SRG Graphite Inc. (TSX-V: SRG) is pleased to announce results of a Preliminary Economic Assessment study for the development of its Lola graphite project in the Republic of Guinea, West Africa. The PEA was prepared by Montréal-based Met-Chem, a division of DRA Americas Inc. All dollar figures are in United States dollars.
Highlights of the Lola graphite PEA:
“These results highlight the value of the Lola graphite asset for the company” said Ugo Landry-Tolszczuk, President and Chief Operating Officer of SRG, “that said, the team will continue to work on improving the design and economics of the project. During our trade-off assessment work, we have found several key points of improvement to incorporate in the feasibility study. Early works which will contribute to the next stage in the development of the project is underway and we are dedicated to meeting our objectives for the year.”
The PEA follows the Mineral Resource Estimate published on June 18, 2018. A technical report detailing the PEA, and completed in accordance with National Instrument (NI) 43–101 guidelines, will be filed and available on SEDAR within 45 days from June 18, 2018, the release date of the mineral resource update published by the Company. Effective date of the estimate is June 14, 2018.
COMMERCIAL SALES, REVENUES & PROJECT ECONOMIC SENSITIVITIES
The Lola mine will produce an average of 50,200 tonnes of saleable graphite annually. At an average sale price of $1,328 per tonne, this represents $66.6M annual revenue. Given the volatility of graphite prices in recent years and the bilateral nature of sales contracts a sensitivity analysis of the project economics is presented below in Table 1.
|Table 1 Project economics sensitivity analysis (pre-tax)|
|Average Sale Price ($/t)||1,195||1,261||13281||1,394||1,460|
|Average annual revenue (million)2||60.0||63.3||66.6||70.0||73.3|
|Average annual cash flow (million) 2||31.2||34.5||37.9||41.2||44.5|
|NPV (million) @ 8% discount||151||177||204||231||257|
|Average annual cash flow (million) 2||22.7||25.0||27.3||29.5||31.8|
|NPV (million) @ 8% discount||84||102||121||139||157|
|2||Does not include year 16 as it is not a full year|
MINERAL RESOURCES UPDATE
The PEA was prepared using data from the Mineral Resource Estimate published on June 18, 2018, and including the latest drill campaign. To maximize the life of mine of the project, the PEA uses the resource at a cut-off grade of 1.64% graphitic carbon (“Cg”), which includes measured resources of 2.1 million tonnes (“Mt”) grading 4.31% Cg, indicated resources of 17.0Mt grading 4.39% Cg and inferred resources of 2.1Mt grading 4.79% Cg. The resource has been pit-constrained at $1,300/t. Figure 1 depicts the resource locations on the deposit and represents approximately 30% of the deposit outline.
Figure 1 Map of the Deposit With Resource Classification
The mineral resources update was estimated as at June 14, 2018, in accordance with the definitions adopted by the Canadian Institute of Mining Metallurgy and Petroleum and incorporated into National Instrument 43-101 – Standards of Disclosure for Mineral Projects (NI 43-101). Mineral resources estimate update for the Lola graphite project was carried out by Dr. Marc-Antoine Audet, P.Geo., Lead Geologist and SRG’s Qualified Person.
The Lola deposit is characterised by its saprolite surface mineralisation, which continues at depth into the fresh rock bed. For the PEA, mining operations were exclusively focused on the weathered zone, ensuring operation efficiency and competitive cost of operations. The first 30 metres of the deposit represent the weathered material. Constraining mining to the weathered portion of the deposit ensures minimal utilisation of blasting, and results in a strip ratio of only 0.39.
The average grade fed to the processing plant over the 16-year mine life is 4.43% Cg, and the total material mined per year is 1.8Mt (mineralised material and waste). Mining costs were established at 2.13$/t, considering preliminary pit design and access roads.
|Table 2 Mining highlights|
|Mining costs ($/t material mined)||2.13|
|Average graphite grade (% Cg)||4.43%|
|Stripping ratio (waste/mineralised)||0.39|
|Average graphite bearing material mined per year (t/y)||1,294,763|
|Average waste mined per year (t/y)||510 178|
|Mine of Life (years)||16 years|
The processing plant and waste dump are located on a plateau, west of the main pit, where the land is already conveniently flat and barren of trees. It is currently less than one kilometre from the visual mineralisation. This proximity will ensure short cycle times and contribute to the control of production costs.
