Investor Call to be held on Monday August 20^th, 2018 at 11:30 a.m. (EST). 

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Participant Code: 642381#
São Paulo +55 (11) 3230-2305
New York: +1 (917) 338-1451
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Webinar Link: https://sigmalithium.clickmeeting.com/sigma-lithium-resources

VANCOUVER, British Columbia, Aug. 16, 2018 (GLOBE NEWSWIRE) -- SIGMA Lithium Corporation ("Sigma" or the "Corporation") (TSX-V: SGMA) announces today the commissioning of the Phase 1 production plant on its property site in Minas Gerais, Brazil. This is a very significant step towards achieving full-scale commercial production at its Grota do Cirilo Property – targeted for the fourth quarter of 2019.

Sigma is also pleased to provide an update on the 2018 drilling campaign of its lithium deposits at its Grota do Cirilo Property, including the assay results received to date. Sigma’s diamond drilling campaign of ˜30,000 meters is well underway and on track to achieve the goal of increasing  the existing measured, indicated and inferred lithium mineral resources of 13,5 million tonnes  to 37 million tonnes, validating the additional exploration potential previously identified in Sigma’s existing National Instrument 43-101 Independent Technical Report (“NI 43-101”) filed earlier in 2018.

Commissioning of Lithium Concentrate Phase 1 Production Plant

Sigma has commissioned its phase 1 production plant which includes a cost effective Dense Media Separation (DMS) process circuit. The plant is designed to produce a high-quality battery-grade coarse spodumene concentrate with 6% Li₂O.

The production plant is modular and is expected to initially produce 12,000 tonnes of lithium spodumene concentrate per year. The plant has a two-stage crushing circuit with a capacity of 60 tonnes per hour (doubled from the original design). The DMS unit produces two coarse fractions of concentrate of +4mm to -10mm and +10mm to -20mm. Sigma continues to test ore sorter technologies, in order to include an ore sorter as a first stage module of the production plant, to further increase its downstream capacity in the future.

The production plant is being commissioned with the aim of finalizing offtake agreements with potential clients and partners. The spodumene concentrate produced from the plant will be used as large size samples in Sigma’s ongoing offtake discussions.

“We are very pleased to commission this phase I production plant,” said Calvyn Gardner, CEO of Sigma. “Having built this facility now showcases our battery-grade concentrate and enables us to ship samples to potential strategic partners. This will position us to finalize offtake agreements well before we are in commercial production in 2019.”

Advancing the Definitive Feasibility Study Blasting a 200 Tonnes Bulk Sample at Xuxa deposit

Sigma is also pleased to announce that it opened two large trenches in the Xuxa deposit and blasted approximately 7,000 tonnes of material. A bulk sample of approximately 200 tonnes was produced from the Xuxa deposit for the additional metallurgical testing required for the completion of its definitive feasibility study.

The 200 tonnes sample was removed from two large trenches opened across the width of the pegmatite. Trench 1 was opened where the historical drill assays showed 1.64% Li₂O (DH Xuxa-1) and trench 2 was opened where the assays showed 1.58% Li₂O (DH Xuxa-5) and 1.70% Li₂O (DH Xuxa-6). A second bulk sample of approximately 6 tonnes of drill core material was also produced. This sample has been collected across the deposit, as part of an ongoing diamond drilling program at Xuxa of ˜5,000 meters. The goal of the program is to produce a representative sample that will be processed at SGS Lakefield facilities in Ontario, defining design criteria for the metallurgical portion of the definitive feasibility study and for the commercial production plant design.

"We are on schedule to have the definitive feasibility study level 3 completed by January 2019,” commented Itamar Resende, President of Sigma Mineração, the Corporation’s Brazilian subsidiary. “This study is one of the key milestones for Sigma to achieve commercial production, as our large-scale plant design will be finalized based on the results of this study. Once we complete it, the only remaining step will be the detailed engineering.”

Reporting Drill Results to Date on Grota do Cirilo Lithium Property

Sigma is pleased to provide an update on the progress of the comprehensive drilling campaign underway at the Grota do Cirilo Property. The assay results received to date further validate the project’s mineral resource estimates provided in Sigma’s NI 43-101. They also outline the potential for the total resource volume to be significantly increased.

