Blind Creek Resources announces metallurgical results for Blende Zinc-Lead-Silver Deposit
VANCOUVER, April 18, 2018 /CNW/ - Blind Creek Resources Ltd. (TSX-V: BCK) – ("Blind Creek" or the "Company") reports the Company has received a metallurgical testing report from BV Minerals - Metallurgical Division for the Company's potentially open pit Blende Zinc-Lead-Silver Project, situated 64 kilometres northeast of Keno Hill, Yukon, Canada.
In November, 2017 Mr. Frank Wright, P.Eng., commenced a preliminary four month staged metallurgical test program entailing characterization and optimization studies for comminution, dense media separation (DMS), flotation, liquid/solid (LS) separation and concentrate characterization on 175 kilograms of mineralized split drill core samples obtained from the Blende Deposit, which had been stored on site for several years. Despite an elevated extent of sulphide oxidation the test results showed a good response using conventional mineral processing procedures. Head grades ranged from 1.5% to 5.4% for lead, 1.5% to 3.5% for zinc, along with 17 to 65 g/t for silver. Based on the ratio of sulphide to total sulphur analysis the extent of oxidation ranged from 32% to 92%. Studies concluded the Blende Deposit has an average oxide content of 21% which allows for recovery of both sulfides and oxides at the recoveries used in the recently released Blende National Instrument (NI) 43-101 Mineral Resource Estimate. (News Release April 11, 2018)
As a means of pre-concentration prior to milling, Blende metallurgical samples were subjected to DMS at a pre-screened particle size from ¼" (6.3 mm) to 1" (25 mm). The samples responded favorably with the grades of the concentrate close to double that of the DMS feed grades. When including screened fines, the metal recovery ranged from 85% to 90% for lead; and 82% to 86% for zinc, while rejecting approximately half the feed mass.
Differential flotation performed on the drill core samples also provided an encouraging initial response without the need for fine grinding. While further optimization is required, a satisfactory response was evident at a relatively moderate grind of a particle size distribution 80% passing 110 microns. Locked cycle and continuous testing flotation was not performed for this initial portion of testing on the Blende samples. The estimated flotation recoveries are from the open cycle tests, which include cleaner tailing that are recycled in a locked cycle or continuous circuit. For zinc, this recovery was more challenged than lead, likely due to oxidation resulting in a portion of the zinc reporting to the lead concentrate, despite use of depressant and pH control. For the samples tested this resulted in an average estimated ~70% zinc recovery to the zinc float concentrate. Lead float recoveries for this test program were approximately 85%, at a corresponding concentrate grade of ~60% lead. Most of the silver, as would be desired for maximum smelter payments, report to the lead concentrate, with a total silver recovery of 90%, at a grade of up to 823 g/t silver into the lead concentrate, depending on the head assay.
Mr. Wright, P.Eng. states "With further evaluation the process response can be expected to improve on these results with ongoing project advancement. In part this would be due to evaluating more representative mineralized samples taken at depth that are shown to have a lower extent of sulphide oxidation. In turn that should improve process performance as compared to these more highly oxidized samples that had been stored on surface. Regardless, metallurgical test results to date provide an encouraging indication that the Blende mineralogy will respond well to standard process techniques."
Blende NI 43-101 Resource Highlights
Indicated Resource – Contained Metal
159 Million lbs. Zinc
157 Million lbs. Lead
4.19 Million oz. Silver
Inferred Resource – Contained Metal
1.461 Billion lbs. Zinc
1.364 Billion lbs. Lead
33.98 Million oz. Silver
The Blende Project is a potential bulk tonnage, open pit approach that offers some distinct cost advantages to other advanced lead-zinc projects in Canada, which are typically underground. Blende Resource mineralization outcrops at surface, is confined to 2 pit shapes approximately 2 kilometres apart (view map) and remains open in areas northwest, southeast and below the "reasonable prospects of economic extraction" open pit shapes within the 8 kilometre-long mineralized corridor, including the outer Far West, Far East and Shanghai discoveries. A drill program to extend the mineralization along strike and down-dip will start in 2018 (fully permitted) to test these potential open pit extensions.
The Base Case Mineral Resource is reported in Table 1.
Table 1. Base Case Mineral Resource (at NSR cutoff grade of $CDN39.35 (ZnEq=2%))
Category | Cutoff | In situ | In situ Grades | In situ Metal Content | |||||||
ZincEq | Zinc | Lead | Silver | NSR | OXRAT | Zinc | Lead | Silver | |||
Indicated | 2.0 | 3,650 | 5.18 | 1.98 | 1.95 | 35.7 | 101.87 | 0.08 | 159 | 157 | 4,192 |
Inferred | 2.0 | 32,980 | 5.03 | 2.01 | 1.88 | 32.0 | 98.91 | 0.22 | 1,461 | 1,364 | 33,980 |
Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that mineral resources will be converted into mineral reserves.