Efforts were made to keep a simple flowsheet with limited polishing and flotation stages. Concentrate grade higher than 94% Cg is expected, with a recovery of 79%. Reagents used for processing are diesel as a collector and methyl isobutyl carbinol (“MIBC”) as a frother, both commonly available and routinely used reagents in the graphite sector. The processing costs are $9.24/t of processed material resulting in $248/t of graphite concentrate produced. Table 3 provides a summary of results.
|Table 3 Process highlights|
|Processing costs ($/t plant feed)||9.24|
|Processing costs ($/t concentrate)||248|
|Average concentrate grade (%Cg)||>94%|
|Graphite plant recovery||79%|
|Average material fed to the plant (t/year)||1,294,763|
Mineralised material handling, crushing, scrubbing, grinding and de-sliming circuits were designed considering the saprolitic properties of the deposit. The relatively low competency of the material allows the design to use two mineral sizers at the front end instead of a jaw crusher or cone crusher. These processing units are known for their low operational cost and reliability compared with conventional jaw and cone crushers.
The crushed material is fed into a scrubber which promotes flake preservation and consumes less energy compared with conventional milling methods. The scrubber discharge is screened, where the coarse fraction is fed to a closed-circuit ball mill, before being recombined with the screen fines. The combined slurry is then fed through a de-sliming stage, where ultra-fines, including slime, clay and organic material are removed. This leads to an upgraded and cleaner material feeding the flotation circuit, resulting in an overall simpler flowsheet.
After de-sliming, the material is fed to the rougher flotation bank producing a rougher concentrate. A first polishing stage further liberate the graphite flakes. The polished rougher concentrate goes through a first cleaning stag and is then fed into a splitting screen, dividing the fine from the coarse graphite, in order to apply the relevant specific polishing energy to each stream. After their respective polishing and cleaning stages, the two streams are recombined, thickened, filtered and dried. The dried concentrate is then screened into four different size fractions before being bagged, and finally stored and shipped to clients.
Figure 2 Process flowsheet
Quality Control and Assurance
Silvia Del Carpio, P.Eng., MBA Met-Chem/DRA., independent Qualified Person as defined by National Instrument 43-101, for the purposes of the PEA has reviewed the technical content of this press release. Raphaël Beaudoin P. Eng., Director of Operations and a Qualified Person for SRG has read and approved this press release.
The PEA completed for the Company is preliminary in nature and includes inferred mineral resources, considered too speculative in nature to be categorized as mineral reserves. Mineral resources that are not mineral reserves have not demonstrated economic viability. Additional trenching and/or drilling will be required to convert inferred mineral resources to indicated or measured mineral resources. There is no certainty that the resources development, production, and economic forecasts on which this PEA is based will be realized.
Met-Chem, a division of DRA Americas Inc., was originally established in 1969 as a consulting engineering company, headquartered in Montreal, and provides a wide range of technical and engineering services. Met-Chem is well recognized for its capabilities in mining, geology and mineral processing and has a talented team of engineering, technical and project management personnel with experience in North America, Latin America, Europe, West Africa and India. DRA is a multidisciplinary global engineering group that originated in South Africa and delivers mining, mineral processing, energy, water treatment and infrastructure services from concept to commissioning, as well as comprehensive operations and maintenance services for the mineral resources, water, agriculture and energy sectors. DRA has offices in Africa, Australia, Canada, China, India and the United States.
SRG is a Canadian-based company focused on developing the Lola graphite deposit and the Gogota nickel-cobalt-scandium deposit, both located in the Republic of Guinea, West Africa. SRG is committed to operating in a socially, environmentally and ethically responsible manner.
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