In late May 2018, the Sigma team commenced a diamond (HQ core) drilling campaign of ~30,000 meters to extend and develop the existing Grota do Cirilo spodumene lithium mineral resource. Once completed, this drilling campaign will be the basis for a revised mineral resource estimate, to be prepared by SGS Canada Geostat (“SGS”), which is expected to be finalized by the end of 2018.

The drilling program is divided into two work streams:

• A drilling program of 5,000 meters for the definitive feasibility study of the Xuxa deposit, Sigma’s cornerstone mine. The drilling consists of 25 holes focusing on: (i) increasing the size of the mineral resource, (ii) producing metallurgical samples at depth and (ii) conducting geotechnical studies;
• A definition drilling campaign of 25,000 meters for the additional four lithium deposits in the property (Barreiro, Lavra do Meio, Murial and Nezem do Chicao) contemplating drilling 72 holes at Barreiro, 19 at Lavra do Meio, 25 holes at Murial and 3 holes at Nezem do Chicao

Calvyn Gardner added, “This drilling campaign has been an unmitigated success thus far. Given our progress to date, we believe our goals of significantly increasing the mineral resource at Xuxa and increasing its mine life are both quite achievable. In addition, the positive assay results of the other deposits of Grota do Cirilo we have received to date demonstrate the potential for Sigma to become a significant participant in the global lithium industry.”

The drilling assays received to date from the definition drilling campaign for three of the lithium deposits (Xuxa, Barreiro and Lavra do Meio) are as follows:

1. Xuxa

• The Xuxa drilling campaign contemplates 25 holes (˜5,000 meters), of which 16 have been completed, totaling 2,998 meters at an average depth of 187 meters. Sigma has received 16% of the assays results to date and the current results indicate the potential to increase the level of confidence of mineral resources between 0 and 200 meters vertical from the surface.
  
  
• All the assays currently received demonstrate the continuity of the mineralization down to 200 meters and in some cases even down to 285 meters. The expansion of the mineralized zone down to 200 meters at Xuxa will allow us to further upgrade the mineral resource, adding additional volume. The geological 3D model is currently being updated, while the remaining assays are pending.
  
  
• Highlights from the Xuxa assays are:
  
  -  22.8 meters at 1.86% Li₂O in 5 veins, hold in 213.8 to 240.9 meters interval (drill hole DH-Xuxa - 67) 
  -  9.6 meters at 1.6% Li₂O from 134 to 143.6 meters (drill hole DH-Xuxa -68) 
  -  4.1 meters at 1.78% Li₂O from 192.6 to 196.7 meters (drill hole DH-Xuxa -68)
  -  19.9 meters at 1.86% Li₂O from 143.37 to 163.24 meters (drill hole DH-Xuxa 70)

2.    Barreiro

• The Barreiro drilling campaign contemplates 72 holes (˜10,800 meters), of which 55 holes have been drilled to date, for a total of 7,615m. Average thickness of the deposit is around 30m, the average drill hole depth is around 138m and deepest hole drilled to-date is 279m.
• Sigma received 30% of the assay results indicating that Barreiro could potentially become a significant world-class hard-rock deposit, on a similar scale to the Xuxa deposit.

Highlights from the Barreiro assays are:

-  36.1 meters at 1.50% Li₂O from 57.9 to 94 meters (drill hole DH-Bar-6)
-  29.4 meters at 1.80% Li₂O from 85.6 to 114.9 meters (drill hole DH -Bar-8)
-  33.8 meters at 1.62% Li₂O from 56.9 to 90.7 meters (drill hole DH-Bar-10)
-  37.0 meters at 1.53% Li₂O from 60.4 to 97.4 meters (drill hole DH-Bar 14)
-  21.5 meters at 1.56% Li₂O from 92.4 to 113.9 meters (drill hole DH-Bar 18)
-  41.9 meters at 1.88% Li₂O from 80.9 to 122.7 meters (drill hole DH-Bar 31)
-  22.4 meters at 1.62% Li₂O from 111.8  to 134.1 meters (drill hole DH-Bar 33)
-  37.1 meters at 1.62% Li₂O from 68.3 to 105.3 meters (drill hole DH-Bar 38)
-  38.0 meters at 1.79% Li₂O from 117.8 to 155.9 meters (drill hole DH-Bar 40)

3. Lavra do Meio

• The Lavra do Meio deposit is a 250 meters dyke dipping around 75 degrees to the east.
• The Lavra do Meio drilling campaign contemplates 19 drill holes (˜4,000 meters), of which 15 holes have been drilled to date for a total of 1,958 meters.  Sigma received 53% of the assay results.
• Average thickness of the deposit is around 20 meters and the average drill hole depth is around 131 meters and deepest hole drilled to date was 241 meters.

