Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon...

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9 The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release TSX: RMX | OTCQX: RBYCF Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After-Tax IRR and C$191 million Free Cash Flow Potential of the Phoenix Gold Project TORONTO, Ontario, August 19, 2019 – Rubicon Minerals Corporation (TSX: RMX | OTCQX: RBYCF) (“Rubiconor the “Company”) released a positive new Preliminary Economic Assessment 1 (“New PEA”) for the Phoenix Gold Project (the “Project”) demonstrating its strong free cash flow potential and robust estimated returns on capital. The New PEA has been prepared by T. Maunula and Associates Consulting Inc. (“TMAC” or “Consultants”) and the Company plans to file an updated technical report for the Project reflecting the New PEA, prepared in accordance with National Instrument 43- 101 of the Canadian Securities Administrators (“Technical Report”), on www.sedar.com within 45 days. This news release contains information from a preliminary economic assessment, which is a conceptual study, and other forward-looking information about potential future results and events. Please refer to the cautionary statements in the footnotes below and the Cautionary Statements located at the end of this this news release, which include associated assumptions, risks, uncertainties and other factors. New PEA Highlights: Table 1:Economic analysis summary (base case estimates) 1 Economic Analysis (base case estimates): Conceptual Project Life of Mine (“LOM”) After-tax Internal Rate of Return (“IRR”) (%) 40.2% After-tax Net Present Value 2 (“NPV5%”) (in Canadian dollars, “C$” or “CAD”) C$135.2 million After-tax free cash flow potential C$191.5 million Exchange ratio (U.S. dollars, “US$ or “USD”/C$) 0.7519 Gold price assumption (US$) US$1,325/payable troy ounce (“oz”) Gold price assumption (C$) C$1,762/oz Payback period 3.9 years Table 2: Conceptual LOM plan summary Conceptual LOM Plan Metrics: Total Per Unit Operating period (from potential initial production)(“LOM year”) 6.2 years - Commercial Production period 3 (“CP”) 5.1 years - Construction, development, commissioning and ramp-up to CP (“Pre-CP”) 20 months LOM tonnes milled (including Pre-CP tonnes)(“LOM tonne”) 3,045,196 1,370 tpd CP tonnes milled (“CP tonne”) 2,799,863 1,530 tpd LOM mill head grade (after external dilution, backfill and mining recovery) 4 5.31 g/t Au - Dilution (%) (external + backfill dilution)/mining recovery 14%/95% - LOM payable gold production (including Pre-CP oz)(“LOM oz”) 493,583 oz 79,610 oz per LOM year 1 Cautionary Statement: The reader is advised that the New PEA summarized in this press release is only a conceptual study of the potential viability of the Project’s mineral resource estimates, and the economic and technical viability of the Project and its estimated mineral resources has not been demonstrated. The New PEA is preliminary in nature and provides only an initial, high-level review of the Project’s potential and design options; there is no certainty that the New PEA will be realized. The New PEA conceptual LOM plan and economic model include numerous assumptions and mineral resource estimates including Inferred mineral resource estimates. Inferred mineral resource estimates are considered to be too speculative geologically to have any economic considerations applied to such estimates. There is no guarantee that Inferred mineral resource estimates will be converted to Indicated or Measured mineral resources, or that Indicated or Measured resources can be converted to mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability, and as such there is no guarantee the Project economics described herein will be achieved. Mineral resource estimates may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant risks, uncertainties and other factors, as more particularly described in the Cautionary Statements at the end of this news release. 2 Calculated at a 5% discount rate. 3 Conceptual Commercial Production is defined as 70% of 1,250 tonnes per day (“tpd”) permitted capacity over 60 consecutive days. Cash costs, sustaining capital, operating costs and all-in sustaining costs are calculated from the start of CP. 4 Based on a 3.5 grams per tonne of gold (“g/t Au”) conceptual mining cut-off grade.

Transcript of Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon...

Page 1: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

TSX: RMX | OTCQX: RBYCF

Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After-Tax IRR and C$191 million Free Cash Flow Potential of the Phoenix Gold Project

TORONTO, Ontario, August 19, 2019 – Rubicon Minerals Corporation (TSX: RMX | OTCQX: RBYCF) (“Rubicon” or the “Company”) released a positive new Preliminary Economic Assessment1 (“New PEA”) for the Phoenix Gold Project (the “Project”) demonstrating its strong free cash flow potential and robust estimated returns on capital. The New PEA has been prepared by T. Maunula and Associates Consulting Inc. (“TMAC” or “Consultants”) and the Company plans to file an updated technical report for the Project reflecting the New PEA, prepared in accordance with National Instrument 43-101 of the Canadian Securities Administrators (“Technical Report”), on www.sedar.com within 45 days. This news release contains information from a preliminary economic assessment, which is a conceptual study, and other forward-looking information about potential future results and events. Please refer to the cautionary statements in the footnotes below and the Cautionary Statements located at the end of this this news release, which include associated assumptions, risks, uncertainties and other factors. New PEA Highlights: Table 1:Economic analysis summary (base case estimates)1

Economic Analysis (base case estimates): Conceptual Project Life of Mine (“LOM”) After-tax Internal Rate of Return (“IRR”) (%) 40.2%

After-tax Net Present Value2 (“NPV5%”) (in Canadian dollars, “C$” or “CAD”) C$135.2 million

After-tax free cash flow potential C$191.5 million Exchange ratio (U.S. dollars, “US$ or “USD”/C$) 0.7519

Gold price assumption (US$) US$1,325/payable troy ounce (“oz”) Gold price assumption (C$) C$1,762/oz

Payback period 3.9 years Table 2: Conceptual LOM plan summary

Conceptual LOM Plan Metrics: Total Per Unit Operating period (from potential initial production)(“LOM year”) 6.2 years -

Commercial Production period3 (“CP”) 5.1 years - Construction, development, commissioning and ramp-up to CP (“Pre-CP”) 20 months

LOM tonnes milled (including Pre-CP tonnes)(“LOM tonne”) 3,045,196 1,370 tpd CP tonnes milled (“CP tonne”) 2,799,863 1,530 tpd

LOM mill head grade (after external dilution, backfill and mining recovery)4 5.31 g/t Au - Dilution (%) (external + backfill dilution)/mining recovery 14%/95% -

LOM payable gold production (including Pre-CP oz)(“LOM oz”) 493,583 oz 79,610 oz per LOM year

1 Cautionary Statement: The reader is advised that the New PEA summarized in this press release is only a conceptual study of the potential viability of the Project’s mineral resource estimates, and the economic and technical viability of the Project and its estimated mineral resources has not been demonstrated. The New PEA is preliminary in nature and provides only an initial, high-level review of the Project’s potential and design options; there is no certainty that the New PEA will be realized. The New PEA conceptual LOM plan and economic model include numerous assumptions and mineral resource estimates including Inferred mineral resource estimates. Inferred mineral resource estimates are considered to be too speculative geologically to have any economic considerations applied to such estimates. There is no guarantee that Inferred mineral resource estimates will be converted to Indicated or Measured mineral resources, or that Indicated or Measured resources can be converted to mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability, and as such there is no guarantee the Project economics described herein will be achieved. Mineral resource estimates may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant risks, uncertainties and other factors, as more particularly described in the Cautionary Statements at the end of this news release. 2 Calculated at a 5% discount rate. 3 Conceptual Commercial Production is defined as 70% of 1,250 tonnes per day (“tpd”) permitted capacity over 60 consecutive days. Cash costs, sustaining capital, operating costs and all-in sustaining costs are calculated from the start of CP. 4 Based on a 3.5 grams per tonne of gold (“g/t Au”) conceptual mining cut-off grade.

