Sigma Lithium — Regulatory Filings 2021

Jul 16, 2021

CERTIFICATE OF AUTHOR JACQUELINE WANG

I, Jacqueline Wang, P. Eng., do hereby certify:

1. I was a Process Engineer with Primero Group Americas Inc., a division of Primero Group Ltd. with an office at 1450 - 1801 McGill College, Montréal, Québec.

2. This certificate applies to the Technical Report entitled “Grota do Cirilo Lithium Project: Araçuaí and Itinga Regions, Minas Gerais, Brazil, Phase 2 (Barreiro) Update of the NI 43-101 Technical Report Feasibility Study” with an effective date of June 2, 2021.

3. I graduated with a Bachelor of Science degree in Chemical Engineering from the University of Saskatchewan, Saskatoon in 2008 and a Master of Engineering degree in Chemical Engineering from the University of Saskatchewan, Saskatoon in 2016.

4. I am a registered Professional Engineer (#15447) with the Association of Professional Engineers and Geoscientists in Saskatchewan.

5. I have worked as a process engineer since 2008.

6. I have read the definition of “qualified person” set out in the National Instrument 43-101 and certify that by reason of my education, affiliation with a professional association and past relevant work experience, I fulfil the requirements to be an independent qualified person for the purposes of NI 43-101.

7. I have no previous involvement with the project.

8. I have participated in the preparation of this Report and am responsible for Section 17, the applicable parts of sections 1, 2, 3, 25 and 26 and sub-sections 18.7, 21.5, 21.5.1, 21.5.2, 21.5.3, 21.5.4 and 21.5.5, I take responsibility for information related to Xuxa only.

9. As of the effective date of the Technical Report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make the technical report not misleading.

Signed and dated this July 15, 2021, at Saskatoon, Saskatchewan.

“ Signed and sealed ” Jacqueline Wang

Jacqueline Wang, P.Eng., Process Engineer Primero Group Americas Inc