Highlights from the Lavra do Meio assays are:

• 27.6 meters at 1.78% Li₂O from 38.8 to 66.4 meters (drill hole DH-LDM-4)
• 31.9 meters at 1.31% Li₂O from 94.5 to 126.3 meters (drill hole DH-LDM-5)
• 38.5 meters at 1.30% Li₂O from 95.5 to 134 meters (drill hole DH-LDM-8)
• 22.8 meters at 1.14% Li₂O from 149.7 to 172.5 meters (drill hole DH-LDM-14)

The geological 3D model for the various deposits are currently being updated, while assays are pending.

The mineral estimation will be carried out by SGS. Samples are prepared and analyzed by SGS in their accredited laboratories in Lakefield, Canada and in Belo Horizonte, Brazil.

The following table sets out the assay results received to date for the 2018 drilling campaign:

The intervals reported in this table represent drill intercepts and insufficient data is available at this time to state the true thickness of the mineralized intervals.

Quality Control

QA/QC program involving blank samples (4% of the sampling stream), standard samples (4% of the sampling stream) and field duplicates (6% of the sampling stream) has been established during sampling. A further 6% of the mineralized samples will also be sent to the ALS Laboratory in Vancouver, Canada for pulp duplicates, once the campaign is over. All assays are analyzed at SGS’s Belo Horizonte, Brazil laboratory using a multi-elements peroxide fusion ICP-AES on half-core 1 kg sample selected by geologist.

INVESTOR CONFERENCE CALL

Sigma announces that it will hold an investor call on August 20^th, 2018 at 11:30 a.m. (EST). The Webinar link and dial-in instructions to participate in the call are as follows:

Webinar Link: https://sigmalithium.clickmeeting.com/sigma-lithium-resources

Dial in:
Participant Code: 642381#

São Paulo +55 (11) 3230-2305
New York: +1 (917) 338-1451
Toronto: +1 (647) 497-7729
Dial in from other locations: https://account-panel.clickmeeting.com/dialplan

ABOUT SIGMA

Sigma Lithium Corporation is developing in Minas Gerais, Brazil, a globally significant lithium hard rock project. Sigma commissioned its Phase I Production Plant and has commenced the production of battery-grade spodumene concentrate from its high-quality deposits. Sigma’s corporate mission is to execute its strategy while embracing environmental, social, and governance principles. The Corporation is on track to become an high quality lithium concentrate supplier to the battery industry worldwide.

Sigma shareholders include some of the largest ESG (environmental, sustainability, governance) focused institutional investors in the world. Sigma plans to commence construction of a commercial-scale lithium concentration plant in 2019, and to become a fully-operational sustainable lithium producer in 2020.

Sigma, through its subsidiaries, has 28 mineral rights in four properties spread over 188 km2 with over 200 lithium bearing pegmatites and 9 former historical lithium mines. The Grota do Cirilo property, Sigma’s primary focus, includes 10 mining concessions (mining production authorizations).

Sigma has a NI 43-101 technical report on the Grota do Cirilo property prepared by SGS, which includes estimated measured and indicated and inferred resources of approximately 13,500,000 tonnes for its main deposit (8,502,000t measured and 4,385,000t indicated), with a high average grade of 1.56%. The technical report also further notes the potential for significant resource expansion to 37 million tonnes.

QUALIFIED PERSON

The resources estimates in this news release are included in the technical report titled “Technical Report Northern and Southern Complexes Project, Araçuai and Itinga, Brazil, Sigma Lithium Resources Inc.” which has an effective date of January 29^th, 2018 and was prepared by Marc-Antoine Laporte, P.Geo, M.Sc. of SGS. Mr. Laporte is a qualified person as defined by NI 43-101 and is independent of Sigma.  The report is available at www.sedar.com. Mr. Laporte has also reviewed and approved the scientific and technical information in this news release.

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