VANCOUVER, Sept. 11, 2013 /CNW/ - Kivalliq Energy Corporation ("Kivalliq", TSX-V: KIV) today provided an update on ongoing metallurgical and beneficiation studies for Kivalliq's 340,268 acre Angilak Property in Nunavut Territory. This update summarizes preliminary results from work performed on the Lac 50 Trend deposits, including: metallurgical testing of the J4 and Lac 50 zones as well as characterization studies related to optimal ore sorting methods.
"Results from ongoing metallurgical work at Lac 50 are encouraging," stated Chuck Edwards, Director of Metallurgy at AMEC. "Optimizing sulphide recovery, plus improvements to alkaline leach kinetics using oxygen as oxidant, could have a positive impact on reducing costs associated with potential treatment options."
Key Point Summary:
- J4 Zone flotation achieved an optimum sulphide recovery of 99.2% in alkaline solution at a grind size of 100% passing 140 mesh (106 µm).
- Positive alkaline leach results on J4 Zone indicate rapid uranium extraction: 92.3% in 12 hours, 95.2% in 24 hours and 96.7% in 48 hours.
- Using improved alkaline leach parameters defined by the J4 Zone testing, retesting of the 2012 Lac 50 composite upgraded the leach extraction of uranium to: 91.7% in 12 hours, 95.1% in 24 hours and 96.4% in 48 hours. (previous results released February 28, 2013)
- J4 Zone sulphide flotation and alkaline leach results are consistent with other Lac 50 deposits.
- Preliminary ore sort characterization of rock specimens from Lac 50 deposits indicates that radiometric sorting will be very effective. Radiometric characterization analysis demonstrates a 56% reduction in mass with 98% U3O8 recovery.
Metallurgical Results Demonstrate High Uranium Recoveries and Rapid Leach Kinetics
In 2012, the Saskatchewan Research Council ("SRC") commenced a metallurgical testing program on core from Kivalliq's Lac 50 Trend. The program objectives were to maximize uranium extraction through the removal of sulphides using flotation and optimizing the alkaline leaching processes. Results from the 2012 metallurgical program were very encouraging with high U3O8 recovery rates and the production of a low impurity final yellowcake product. (see Kivalliq news release of February 28, 2013)
In 2013, metallurgical testing was expanded to include a composite sample from the newly discovered J4 deposit. The goal was to compare alkaline leach parameters of the J4 Zone to previous test work, while continuing to develop optimal grinding, sulphide flotation and leach conditions. A 26.0 kilogram composite derived from 44 split drill core pulp rejects was submitted to the SRC Mineral Processing Group for metallurgical analysis. Pulp samples used in the composite were selected from 17 holes drilled along 650 metres of strike length at J4 Zone. A head grade sample taken from the composite and analyzed by total digestion ICP at SRC is shown in Table 1.
Table 1 J4 Zone Composite Sample ICP Total Digestion Assay (ppm)
Sulphide flotation on J4 Zone composite material tested variable grind sizes in water and alkaline solution respectively. An optimum sulphide recovery of 99.2% was achieved in alkaline solution at a grind size of 100% passing 140 mesh (106 µm).
Alkaline leaching of J4 Zone flotation tails achieved rapid uranium extraction of 86.7% in 6 hours, 92.3% in 12 hours, 95.2% in 24 hours, 96.7% in 48 hours, 97.2% in 72 hours, and 97.5% in 96 hours under the following conditions: 100% passing 140 mesh grind, 70oC, 50% solids slurry, 50 g/L Na2CO3 and 20 g/L NaHCO3 solution chemistry and oxygen at 300 kilopascals as oxidant.
Using the same optimized conditions, an additional test was conducted on a sample from the 2012 Lac 50 composite (but at 100% passing 200 mesh grind as per 2012 composite preparation). When compared to the 2012 result leach kinetics improved with uranium extractions of 83.6% in 6 hours, 91.7% in 12 hours, 95.1% in 24 hours, 96.4% in 48 hours, 97.0% in 72 hours, and 97.3% in 96 hours. Figure 1 compares alkaline leach kinetics from 2013 to that of 2012.
Preliminary Ore Sorting Investigation Shows Amenability to Radiometric Sorting
In May 2013, Kivalliq engaged TOMRA Sorting Inc. (TOMRA) in Surrey, British Columbia to characterize a set of rock specimens from the Lac 50 Trend uranium deposits using Radiometric (RM), Dual Energy X-Ray Transmission (DEXRT), conductivity and magnetic susceptibility (EM) and visible spectrum (Optical) sensors. Preliminary ore characterization studies were performed to determine whether mineral sorting technology could efficiently identify and segregate uranium bearing minerals.
"We are very pleased with the success of preliminary radiometric sorting." stated Jeff Ward, President Kivalliq Energy. "Larger bulk testing using production-scale sorting methods will now be considered as a processing option to concentrate uranium bearing rocks at Lac 50."
