Overview
Stage | Pre-Feasibility |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Drift & Fill
- Transverse stoping
- Longitudinal retreat
- Cemented backfill
|
Processing |
- Solvent Extraction
- Calcining
- Counter current decantation (CCD)
- Acid tank leaching
|
Mine Life | 6.5 years (as of Jan 1, 2019) |
The UG PFS is based on using underground mining methods, and processing of 1,000 tonnes per day (tpd) via acid leaching, solvent extraction (SX), and precipitation. The Project has the potential to produce up to 15 million pounds (Mlb) of triuranium octoxide (U3O8) per year in the form of yellowcake. The UG PFS presents an alternative scenario to the combined open pit and underground plan presented in April 2019 (the Hybrid PFS). |
Latest News | Fission Announces the Closing of a US$10 million Credit Facility with Sprott April 7, 2020 |
Source:
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Deposit Type
- Vein / narrow vein
- Metamorphic hosted
Summary:
The Triple R deposit is considered to be an example of a basement hosted vein-type or fracture-filled uranium deposit.
Mineralization is known to occur at five locations on the PLS Property, from west to east: 1) R1515W, 2) R840W, 3) R00E, 4) R780E, and 5) R1620E, the most significant of which is the R780E zone. Uranium mineralization discovered on the Property to date is hosted primarily in basement lithologies with subordinate amounts intersected in the overlying Devonian sedimentary rocks. Mineralized zones occur within or near to the MSZ over a 3.17 km strike length along the PLG-3B EM conductor.
Uranium mineralization at the PLS Property is hosted primarily within metamorphosed basement lithologies and, to a much lesser extent, within overlying Meadow Lake Formation sedimentary rocks.
Mineralization within the Meadow Lake Formation sedimentary rocks typically occurs as fine grained disseminations, sooty blebs, and rarely semi-massive uranium mineralization. Uranium concentrations within the Meadow Lake Formation are generally low to moderate, however, grades greater than 1.00 wt% U3O8 have been intersected. When mineralized, the Meadow Lake Formation is typically strongly clay and chlorite altered, though locally can be pervasively hematite stained a deep red. Relative to basement hosted mineralization, only a very small amount of mineralized Meadow Lake Formation has been intersected on the PLS Property to date.
Basement hosted mineralization at the PLS Property occurs in a wide variety of styles, the most common of which appears to be fine grained disseminated and fracture filling uranium minerals strongly associated with hydrocarbon/carbonaceous matter within the MSZ. Uranium minerals, where visible, appear to be concordant with the regional foliation and dominant structural trends identified through oriented core and fence drilling (i.e., steeply dipping to the southeast). Typically, mineralization within the MSZ is associated with pervasive, strong, greygreen chlorite and clay alteration. The dominant clay species identified through PIMA analysis are kaolinite and magnesium-chlorite interpreted to be sudoite. The pervasive clay and chlorite alteration eliminates the primary mineralogy of the host rock with only a weakly defined remnant texture remaining. Locally, intense rusty limonite-hematite alteration in the orthogneisses strongly correlates with high grade uranium mineralization and a “rotten”, wormy texture.
Less common styles of uranium mineralization within the MSZ, which are often associated with very high grade uranium, include: semi-massive and hydrocarbon rich; intensely clay altered (kaolinite) with uranium-hydrocarbon buttons; and massive metallic mineralization. These zones of very high grade mineralization generally occur along the contact of the MSZ and intensely silicified QFBG-GN and comprise a high grade mineralized spine. This spine may represent a zone of intense structural disruption which has been completely overprinted by alteration and mineralization.
Uranium mineralization within the north and south QFBG-GN which bound the MSZ generally occurs as fine grained disseminations and is almost always associated with pervasive whitishgreen clay and chlorite alteration with local pervasive hematite. The mineralized zones within the QFBG-GN are interpreted to be stacked structures parallel to the MSZ strike and dip along the PLG-3B conductor.
Results of the detailed mineralogical work at the PLS Property indicate that the dominant uranium mineral present is uraninite, with subordinate amounts of coffinite, possible brannerite and U-Pb oxide/oxyhydroxide. Uranium minerals occur mainly as anhedral grains and polycrystalline aggregates with irregular terminations; irregularly developed veinlets, locally showing extremely complex intergrowths with silicates; micrometric inclusions and dendritic intergrowths with silicates; and very fine-grained dissemination intercalated with clays. In the samples studied, uranium minerals also occur as fine-grained inclusions in carbonaceous matter (hydrocarbon).
R00E ZONE
PLS12-022 intersected a total of 12.5 m of uranium mineralization beginning at the top of bedrock (55.3 m) including a main zone averaging 1.1% U3O8 over 8.5 m from 70.5 m to 79.0 m.