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Conceptual LOM Plan Metrics: Total Per Unit Payable gold production during CP (“CP oz”) 449,536 oz 88,675 oz per CP year

Payable gold during Pre-CP (“Pre-CP oz”) 44,047oz - Total stopes 341 8,930 LOM tonnes/stope

Bulk mining stopes 281 10,031 LOM tonnes/stope Cut-and-fill stopes 60 3,774 LOM tonnes/stope

Gold recoveries/via gravity 95.0%/43.0% Numbers may not add due to rounding

Table 3: Conceptual LOM capital and operating cost summary (base case estimates)

Capital and operating cost estimates: Total (millions) Per Unit Per Ounce

Capital cost estimates: (A) Initial Capital (including 15% contingency) (Pre-CP) C$101.2 - - (B) Capitalized Pre-CP operating cost C$45.7 C$186.2/pre-CP tonne US$780/pre-CP oz (C) Royalties (3%) and other production taxes5 (Pre-CP) C$3.0 C$12.2/pre-CP tonne US$51/pre-CP oz (D) Proceeds from sale of Pre-CP oz C$77.5 - - (E) Net Pre-CP operating cash flow: (D) – (B) – (C) C$28.8 - -

Net Pre-CP Capital: (A) - (E) C$72.4 - - Projected Funding Requirement6 C$80.9 - -

(F) Sustaining Capital (CP) C$154.0 C$30 million/CP year US$258/CP oz (G) Total LOM capital expenditures: (A) + (F) C$255.2 C$41 million/LOM year US$389/LOM oz

Operating cost estimates: Mining C$268.4 C$88.1/LOM tonne US$409/LOM oz Processing C$99.6 C$32.7/LOM tonne US$152/LOM oz Site G&A C$23.8 C$7.8/LOM tonne US$36/LOM oz (H) Total conceptual LOM operating costs C$391.8 C$128.7/LOM tonne US$597/LOM oz (I) Total commercial operating costs (CP): (H) – (B) C$346.1 C$123.6/CP tonne US$579/CP oz (J) Royalties (3%) and other production taxes7 (CP) C$26.9 C$9.6/CP tonne US$45/CP oz (K) Total Cash Costs (CP): (I) + (J) C$373.0 C$133.2/CP tonne US$624/CP oz (L) All-in sustaining costs8 (“AISC”)(CP): (F) + (K) C$527.1 C$188.2/CP tonne US$882/CP oz (M) All-in costs (“AIC”): (G) + (H) + (C) +(J) C$677.0 C$222.3/LOM tonne US$1,031/LOM oz

Taxes: Existing tax loss pools C$690 Estimated remaining tax loss pools after conceptual LOM C$521

Numbers may not add due to rounding

Key Takeaways from the New PEA:

• New PEA economics1 benefits from more than C$770 million in sunk capital in place, including a fully-operational state-of-the-art mill, a 730-metre deep shaft and hoisting facility, and more than 14,000 metres (“m”) of developed mine workings;

• Most estimates and costs were derived from 5 years of test trial mining data at the Project, including actual numbers achieved during the 2018 test trial mining and 35,000-tonne bulk sample processing program (see November 29, 2018 news release for more details on the 2018 program);

• Early operating cash flow estimate of C$28.8 million during the Pre-CP period and expected application of tax loss pools over the LOM plan help drive estimated key metrics such as IRR and NPV, lower the Projected Funding

5 Includes community payments. 6 Based on cumulative net cash flow analysis, factoring in the timing of capital, operating costs, and proceeds from gold sales. C$80.9 million represents the largest net cash flow deficit during the conceptual LOM. 7 Includes community payments. 8 All-in sustaining costs are presented as defined by the World Gold Council, including C$7.7 million of closure costs but excluding corporate G&A.

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Requirement, and conceptual LOM free cash flow potential1; and • Potential to increase mineral resource estimates with further diamond drilling and engineering studies and expand

the conceptual LOM plan with further engineering studies. Path Forward:

• Updated mineral resource estimate anticipated to be delivered in fourth quarter of 2019; and • Commence additional feasibility work in the first half of 2020.

CEO’s Comments Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA represents a significant milestone in demonstrating the free cash flow generating potential of the Phoenix Gold Project, using prudent assumptions. We are confident that this potential can be achieved in the near-term due to the very manageable Projected Funding Requirement, the new, fully-functional infrastructure at site, and the realistic cost and capital estimates outlined in the New PEA, which is below the cost of a similar greenfield project.” “We believe that the New PEA has a lower margin of error and risk because the estimates we used were derived from five years of operating data at the Project, including actual results achieved in our 2018 test trial mining and 35,000-tonne bulk sample processing program. The New PEA reflects a purposeful focus on rigor and prudence as the foundation for the potential construction and operation of the Project, following the prospective completion of a potentially positive feasibility study. We believe readers will view this New PEA as a well-designed, comprehensive plan put together under the direction of a management team and Consultants with successful and extensive underground mine construction, operational, and turnaround experience.” “Early positive cash flow forecasts during Pre-CP and the application of tax loss pools helps drive the after-tax IRR to 40.2% and lower the Projected Funding Requirement. In addition, the Project benefits from a strong leverage to the Canadian dollar gold price; the conceptual Project economics are even more compelling at the current Canadian dollar gold price of C$2,008 (or US$1,5139) per ounce. Please refer to Table 10 on page 8 of this news release to see the positive impact of a long-term gold price of US$1,500 per ounce on the IRR and NPV estimates for the Project. Furthermore, a sustained higher gold price environment translates to potentially adding more stopes in the conceptual LOM plan, which could manifest in further improvements to the Project’s forecast IRR and NPV.” “We believe an opportunity to enhance the Project is through the potential expansion of mineral resource estimates at depth and along strike. We have identified Explore Target areas10 of approximately 0.9 to 1.2 million tonnes of sparsely-drilled mineralized material grading 5.0 to 7.0 g/t Au that could potentially be added to the mineral resource estimates with future infill drilling. In addition, we have targets within two kilometres (“km”) of the Project that we plan to drill in the near future to potentially provide incremental gold ounces that could further upgrade the potential economics of the Project and extend its conceptual mine life. Other opportunities to potentially improve the Project include evaluating the expanded utilization of raise mining with mass blasts, a method which reduces stope cycle time and costs, evaluating ore-sorting technology to potentially improve mill head-grade, and the use of electric underground trucks to reduce ventilation costs.” 2019 Mineral Resource Estimate – New PEA Conceptual LOM Conversion1 The 2019 Mineral Resource Estimate (“2019 MRE”)11 for the Project (see Table 4 on page 11 of this news release) provided the basis for the New PEA conceptual LOM plan. In the 2019 MRE, the Company observed a robust conversion of Inferred 9 As of August 16, 2019, at 5:00pmET. Source: www.Kitco.com. 10 The potential quantity and grade of these Explore Target Areas are conceptual in nature. There has been insufficient exploration of the Explore Target areas to define a mineral resource estimate and it is uncertain if further exploration will result in any part of these target areas being delineated as a mineral resource. 11 2019 MRE is based on a 3.0 g/t Au cut-off grade. For further details, please review the Rubicon news release dated March 29, 2019 and Technical Report filed on www.sedar.com on April 25, 2019, which includes information on different cut-off grade sensitivities, including mineral resource estimates at a 3.5 g/t Au cut-off grade.