Kivalliq delivered to TOMRA a 1.45 kilogram suite of high grade, medium grade, low grade and waste specimens, comprised of 138 sized rock chips (2.0 cm to 3.0 cm across), collected from half split NQ drill core intersections representative of the Lac 50 Trend uranium deposits. Characterization measurements were carried out on the entire suite using the RM, DEXRT, EM and Optical sensors. Following sensor characterization, individual rock specimens were shipped to SRC for analysis by total digestion ICP. The average grade of the sample was 1.06% U3O8.
Theoretical perfect sort recovery curves for the samples were obtained by ordering the individual rocks in descending U3O8 grade. Using the order of the perfect sort and the mass and grade of each specimen, curves were calculated for a theoretical perfect recovery, concentrate grade and tails grade for the samples. These results are then compared to the grade and recovery curves for each sensors tested.
Using radiometric sensors proved to be the most effective method for sorting Lac 50 samples by U3O8 grade. RM characterisation was performed at Hazen Research Inc. (Hazen) in Golden Colorado where a RM bench top test system was configured to simulate a full scale RM sorter. The theoretically perfect sort curve showed 98.3% recovery of U3O8 at a mass recovery of 44% (or 56% mass rejected with only 1.7% loss of U3O8). The actual short integration RM sort recovered 98.0% of U3O8 at a mass recovery to concentrate of 44% (56% mass rejected with 2.0% loss of total U3O8) and is almost identical to a theoretical perfect sort recovery curve. Concentrate and tails grades were 2.37% U3O8 and 0.03% U3O8 respectively. Figure 2 shows comparative RM sort curves for the Lac 50 sample.
The SRC facility operates in accordance with ISO/IEC 17025:2005 (CAN-P-4E), General Requirements for the Competence of Mineral Testing and Calibration laboratories and is accredited by the Standards Council of Canada. The samples are analyzed by SRC's ICP-OES multi-element ICP1 assay method. ICP1 results are reported in parts per million (ppm). 1 ppm = 1g/tonne, 10,000 ppm = 1%. TOMRA ICP U assays in ppm were converted to % U3O8 as follows: % U3O8 = ppm U x 0.01179
TOMRA (formerly Commodas Ultrasort and Terra Vision) are leaders in the specialized field of sensor-based sorting technology for the mining industry. Experience from 15 test facilities worldwide have led to significant advances in in automated material identification and sorting for the mining and mineral processing industries.
Hazen performs research and development for clients in the mineral, chemical, energy, and environmental fields. The company serves clients worldwide on projects ranging from bench-scale experiments to continuous pilot or demonstration plants.
Jeff Ward, P.Geo, President of Kivalliq and a Qualified Person for Kivalliq, has reviewed and approved the scientific and technical information contained in this release. For disclosure related to the inferred resource for the Lac 50 Trend uranium deposit, please refer to Kivalliq's news release of March 1, 2013.
About Kivalliq Energy Corporation
Kivalliq Energy Corporation (TSX-V: KIV) is a Vancouver-based uranium exploration company holding Canada's highest-grade uranium resource outside of Saskatchewan's Athabasca Basin. Its flagship project, the 340,268 acre Angilak Property in Nunavut Territory, hosts the Lac 50 Trend with a NI 43-101 Inferred Resource of 2,831,000 tonnes grading 0.69% U3O8, totaling 43.3 million pounds U3O8. Kivalliq's comprehensive exploration programs continue to advance the Lac 50 Trend and demonstrate the "District Scale" potential of the Angilak Property. Kivalliq's team of northern exploration specialists have forged strong relationships with sophisticated resource sector investors and project partner Nunavut Tunngavik Inc. ("NTI") in order to advance the Angilak Property. Kivalliq was the first company to sign a comprehensive agreement to explore for uranium on Inuit Owned Lands in Nunavut Territory, Canada and is committed to building shareholder value while adhering to high levels of environmental and safety standards and proactive local community engagement.
For Angilak Property data tables, maps and figures: www.kivalliqenergy.com/angliak/technical/images/
To view a short video related to the Angilak Property, Evolution of the Lac 50 Trend, click here: Evolution of the Lac 50 Trend
On behalf of the Board of Directors
James R. Paterson, CEO
Kivalliq Energy Corporation
Kivalliq Energy Corporation is a member of the Aurora Mineral Resource Group of companies, for more information please visit www.auroraresource.com.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Certain disclosures in this release, including the budget and exploration program proposed for the Angilak Property, constitute forward-looking statements that are subject to numerous risks, uncertainties and other factors relating to Kivalliq's operations as a mineral exploration company that may cause future results to differ materially from those expressed or implied in such forward-looking statements, including risks as to the completion of the plans and projects. Readers are cautioned not to place undue reliance on forward-looking statements. Other than as required by applicable securities legislation, Kivalliq expressly disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events, or otherwise.
Cautionary Note concerning estimates of Inferred Resources:
This news release uses the term "inferred resources". Inferred resources have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of an Inferred Mineral Resource will ever be upgraded to a higher category. Kivalliq advises U.S. investors that while this term is recognized and required by Canadian regulations, the U.S. Securities and Exchange Commission does not recognize it. U.S. investors are cautioned not to assume that part or all of an inferred resource exists, or is economically or legally mineable.
SOURCE: Kivalliq Energy Corporation
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