At R00E, uranium mineralization is generally found within several metres of the top of bedrock which occurs at a depth of 50 m to 60 m vertically from surface. Uranium mineralization at R00E is hosted within the MSZ, northern QFBG-GN, and Meadow Lake Formation sediments. No uranium mineralization has been intersected to date in the silicified hanging wall or in the southern QFBG-GN.
R780E ZONE
Similar to R00E, R780E mineralization trends approximately northeast, in line with the MSZ.
As with the R00E zone, R780E uranium mineralization has varying thickness, from tens of centimetres along the flanks to very wide intervals within the MSZ, as seen in PLS14-248 which intersected a lens of high-grade uranium mineralization over 15 m in true thickness. In section view, R780E mineralization generally occurs as sub-vertically and southeast dipping zones, concordant with the regional dip. A very high-grade spine of uranium mineralization occurs within the main zone and has been traced as a series of lenses across almost the entire strike length of the R780E zone. The high-grade spine occurs adjacent to the contact between the MSZ and silicified QFBG-GN.
At the western R780E zone, uranium mineralization extends to near the top of bedrock. Moving eastward, the top of mineralization appears to be plunging at approximately -7° to the east. In general, the western R780E mineralization morphology is similar to the R00E, spatially restricted to the northern QFBG-GN, MSZ, and Meadow Lake Formation sediments. Moving eastward through the R780E zone, mineralization has been intersected within the MSZ, northern QFBG-GN, and Meadow Lake Formation sediments and, unlike the R00E zone, strong mineralization has been cored in the silicified QFBG-GN and southern QFBG-GN.
R1620E ZONE
Uranium mineralization at the R1620E occurs in what is interpreted to be the eastern extension of the MSZ and appears to be associated with the MSZ – silicified QFBG-GN contact.
R840W ZONE
Similar to the R00E and R780E zones, mineralization trends northeasterly in line with the MSZ.
R1515W ZONE
Uranium mineralization at the R1515W occurs in the MSZ and appears to be associated with the MSZ – silicified QFBG-GN contact.
Mining Methods
- Drift & Fill
- Transverse stoping
- Longitudinal retreat
- Cemented backfill
Summary:
The mining method for the underground will be longhole retreat mining in both transverse and longitudinal methods, and some localized drift and fill mining based on current block model information. The mining will progress from the bottom levels to the top, and from the southwest to northeast. Mining is planned at nominally 1,000 tpd ore.
The mine will be accessed using a decline originating to the west of the R00E deposit. The decline will include a box cut into the overburden, and a portal face collared in the overburden. The first stage of the decline will be developed through overburden for approximately 405 m, using the New Austrian Tunneling Method (NATM – a method commonly used in soft ground), also known as Sequential Excavation Method (SEM), or Sprayed Concrete Liner (SCL). Following this, the decline will transition through weak bedrock for an additional 133 m, until reaching the competent bedrock.
A key component of the underground design is the concept of using artificial ground freezing to extract some of the crown pillar – the mineralized material that approaches the overburden layer. This will be done using horizontal directional drilling from the shore of Patterson Lake and then pumping a refrigerated brine solution through the drill holes to effectively freeze the ground in the areas of stopes.
The portal is situated within the Box Cut. The face of the portal is perpendicular to the gradient of the decline, while the sidewalls “fade away” from the face slope to the slope of the Box Cut. The portal face and sidewalls require extensive ground support to ensure stability throughout the LOM. A series of soil nails, spilings, mesh, and shotcrete is all planned to ensure the stability of the portal face in advance of excavation. The ground support will be installed in 1.5 m vertical lifts. Drainage is planned so that precipitation is directed away from the slopes of the Box Cut and portal.
The area around the decline will be dewatered prior to excavation. The decline will be developed on an east-west alignment at a gradient of -15%. The first component of the decline is through overburden, followed by development through transition bedrock, and development through competent bedrock. To develop through overburden, a tunneling method known as the NATM will be utilized.
VENTILATION SHAFTS
Both shafts will traverse through overburden into bedrock. To excavate through the overburden, a ground freezing program is required, to a depth of 75 m for both the fresh air and exhaust shafts. Both shafts will be lined with 300 mm high- strength concrete.
BGC assumes mined-out stopes will be backfilled with a cemented rock fill (CRF) and uncemented rock fill (URF) combination.
Ground support is designed for primary (waste) and secondary (production cross-cut) headings stability. As a protective measure against radioactive radiations, shotcrete will be used in all secondary drifts. The assumed excavation dimensions are:
- Primary headings (Waste drifts (in footwall)): 5 m x 5 m
- Intersections: 6.5 m effective span
It has been assumed for efficiency that intersection ground support types will be the same type, but not necessarily the same length, as the primary heading ground support, with the addition of cable bolts as required to provide long support to any wedges.