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

mineral resource estimates to Measured and Indicated mineral resources. Factoring in New PEA assumptions on gold price, foreign exchange, mining recovery, external and backfill dilution, mill recovery, and operating costs, the New PEA contemplates a conceptual mining cut-off grade of 3.5 g/t Au. Table 5 below outlines the conceptual conversion estimates applied towards the tonnes and the diluted mill head grade in the New PEA conceptual mine plan based on the 3.5 g/t Au cut-off: Table 5: Conceptual conversion of 2019 MRE using a 3.5 cut-off grade sensitivity12

Categories

2019 MRE using a 3.5 g/t cut-off grade sensitivity

New PEA Conceptual LOM plan (@ 3.5 g/t Au mining cut-off grade) Net

conversion of tonnes Tonnes In situ grade

(g/t Au) Tonnes Mill head grades (g/t Au)

Measured & Indicated 2,289,000 7.11 1,561,000 5.23 68.2% Inferred 2,038,000 7.39 1,484,300 5.39 72.8%

Numbers may not add due to rounding. Tonnes were rounded and may not add up to LOM tonnes

The Company believes this estimated conversion of tonnes to the New PEA conceptual mine plan is a function of rigor and prudence. The New PEA contemplates mining 341 conceptual stopes. The Company and its Consultants identified an additional 359 conceptual stopes that fell below the 3.5 g/t Au cut-off grade and could potentially be included in a future conceptual LOM plan with further engineering, infill diamond drilling, and higher gold price assumptions. The conceptual LOM plan predominantly focuses on mineral resource estimates within the high-titanium basalt units (“High-Ti Basalt”), the main host rock for gold mineralization. The strong competency of the High-Ti Basalt units enabled the Company to limit external dilution, as was seen during the 2018 test trial mining program. The F2 Gold Deposit remains open at depth and along strike. Furthermore, Rubicon has identified Explore Target areas11 (drilling greater than 80-m centres) where the Company intends to infill diamond drill. Please see Diagram 1 on page 13 of this news release for a longitudinal section of Zone 2 of the F2 Gold Deposit. The Company is also evaluating the McFinley and other close proximity targets, which are located within 2 km of the Project shaft and mill and could potentially result in additions to the current mineral resource estimates. Underground Development and Conceptual Mining The Rubicon management and site teams have extensive and successful mine operations and turnaround experience. The Company successfully demonstrated this capability at the Project during the successful 2018 test trial mining and 35,000-tonne bulk sample processing program. The Company tested both the Sub-Level Longhole and Uppers bulk mining methods on the deposit, achieving an external dilution of 8.7%, and more importantly, delivered a positive reconciliation of the mill results with the block model. Cost and technical data generated during 5 years of underground development and test trial mining activities between 2013 and 2018 were foundational to the estimates used in the New PEA. Underground Development The Project benefits from more than 14,000 m of extensive developed mine workings and related site infrastructure. The Project has an operational shaft down to 730 m below the surface, with loading pockets located at the 337- and 610-m Levels. The shaft has a peak hoisting capacity of approximately 3,000 tonnes of material per day. The majority of the existing underground development, including lateral development, a partially completed ramp system, waste/ore passes, and ventilation raises, are primarily located between 122- and 305-m Levels. The New PEA contemplates 26,608 m of underground development (17,279 m lateral and ramp, and 9,329 m vertical) throughout the conceptual LOM plan. Approximately 6,000 m of underground development, including a ramp to surface,

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

is planned during Pre-CP, providing access to approximately 40 to 50 of working stopes. Rubicon believes this work could provide approximately 12 months of development flexibility. Peak development rates of 14 m (or 5 rounds) per day, using a maximum of 4 development crews, are expected to be achievable, especially once multiple headings have been opened up. Please see Diagram 2 on page 14 of this news release for an image of the conceptual underground development and stope shapes and Table 6 on page 11 of this news release for the conceptual LOM lateral and ramp development schedule. Mining Methods The amenability of bulk mining methods was demonstrated during the test trial mining program in 2018. The conceptual LOM plan contemplates mainly bulk mining methods. Please see Table 2 for a conceptual LOM plan summary. Four mining methods were contemplated: Sub-Level Longhole (bulk mining, 52.4%), Uppers (bulk mining, 23.3%), Mass Blasting Raise Mining (“MBRM”)(bulk mining, 16.9%) and cut-and-fill (selective mining, 7.4%). Table 7 below provides additional detail on these mining methods as contemplated in the conceptual LOM plan: Table 7: Mining methods contemplated for the New PEA Conceptual LOM (base case estimates)

Metrics Sub-Level Longhole Uppers MBRM Cut-and-Fill

Conceptual LOM tonnes 1,595,921 708,880 513,974 226,420 Conceptual LOM tonnes (%) 52.4% 23.3% 16.9% 7.4%

Total stopes 66 172 43 60 Average stope size (tonnes) 24,181 4,121 11,953 3,774

Average dimensions (height x width x strike) 36m x 8m x 25m 16m x 6m x 12m 37m x 3m x 22m 12m x 6m x 16m

External dilution12 10% 15% 10% 3% Average diluted grade

(after dilution and mining-loss) 5.34 g/t Au 5.30 g/t Au 5.31 g/t Au 5.16 g/t Au

Mining cost per tonne (including indirect costs) C$82.88 C$86.88 C$92.15 C$120.58

