the sulphur which was ignored

for the reason mentioned above.

In conclusion, the results seem to confirm that the PureVap Process works very well to remove Al, B, Ca

and P, but not so well with Fe and not at all for Ti. It is too early to make a statement regarding S,

although removing S by evaporation should not be an issue in theory.



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