The deposit extends under Patterson Lake, and approaches the contact between watersaturated overburden and bedrock. Consequently, careful consideration must be placed in evaluating the feasibility of extracting this mineralization. A key consideration of the underground only PFS was to minimize the disturbance to Patterson Lake, and therefore the peninsula option was eliminated. Ground freezing using horizontal directional drilling emerged as the preferred option due to the following:
- Ground freezing has been used extensively in the Athabasca Basin to isolate uranium deposits from poor ground conditions
- Ground freezing could be installed remotely, prior to any development occurring in the area of the crown pillar
- Freeze plant infrastructure can be placed on surface, adjacent to the collars of the freeze holes
RADIATION PROTECTION
When considering the design of the mine, radiological protection of site personnel is paramount. In the context of uranium mining, radiation exposure comes from gamma rays, alpha particles, beta particles, radon gas, and the decay of radon gas into what is known as radon progeny. The primary concern from a radiation protection point of view relates to exposure from gamma radiation and radon progeny. Gamma radiation affects both underground and open pit mining, while radon progeny is generally only a concern in underground mining. The Canadian Safety Nuclear Commission (CNSC) sets out rigorous standards for the amount of radiation exposure that a worker can receive over a set time interval (typically a five year window). It is then up to the company to establish yearly, quarterly, monthly, weekly, and daily radiation exposure limits that a worker is permitted to receive.
The four tenets used to minimize radiation exposure are time, distance, shielding, and ventilation.
- Time: minimize the time that a worker needs to spend in an area of radioactivity
- Distance: maximize the distance that a worker needs to be in relation to a radioactive area
- Shielding: maximize the shielding that protects a worker from the source of radioactivity
- Ventilation: plan an effective ventilation system that consistently removes air-borne contaminants such as radon progeny and gas
In the underground mine plan, the tenets of time, distance, shielding, and ventilation have all been considered. The ventilation system is planned in a way that utilizes “single-pass ventilation”, where fresh air brought through raises is used only once in an ore-heading before it is discharged to the exhaust system. Ventilation from waste headings may be re-used provided that it meets accepted standards for air quality. Shielding will be incorporated into both the mine mobile equipment, and ground support practices used at the mine. Furthermore, the mine design has been carried out to minimize the time – and maximize the distance – a worker is in the vicinity of radiation bearing mineralization.
STOPE AND DEVELOPMENT DESIGN
Underground mining will be carried out using transverse and longitudinal longhole retreat mining. Transverse mining makes up the majority of the mining on the west and middle areas of the orebody. Longitudinal mining is done in the east end of the orebody where there are multiple narrow lenses.
Underground stopes are planned on 20 m sub-levels. Stope lengths are 15 m in strike and have variable widths.
The development mining cycle in ore includes the following items:
- Development drilling.
- Blasting.
- Mucking.
- Mechanical scaling.
- Shotcrete – used for immediate support and shielding.
- Bolting and screening.
The production mining cycle includes the following items:
- Cable bolting – Action takes place as soon as a drift is completed. Item is done for the entire stoping area.
- Production Drilling/Blasting – Action takes place after cable bolting. Item is done for the entire stoping area.
- Mucking.
- Backfill, and cure time.
Mucking of the adjacent stope does not take place until backfilling is completed.
Processing
- Solvent Extraction
- Calcining
- Counter current decantation (CCD)
- Acid tank leaching
Flow Sheet:
Summary:
The process flowsheet selected for the Project is based on unit processes commonly used effectively in uranium process plants in northern Saskatchewan, while utilizing some new innovations in some of these unit process designs to optimize plant performance.
While the Triple R deposit contains gold values that may be recoverable, a high-level economic analysis by RPA has shown this to have limited impact on overall project profitability at current market conditions and gold recovery was thus excluded from this design. Should market forces change in the future it could, however, be reasonably easily engineered into the existing design and constructed without harming throughput or recovery from the uranium process plant.
The conceptual mill design will have a nominal feed rate of 350,000 tpa, operate 350 days per year, and be able to produce nominally 15.0 Mlb per year of U3O8. The mill design will have an estimated recovery ranging from 95% to 97% and is designed in ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
U3O8
|
Recovery Rate, %
| ......  |
U3O8
|
Head Grade, %
| 1.61 |
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Reserves at September 19, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
2,299 kt
|
U3O8
|
1.61 %
|
81.4 M lbs
|
Indicated
|
2,216 kt
|
U3O8
|
2.1 %
|
102.4 M lbs
|
Indicated
|
2,216 kt
|
Gold
|
0.61 g/t
|
43.1 koz
|
Inferred
|
1,221 kt
|
U3O8
|
1.22 %
|
32.8 M lbs
|
Inferred
|
1,221 kt
|
Gold
|
0.5 g/t
|
19.6 koz
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
.......................
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.......................
|
|
Nov 29, 2019
|
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Corporate Filings & Presentations:
Document | Year |
...................................
|
2019
|
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News:
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