Typical productivity rates for these mining methods (tpd) 400 300 600 130

Numbers may not add due to rounding

Both the Sub-Level Longhole and Uppers method were successfully tested by the Company during the 2018 test trial mining program. The Uppers method involves drilling a stope with up-holes including a slot raise (between 16-20 m in length) from an under-cut drift without the development of an over-cut. See Diagram 3 on page 15 of this news release for a conceptual diagram of the Sub-Level Longhole and Uppers mining methods. An opportunity for the Project is the expanded use of MBRM. MBRM involves an Alimak access raise along the mineralization, with short horizonal drilling from the Alimak raise into the mineralization. The mineralized material is blasted from the short holes and mucked out in the under-cut. MBRM does not require sub-level development within the stope, reducing stope cycle times and costs. The Company reviewed and visited the Hemlo Mine near Marathon, Ontario and determined MBRM as amenable for the Project. Members of Rubicon’s management and site teams have prior experience with MBRM at mining operations in Ontario and Manitoba. See Diagram 4 on page 16 of this news release for a conceptual diagram of the MBRM method. The conceptual LOM plan estimates total potential gold production of 493,583 oz, of which 44,047 ounces of potential production are anticipated during Pre-CP period. Please see Diagram 5 on page 16 of this news release for the conceptual LOM potential production profile. 12 Waste material form external dilution not at zero grade

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Mill Processing, Tailings Management Facility, and Water Treatment The Project has a fully-built and operational mill processing facility at site. The main components of the Project mill are a semi-autogenous grinding unit, Knelson gravity concentrators, a ball mill, and the carbon-in-leach circuit. The Project mill has an estimated top-end capacity of 1,800 tpd at the current configuration with minor upgrades. Further capital upgrades could allow the mill to process up to an estimated 2,500 tpd. During the 2018 bulk sample processing program, the Project mill achieved 1,540 tpd (based on 22-hour mill availability) and gold recoveries of 95.0% (43.0% from gravity). The New PEA contemplates a 20-month period to potential Commercial Production (the start of Year 1 in the conceptual LOM financial model; See Table 9 on page 12 of this news release), which is defined as 75% of the 1,250 tpd average permitted mill capacity over a period of 60 consecutive days, or approximately 937 tpd. In the conceptual LOM plan, processing from stockpiles is forecast to commence in the 8th month of Pre-CP (in Year -2). The New PEA assumes that Rubicon would apply to amend its permits to a higher throughput rate of 1,800 tpd during the Pre-CP period. After the receipt of the permit amendments, the Company would gradually increase throughput to a peak rate of 1,800 tpd, after sufficient stope development has been completed. The mill processing recovery is estimated to be 95% (43% from gravity). The Project currently has a fully-operational tailings management facility (“TMF”) and a water treatment plant in place. The New PEA contemplates minor upgrades to the TMF and water treatment plant, including the addition of a more efficient treatment of ammonia. These costs are all captured in the Initial Capital estimate. Capital and Operating Cost Estimates Please see Table 3 for a summary of the New PEA capital and operating cost estimates. Capital Cost Total conceptual LOM capital expenditures is estimated to be C$255.2 million. The New PEA has defined capital costs for estimation purposes as follows:

• Initial Capital (Pre-CP) - C$101.2 million: These are estimated capital expenditures up to conceptual Commercial Productions, including a 15% contingency. During Pre-CP, the Company plans to generate net cash flow of approximately C$28.8 million from early potential production, which translates to a Net Pre-CP Capital of C$72.4 million; and

• Sustaining Capital (CP) - C$154.0 million, or C$30 million per year of CP: Estimated capital expenditures

incurred from the declaration of conceptual Commercial Production to the end of the LOM, inclusive of closure costs.

The majority of the estimated capital costs (Initial and Sustaining Capital) are comprised of expected underground development (lateral, ramp, and vertical) below the 305-m Level and connecting the ramp from the 244-m Level to surface. Including indirect costs, the New PEA estimates that the average cost per underground development metre ranges between C$5,500 to C$6,500. This rate is based on actual development costs incurred by the Company during its 2018 test trial mining program, and at the higher-end of the range of peer estimates. The equipment fleet assumes equipment lease financing. Table 8 below provides the breakdown of the capital cost estimates:

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Table 8: Capital cost breakdown – Conceptual LOM (base case estimates)

Capital item: Pre-CP (millions)

Sustaining (millions)

Underground development and infrastructure C$43.2 C$86.7 Equipment C$16.9 C$53.1

Surface and mill (including TMF, water treatment, crushers, camp upgrades, buildings, etc.) C$22.8 C$6.5

Closure costs - C$7.7 Contingency (15%) C$18.4 -

Total Initial Capital C$101.2 - Total Sustaining Capital - C$154.0

Total conceptual LOM capital C$255.2 Capitalized Pre-CP operating costs C$45.7 -

Proceeds from sale of Pre-CP oz C$74.5 - Net Pre-CP operating cash flow C$28.8 -

Net Pre-CP Capital C$72.4 - Projected Funding Requirement8 C$80.9 -

Numbers may not add due to rounding

Operating Cost The operating cost estimates were derived from the Company’s 2018 test trial mining and bulk sample processing program, allowing the Company to collect actual operating cost information. The largest component of operating cost is labour (50-60%). The majority of the operating costs is anticipated to be in CAD. Please see Table 3 for a summary of the operating cost estimates and Table 7 for the estimated cost per tonne of each conceptual mining method contemplated. Royalties and Other Production Taxes and Tax Loss Pools The Project minerals claims that comprise the F2 Gold Deposit are subject to:

• 2.0% NSR payable to Franco-Nevada Corporation • 1.0% NSR payable to Royal Gold Inc.

Other production taxes include estimated LOM community payments. The Company currently has approximately C$690 million of tax-deductible pools, tax losses, and tax credits (“tax loss pools”) available for deduction at the potential commencement of Commercial Production. Application of these tax loss pools is estimated to result in the payment of no income taxes against the conceptual LOM net income from the Project. In the conceptual LOM plan, Rubicon will utilize approximately C$169 million of federal tax loss pools. The New PEA estimates that the application of tax loss pools improves conceptual LOM free cash flow by approximately C$95.5 million. It is estimated that Rubicon would have C$521 million of unused federal tax loss pools at the end of the conceptual LOM. Economics, Cash Flow Model and Valuation Sensitivities The New PEA demonstrates robust economic potential as summarized in Table 1. The Company believes that the 40.2% after-tax IRR estimated for the Project is a product of, among other things, significant sunk capital, application of tax loss pools, new and fully-operational infrastructure and equipment in place and a shortened timeline to cash flow from operations. Rubicon has a strong and successful management team with extensive operating experience in underground mining and improving operations, which will be a key factor in the Company’s effort to realize the Project’s estimated economic potential. In addition, considering that the majority of expenditures for the Project are expected to be in CAD, the depreciated CAD versus USD further enhances the estimated Project economics. Please refer to Table 9 on page 12 of