The Blende Mineral Resource Estimate was prepared by Moose Mountain Technical Services (MMTS), an independent mining consulting company.
The Zinc Equivalent (ZnEq) and Net Smelter Return (NSR) metal price assumptions of: $US1.20/lb zinc, $US1.00/lb lead, and $US19.00/oz silver and an exchange rate of US$0.80 = $1CDN. Metal recovery assumptions are: 70% zinc, 85% lead and 90% silver (10% to zinc concentrate and 80% to lead concentrate). Payables based on comparable smelter terms and a 3% Royalty are; 85% zinc, 95% lead and 80% silver.
ZnEQ = Zn% + (Pb% * 1.0 * 0.85 * 0.95)/(1.2 * 0.70 * 0.85) + (Aggpt/31.1034 * 19 * 0.90 * 0.80)/(1.2 * 0.70 * 0.85 * 22.0462)
Mining costs used for the "reasonable prospects of economic extraction" pit shapes are CDN$1.88/tonne for all material within the potential open pits. Processing, G&A, Surface Services and Tailings costs used have a total of CDN $37.50/tonne material milled. Costs are based on comparable Zn-Pb-Ag projects in North America. The exchange rate is US$0.80 = CDN $1. Open pit slopes are 45 degrees.
Geologic domains are modelled based on faulting, lithology and grade distribution. Four domains have been modelled, with assays composted to 3m intervals honoring domain boundaries and capped by domain based on cumulative probability plots. Zinc, lead and silver grades have been interpolated using Ordinary Kriging (OK).
Indicated Resources must contain at least two drill holes within 30m of the block. Inferred Resources have at least 2 drill holes within 120% of the Variogram Range, with extrapolation of the data limited.
Density values are based on a correlation of (Zn+Pb) grades and re-assayed intervals from a sampling program undertaken in the summer of 2017.
A supporting 43-101 Technical Report will be filed on SEDAR (www.sedar.com) and on the Blind Creek website (www.blindcreekresources.com) no later than May 25th, 2018.
Qualified Persons
Ms. Sue Bird, P.Eng., Principal at MMTS is independent of Blind Creek Ltd. and a 'Qualified Person' (Q.P.) as defined under Canadian National Instrument NI 43-101. Ms. Bird is responsible for the Mineral Resource Estimate and directly related information in this news release. Mr. Frank Wright, P.Eng., of F. Wright Consulting Inc. and a Qualified Person (Q.P.) as defined by National Instrument 43-101 is responsible for the Metallurgical Studies and directly related information in this news release. Mr. Bob Morris, P.Geo, Principal Geologist of MMTS and a Qualified Person (Q.P.) as defined by National Instrument 43-101, is responsible for all other technical information (information not directly related to the Mineral Resource Estimate and Metallurgical studies) in this news release. Technical aspects of this news release have been reviewed and approved by Ms. Bird, Mr. Wright and Mr. Morris.
About Blind Creek Resources Ltd.
Blind Creek is a Vancouver-based junior resource company focused on lead-zinc-silver project acquisition, exploration and development. The Company's flagship property is the Blende Deposit in north-central Yukon, the largest carbonate-hosted zinc-lead-silver deposit in Yukon Territory (M. Robinson and C.I. Godwin, Economic Geology (1995).
More recently the Company has signed an agreement to acquire a 100% interest in the AB Property, a mid-stage Mississippi Valley (MV-Type) Zinc-Lead exploration property in Northwest Territories and announced its intention to spin out its 100%-owned, Historic and fully-permitted Engineer Gold Mine Property, situated 32 km southwest of Atlin, B.C.
For additional information please visit the company website www.blindcreekresources.com.
On behalf of the Board of Directors,
Mr. Brian P. Fowler, P.Geo.
President
bfowler@blindcreekresources.com
Nelson Da Silva – Manager Corporate Communications
(604) 722-0041
Neither 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.
This news release contains certain forward looking statements which involve known and unknown risks, delays, and uncertainties not under the control of Blind Creek Resources Ltd. which may cause actual results, performance or achievements of Blind Creek Resources Ltd. to be materially different from the results, performance or expectation implied by these forward looking statements. By their nature, forward looking statements involve risk and uncertainties because they relate to events and depend on factors that will or may occur in the future. Actual results may vary depending upon exploration activities, industry production, commodity demand and pricing, currency exchange rates, and, but not limited to, general economic factors. 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.
SOURCE Blind Creek Resources Ltd.
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