Page 8: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 8 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

this news release for the conceptual cash flow model for the Project. The Company believes that the Project’s estimated NPV provides compelling value for current and potential investors of the Company. Furthermore, the Company owns the second largest land package (more than 28,000 hectares) with regional exploration potential in the prestigious Red Lake Gold Camp, in one of the safest mining jurisdictions worldwide. Sensitivities of the estimated Project IRR and NPV are provided for gold price and USD/CAD exchange rate ratio estimates in Table 10 below. Other such sensitivities under different scenarios for grade, throughput, capital and operating costs are provided in Table 11 on pages 12 and 13 of this news release. Table 10: New PEA after-tax IRR and NPV estimated sensitivities to gold price and USD/CAD exchange rate ratio After-Tax IRR (%)/After-tax NPV5% (C$ millions)

USD/CAD exchange ratio

Gold Price (US$/oz)

$1,100 $1,200 $1,325 (base case) $1,400 $1,500

0.83 (4.4%)/($30.1) 9.3% / $14.9 24.4% / $71.1 32.8% / $104.8 43.5% / $149.7 0.81 (0.4%) /($17.8) 13.1% / $28.4 28.2% / $86.0 36.6% / $120.5 47.4% / $166.5 0.79 4.6% / ($1.3) 18.0% / $46.4 33.1% / $105.8 41.6% / $141.5 52.6% / $189.0 0.77 8.2% / $11.1 21.5% / $59.9 36.6% / $120.7 45.3% / $157.2 57.4% / $205.8

0.7519 (base case) 11.7% / $23.5 25.0% / $73.4 40.2% / $135.2 48.9% / $172.9 60.2% / $222.6 0.73 16.3% / $40.0 29.5% / $91.3 44.8% / $155.4 53.7% / $193.8 65.2% / $245.1 0.71 20.6% / $56.5 33.9% / $109.3 49.4% / $175.2 58.4% / $214.8 70.1% / $267.5

Permitting, Consultation, Closure and Rehabilitation Costs The Company will qualify for the material permits required for an average production rate of 1,250 tpd upon the successful implementation of an ammonia treatment upgrade to the Project water treatment system. At a future juncture, Rubicon will evaluate the permit amendments required for the increased projected production rate. The Company believes the increased production rate envisaged in the New PEA will not materially increase the surface area of the site, which could simplify the permit amendments and associated consultation process. Rehabilitation measures have been designed using a precautionary approach targeting the long-term physical and environmental stability of the site in accordance with applicable legislation and the associated First Nations’ consultation process. The rehabilitation measures are intended to return the site to a productive land use that will not require long-term care and maintenance. The conceptual end of LOM rehabilitation cost is estimated to be C$7.7 million, equivalent to the estimated salvage value of material site assets at closure. Salvage values were not included in the New PEA. The Company is continuing consultations with the First Nations communities, and local municipalities. Rubicon currently has Exploration Agreements in place with the First Nations communities in the region. Measures to Enhance the Accuracy of Estimates and Mitigate Risk The Company believes that the combination of data collected from the 2018 test trial mining and bulk sample processing program, sunk capital in the Project, and deep operating experience from underground operations amongst the management team, contribute towards the mitigation of risks and the accuracy of the estimates in the New PEA.

• Mill operation and recoveries: The Project mill processed more than 100,000 tonnes of material (both waste and mineralized material) between 2015 and 2018. During the 2018 bulk sample processing program, the Company achieved 95.1% recovery (43.2% from gravity) from the processing of more than 35,000 tonnes of mineralized

Page 9: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 9 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

material. The Project mill construction was completed in mid-2015 with a sunk cost of over C$150 million.

• Validated mineral resource estimate: Rubicon achieved positive reconciliation results from its bulk sample processing program in 2018, achieving grades, tonnes, and ounces that were 6.1%, 7.2%, and 13.8% higher, respectively, compared to the mineral resource block model estimate for the stopes mined (see November 29, 2018 news release for more details on the 2018 bulk sample processing program). The Company believes these results validate the geological model and the current mineral resource estimate.

• Mining method: The Company successfully tested both the Sub-Level Longhole and Uppers mining methods at the Project during its 2018 test trial mining program, achieving external dilution of 8.7% and demonstrating the amenability of the bulk mining to the deposit.

• Actual underground development and processing costs: Underground development comprises the biggest portion of capital and operating costs of underground operations. The Company has collected actual underground development costs, productivity rates, and other important information from its 2018 test trial mining program and from a 14,000 m of historical underground development.

• Additional sunk capital: In addition to the Project mill, critical items that have been mostly constructed include the TMF, a water treatment plant, earth and civil works, electrical substation, head frame and hoisting facility, and more than 14,000 m of well-maintained, underground development including a fully-operational shaft.

• Extensive underground mining experience: Management has underground operating and construction experience in challenging mines around the world, including the Witwatersrand basin in South Africa, in Northern Ontario (Sudbury, Timmins, Kirkland Lake, and Red Lake mining camps), Northern Manitoba, Val d’Or mining camp in Quebec, Northern New Brunswick, Northern Saskatchewan, and in Newfoundland. This collective experience will help to mitigate risks associated with future mine building and mine operations.

The Company understands that bringing development-stage projects to commercial production has numerous risks. Potential Opportunities to Optimize the New PEA Rubicon has identified the following opportunities to enhance the New PEA:

• Evaluate infill and step-out drilling of Explore Target areas11 (below the 854-m level). • Evaluate McFinley, and close proximity targets to potentially increase mineral resource estimates. • Evaluate the expanded usage of MBRM. • Electric and/or battery operated underground mobile equipment (e.g. haul trucks). • Evaluate the mining cut-off grade with a higher gold price assumption, which could potentially include more

stopes into the conceptual LOM plan. • Evaluate ore-sorting technology to potentially improve mill head grade.

Strategy Going Forward Rubicon plans to release an updated mineral resource estimate incorporating drilling results from 2019 in Q4/2019 with the goal of further increasing the Measured and Indicated mineral resource estimate above the current estimate of 589,000 contained ounces11, 13.

Page 10: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 10 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Within the Phoenix Gold Property claim boundary, the Company has identified exploration targets within 2 km from the Phoenix Gold Project shaft and surface infrastructure, which the Company intends to explore in 2020. Rubicon believes these targets have strong mineral potential based on historical mining and exploration. Company plans to file an updated Technical Report for the Project reflecting the New PEA on www.sedar.com within 45 days of this news release. Conference Call The Company’s senior management team will host a conference call today, Monday, August 19, 2019 at 8:30 am ET (5:30 am PT) to review and discuss the New PEA. Participants in Canada and the United States may join the conference call by dialing toll free +1 (888) 231-8191. For calls outside Canada and the United States, please dial +1 (647) 427-7450. For the webcast, please visit: https://event.on24.com/wcc/r/2068968/3DE1AE3E7A47611A6257EE81EB0E1B59 Supplementary presentation materials from the conference call and materials presented during an upcoming site visit will be uploaded on the Rubicon website www.rubiconminerals.com in the “Presentations” section. Qualified Persons and Quality Assurance and Quality Control (QA/QC) The content of this news release has been read, verified and approved by Michael Willett, P.Eng., Director of Projects, and Isaac Oduro, P.Geo., Manager of Technical Services for Rubicon, and Andrew Mackenzie, P.Eng. and Tim Maunula, P.Geo. for TMAC. All are Qualified Persons as defined by NI 43-101. Underground drilling was conducted by Boart Longyear Drilling of Haileybury, Ontario and was supervised by the Rubicon exploration team. All assays reported are uncut unless otherwise stated. All samples reported herein were performed by SGS Mineral Services of Red Lake, Ontario. All NQ core assays reported were obtained by fire assay with AA-finish or using gravimetric finish for values over 10.0 g/t Au. Intercepts cited do not necessarily represent true widths, unless otherwise noted, however drilling is generally intersecting interpreted mineralized zones at angles between -30o and +30o. True width determinations are estimated at 65-80% of the core length intervals for the 305 m Level drilling, and estimated at 75-95% of the core length for the 610 and 685 m Level drilling. Rubicon's quality control checks include insertion of blanks, standards and duplicates to ensure laboratory accuracy and precision. About Rubicon Minerals Corporation Rubicon Minerals Corporation is an advanced gold exploration company that owns the Phoenix Gold Project, located in the prolific Red Lake gold district in northwestern Ontario, Canada. Additionally, Rubicon controls the second largest land package in Red Lake consisting of over 285 square kilometres of prime, strategic exploration ground, and more than 900 square kilometres of mineral property interests in the emerging Long Canyon gold district that straddles the Nevada-Utah border in the United States. Rubicon’s shares are listed on the Toronto Stock Exchange (RMX) and the OTCQX markets (RBYCF). For more information, please visit our website at www.rubiconminerals.com. RUBICON MINERALS CORPORATION George Ogilvie, P.Eng. President, CEO, and Director

Page 11: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 11 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Table 4: 2019 MRE at 3.0 g/t Au Cut-Off Grade1 - Effective March 18, 201913

Mineral Resource Category Quantity (000’tonnes)

Grade (g/t Au)

Contained Gold Ounces

Measured (M) 442 6.99 99,000 Indicated (I) 2,485 6.13 490,000

M + I 2,927 6.26 589,000 Inferred 2,570 6.53 540,000

• Effective date for this Mineral Resource Estimate March 18, 2019 • Mineral Resource Estimate uses a break-even economic cut-off grade of 3.0 g/t Au based on assumptions of a gold price

of US$1,400 per ounce, an exchange rate of US$/C$0.77, mining cash costs of C$97/t, processing costs of C$24/t, G&A of C$6/t, sustaining capital C$20/t, refining, transport and royalty costs of C$57/oz, & average gold recoverability of 95%

• Mineral Resource Estimate reported from within an envelope accounting for mineral continuity • All figures are rounded to reflect the relative accuracy of the estimates and totals may not add correctly

Table 6: New PEA Conceptual LOM development schedule

Levels (m) Conceptual LOM Lateral and Ramp Development (m)

Total Pre-CP CP -2 -1 1 2 3 4 5

Surface 400 - - - - - - 400 122 512 - - - - - - 512 183 187 - - - - - - 187 244 42 - - - - - - 42 305 - - - - - - - - 366 747 603 - - - - - 1,350 427 46 1,639 462 - - - - 2,147 488 - 523 924 - - - - 1,447 549 - 570 1,451 173 - - - 2,194 610 183 395 756 518 - - - 1,852 640 - - - - - - - - 671 - 374 - 1,310 - - - 1,684 685 - 95 - - - - - 95 732 - 310 - - - - - 310 793 - 290 100 20 616 - - 1,026 854 - - 435 - 1,087 - - 1,522 915 - - 486 - 186 306 - 978 976 - - 209 1,493 - - - 1,702

1,037 - - - 505 203 - - 708 1,098 - - - 453 950 - - 1,403 1,159 - - - 266 833 1 - 1,100 1,220 - - - - 448 1,174 - 1,622 1,281 - - - - 448 649 395 1,492 1,342 - - - - 252 196 - 448 1,403 - - - - - 448 696 1,144 1,464 - - - - - 289 639 928 Totals 2,117 4,799 4,823 4,738 5,023 3,281 1,827 26,608

Numbers may not add up due to rounding *Year -2 (stub year) includes only 8 months of construction.

13For further details, please review the Rubicon news release dated March 29, 2019 and Technical Report filed on www.sedar.com on April 25, 2019. There is no certainty that the Measured and Indicated mineral resource estimates will be converted to the Proven and Probable mineral reserve categories and there is no certainty that these mineral resource estimates will be realized. There is no guarantee that Inferred mineral resource estimates can be converted to Indicated or Measured mineral resources, or that Indicated or Measured mineral resources will be converted to mineral reserves. Mineral resource estimates that are not Mineral reserves do not have demonstrated economic viability. The estimate of Mineral resources in this Table 4 may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant risks, uncertainties and other factors, as more particularly described in the Cautionary Statements at the end of this news release.

Page 12: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 12 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Table 9: New PEA Conceptual LOM cash flow model1 Pre-CP = Years -2#, -1 CP = Years 1 to 6#

#Year -2 (stub year) includes only 8 months of construction. Year 6 (stub year) includes only 1 month of operation. Table 11: Other sensitivity tables – New PEA Conceptual LOM

a) Diluted Head Grade (g/t Au) vs. Average Daily Mill Throughput (tpd) Estimated After-tax IRR (%)/After-tax NPV5% (C$ millions)

LOM Avg. Throughput

(tpd)

LOM diluted head grade (g/t Au)

4.50 4.75 5.00 5.31 (base case) 5.50 5.75 6.00

1,200 (5.9%)/($34.6) 2.8%/($7.4) 10.9%/$20.4 20.0%/$54.0 25.3%/$74.7 32.0%/$101.3 38.6%/$128.8 1,300 6.9%/$6.6 15.2%/$36.0 23.0%/$65.6 32.3%/$102.4 37.6%/$124.5 44.4%/$153.4 51.2%/$182.9

1,370 (bc) 14.9%/$34.8 23.0%/$65.4 30.9%/$96.9 40.2%/$135.2 45.7%/$158.8 53.0%/$190.6 59.9%/$221.4 1,500 28.7%/$87.8 37.0%/$121.9 45.1%/$156.4 54.6%/$197.5 60.5%/$223.7 68.1%/$257.9 75.5%/$291.9 1,600 38.5%/$128.2 47.1%/$165.0 55.3%/$200.5 65.6%/$246.7 71.5%/$273.6 79.4%/$309.7 87.2%/$346.4 1,700 48.2%/$169.8 57.0%/$208.1 65.6%/$246.9 75.8%/$293.4 82.3%/$323.5 90.5%/$361.7 98.7%/$397.9 1,800 57.5%/$210.4 66.4%/$250.6 75.6%/$292.5 86.5%/$342.9 93.0%/$373.2 101.4%/$408.3 109.8%/$438.8

Conceptual LOM Summary Unit YEAR -2 -1 1 2 3 4 5 6 7

Macro AssumptionsGold Price US$ / oz 1,325 1,325 1,325 1,325 1,325 1,325 1,325 1,325 - CAD/USD 0.7519 0.7519 0.7519 0.7519 0.7519 0.7519 0.7519 0.7519 0.7519 -

Mill FeedThroughput Tpd 1,370 133 670 1,225 1,516 1,691 1,699 1,577 823 - Mineralized Tonnage Tonnes 3,045,196 4,000 241,333 440,942 545,907 608,731 611,763 567,823 24,697 - Diluted Grade g/t 5.31 4.06 5.91 5.67 4.91 4.71 5.17 5.87 7.38 - Mill Recovery % 95.0% 95% 95% 95% 95% 95% 95% 95% 95% 0%

Conceptual Payable GoldGravity oz 223,411 224 19,713 34,568 37,025 39,587 43,683 46,093 2,518 - CIL oz 270,172 271 23,839 41,803 44,775 47,873 52,826 55,740 3,045 - Total Conceptual Payable Gold oz 493,583 496 43,551 76,371 81,800 87,460 96,510 101,833 5,563 -

Estimated Post-Tax Cash FlowNet Revenue C$ 000 868,442 872 76,627 134,371 143,923 153,882 169,806 179,172 9,788 -

Royalties and other production taxes C$ 000 (29,907) (78) (2,924) (4,656) (4,943) (5,241) (5,719) (6,000) (346) - Net Revenue Less Royalty C$ 000 838,534 794 73,703 129,715 138,981 148,641 164,087 173,171 9,442 -

Mining costs C$ 000 (268,404) (4,075) (25,388) (41,326) (45,975) (49,313) (49,903) (49,773) (2,651) - Milling costs C$ 000 (99,584) (411) (11,264) (15,390) (17,479) (18,505) (18,161) (17,398) (976) - Site G&A C$ 000 (23,824) (1,642) (2,898) (3,476) (3,779) (3,961) (3,970) (3,843) (255) - Mining Tax C$ 000 - - - - - - - - - - Total Operating Cost (391,812) (6,128) (39,550) (60,193) (67,233) (71,778) (72,033) (71,014) (3,882) -

Operating Cash Flow C$ 000 446,723 (5,334) 34,153 69,523 71,747 76,863 92,053 102,158 5,561 - Mine Development & U/G Infrastructure C$ 000 (129,956) (14,227) (28,993) (21,590) (22,177) (21,776) (15,533) (5,660) - - Equipment C$ 000 (69,917) (6,710) (10,140) (11,241) (10,227) (11,569) (10,118) (8,930) (982) - Surface & Mill Infrastructure C$ 000 (29,309) (20,639) (2,145) (2,525) (1,500) (2,500) - - - - Income tax C$ 000 - - - - - - - - - - Closure Costs C$ 000 (7,700) - - - - - - - (7,250) (450) Contingency (15%) C$ 000 (18,351) (7,036) (11,315) - - - - - - - Total Capital Costs (255,233) (48,611) (52,594) (35,355) (33,904) (35,845) (25,651) (14,590) (8,232) (450)

Estimated Cash Flow Before Financing Activit C$ 000 191,489 (53,946) (18,441) 34,167 37,843 41,017 66,402 87,567 (2,671) (450) Change in Working Capital C$ 000 -$ (693) 2,135 2,232 (84) 262 1,295 908 (5,724) (330)

Post Tax Cash Flow C$ 000 191,489 (54,639) (16,306) 36,399 37,759 41,279 67,697 88,475 (8,395) (780) Post Tax NPV Unlevered Cash Flows 5% $135,233Post Tax IRR 40.2%

Unit Cost Metrics - Pre-CP excluded from calculationOperating Cost (LOM) C$ / tonne $128.67 - - 137 123 118 118 125 157 - Operating Cash Cost (C1, CP) US$ / ounce $623.93 - - 638 663 662 606 569 571 - AISC* US$ / ounce $881.55 - - 987 975 970 806 676 1,684 - AIC* US$ / ounce $1,031.21 - - 1,183 1,158 1,141 961 823 4,375 - * Exempt of Corporate Costs

Page 13: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 13 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

b) Total Operating Cost (C$/tonne) vs. LOM Capital Cost Change (%) – Conceptual LOM Estimated After-tax IRR (%)/After-tax NPV5% (C$ millions)

LOM Capital Cost Change (%) Total Operating Cost (C$/tonne)

$110.00 $128.67 (base case) $150.00

-25% 80.9%/$234.9 65.6%/$189.4 48.7%/$137.3 -15.0% 67.6%/$213.2 54.0%/$167.7 38.8%/$ 115.6

$255.2M (base case) 51.6%/$180.1 40.2%/$135.2 27.0%/$83.8 + 15.0% 39.6%/$148.2 29.2%/$102.7 17.1%/$50.6

+25% 32.8%/$126.4 23.0%/$80.9 11.6%/$28.8 Diagram 1: 2019 MRE block model – long section10,11,13

Page 14: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 14 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Diagram 2: Diagram of New PEA Conceptual LOM development – Looking north

Page 15: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 15 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Diagram 3: Conceptual diagram of Sub-Level Longhole and Uppers mining methods (Diagram not to scale)

Page 16: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 16 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Diagram 4: MBRM long section schematic – Courtesy of ManRocDevelopments Inc. (Diagram not to scale)

Diagram 5: Conceptual LOM potential production* profile1

*Year -2 (stub year) includes only 8 months of construction. Year 6 (stub year) includes only 1 month of operation.

oz g/t Au tpd US$/oz

Estimated Annual Production vs. Mill Head Grade Estimated Mill Throughput vs. Cost Per Ounce (Cash cost/AISC)

4.06

5.91

5.67 4.91 4.715.17 5.87

7.38

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

0

20,000

40,000

60,000

80,000

100,000

120,000

-2 -1 1 2 3 4 5 6

Projected production Mill head grade

Pre-CP CP

$638 $663 $662

$606 $569 $571

$987 $975 $970$806

$676

$1,684

$0

$200

$400

$600

$800

$1,000

$1,200

$1,400

$1,600

$1,800

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

-2 -1 1 2 3 4 5 6

Mill throughput Cash Cost per oz AISC

Pre-CP CP

Page 17: Rubicon Minerals Delivers New PEA Demonstrating a 40.2% After … · 2019-08-19 · Rubicon President and CEO George Ogilvie, P.Eng., stated, “The New PEA presents a significant

Page 17 of 18

PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Cautionary Statements regarding Forward-Looking Statements and Mineral Resource Estimates All statements, other than statements of historical fact, contained or incorporated by reference in news release, including but not limited to any information as to the future performance of the Company, constitute “forward-looking statements” and “forward looking information” (collectively, “forward-looking statements”) within the meaning of applicable Canadian and United States securities legislation. Generally, these forward-looking statements can be identified by the use of forward-looking terminology such as “amenability”, “anticipates”, “assumption”, “base case”, “believe”, “compelling”, “conceptual”, “consideration”, “contemplate”, “contingency”, “conversion”, “demonstrate”, “drive”, “envision”, “estimates”, “evaluate”, “expected”, “exploration”, “factors”, “focus”, “forecast”, “forward”, “future”, “intend”, “IRR”, “inventory”, “LOM”, “margin of error”, “may”, “measures”, “mitigation”, “model”, “NPV”, “opportunity”, “optimize”, “path”, “PEA”, “plan”, “potential”, “preliminary”, “profile”, “project”, “projected”, “prospective”, “risk”, “sensitivity”, “slated”, “strategy”, “target”, “upgrade”, “valuation”, “viability” and “will”, or variations of such words, and similar such words, expressions or statements that certain actions, events or results can, could, may, should, will (or not) be achieved or occur in the future. In some cases, forward-looking information may be stated in the present tense, such as in respect of current matters that may be continuing, or that may have a future impact or effect. Forward-looking statements include, but are not limited to, statements regarding mineral resource estimates, mine plans and life, the anticipated timing of the delivery and details of the updated Technical Report and/or updated mineral resource estimate for the Project, the results of the New PEA (including any anticipated economics, such as return on capital (including IRR) and NPV, free cash flow, gold production (payable or otherwise), capital and operating costs, LOM, estimated tonnes and grade, construction period and other results of the New PEA, all of which are estimates only), impact of infrastructure on the economics of the New PEA, impact of results from the 2018 test trial mining and bulk sampling on the New PEA, the anticipated outcome of further oriented infill and expansion drilling of the Project, the potential tonnage of mineralized material and its grade from the Project, the impact of the data from the 2019 drilling program, the potential to improve the quantities and classification of mineral resource estimates, the potential impact of drilling on stope dimensions, future mining, Project economics and the understanding of the structural geology including at depth, and any potential to move the Project back into production. See also Footnote 1 of this news release. Forward-looking statements are made as of the date of this news release, based on the expectations, assumptions, opinions and estimates of management as of the date such statements are made, which management considers reasonable, and represent management’s best judgment. If such expectations, assumptions, opinions and estimates prove to be incorrect, actual and future results may be materially different than expressed or implied in the forward-looking statements. Forward-looking statements are subject to a number of known and unknown risks, uncertainties and other factors which may cause Rubicon’s actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include, among others: possible variations in mineralization, grade or recovery or throughput rates; uncertainty of mineral resource estimates; inability to realize exploration potential, mineral grades and mineral recovery estimates; actual results of current exploration activities; actual results of reclamation activities; uncertainty of future operations, delays in completion of exploration plans for any reason including insufficient capital, delays in permitting, and labour issues; conclusions of future economic or geological evaluations; changes in project parameters as plans continue to be refined; failure of equipment or processes to operate as anticipated; accidents and other risks of the mining industry; delays and other risks related to operations; timing, receipt and maintenance of permits and other required regulatory approvals; the ability of Rubicon and other relevant parties to satisfy regulatory requirements; the ability of Rubicon to comply with its obligations under material agreements including financing agreements; the availability of financing for proposed programs and working capital requirements on reasonable terms; the ability of third-party service providers to deliver services on reasonable terms and in a timely manner; risks associated with the ability to retain key executives and key operating personnel; cost of environmental expenditures and potential environmental liabilities; dissatisfaction or disputes with local communities or First Nations or Aboriginal Communities; failure of plant, equipment or processes to operate as anticipated; market conditions and general business, economic, competitive, political and social conditions; our ability to generate sufficient cash flow from operations or obtain adequate financing to fund our capital expenditures and working capital needs and meet our other obligations; the volatility of our stock price; the ability of our common stock to remain listed and traded on the TSX; and the “Risk Factors” in the Company’s annual information form dated March 22, 2019 (“2019 AIF”). The foregoing list of assumptions, risks, uncertainties and other factors is not exhaustive. The foregoing list of assumptions, risks, uncertainties and other factors is not exhaustive. The forward-looking statements contained or incorporated by reference herein are expressly qualified by this cautionary statement as well as those in other continuous disclosure documents of the Company filed under its profile at www.sedar.com including, but not limited to, the 2019 AIF. Forward-looking statements contained herein are made as of the date of this news release and Rubicon disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or results or otherwise, except as required by applicable securities laws. Cautionary Note to U.S. Readers Regarding Estimates of Measured, Indicated and Inferred Mineral Resources This news release uses the terms “Measured” and “Indicated” mineral resources and “Inferred” mineral resources. The Company advises U.S. investors that while these terms are recognized and required by the Canadian Securities Administrators, they are not recognized by the United States Securities and Exchange Commission (SEC). The estimation of “Measured” and “Indicated” mineral resources involves greater uncertainty as to their existence and economic feasibility than the estimation of Proven and Probable Reserves. The estimation of “Inferred” mineral resources involves far greater uncertainty as to their existence and economic viability than the estimation of other categories of mineral resources. It cannot be assumed that all or any part of a “Inferred”, “Measured”, or “Indicated” mineral resource estimate will ever be upgraded to a higher category.

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PR19-13 For more information, contact Allan Candelario, CFA, Director, Investor Relations and Corporate Development

Phone: +1 (416) 766-2804 | E-mail: [email protected] | www.rubiconminerals.com Rubicon Minerals Corporation | Suite 830–121 King St. W. | Toronto ON, CANADA M5H 3T9

The Toronto Stock Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release

Under Canadian rules, estimates of Inferred mineral resources” may not form the basis of feasibility studies, pre-feasibility studies or other economic studies, except in prescribed cases, such as in a preliminary economic assessment (or PEA) under certain circumstances. The SEC normally only permits issuers to report mineralization that does not constitute “Reserves” as in-place tonnage and grade without reference to unit measures. Under U.S. standards, mineralization may not be classified as a “Reserve” unless the determination has been made that the mineralization could be economically and legally produced or extracted at the time the Reserve determination is made. U.S. investors are cautioned not to assume that any part or all of a “Inferred”, “Measured” or “Indicated” mineral resource exists or is economically or legally mineable. Information concerning descriptions of mineralization and mineral resources contained herein may not be comparable to information made public by U.S. companies subject to the reporting and disclosure requirements of the SEC.