Separating Nickel And Copper Concentrates At Nickel Shaw Project

TORONTO, ON - Nickel Creek Platinum Corp. reported the final results of its Phase II metallurgical program on the Nickel Shaw Project located in the Yukon, Canada. The Phase II Metallurgical Program succeeded in its primary objective of separating bulk CuNi concentrate into separate sale test workable nickel and copper concentrates, representing the most in-depth and comprehensive metallurgical undertaking completed to date at the Project.

Diane Garrett, President and CEO said, "This is a huge milestone for the Project. When we produced a saleable bulk concentrate in 2017 as part of our Phase I metallurgical program we soon realized the economic benefits that could be achieved from separating the nickel and copper concentrates.  The Phase II program achieved good separation into saleable concentrates.  Producing two concentrates, nickel and copper, not only provides the Company with additional flexibility for selling its concentrates into the market but is also expected to yield enhanced payable terms based on recent discussions with smelters. During this Phase II program, the Company also embarked on optimizing the flow sheet, and in addition to the benefits of producing separate concentrates, the Company was able to increase grinding size, thereby lowering energy consumption as well as identifying potential opportunities for reducing capital costs and processing costs. The results of this comprehensive work will be used in the Preliminary Economic Assessment ("PEA") which is currently underway."

The Metallurgical Program has been conducted in partnership with XPS Expert Process Solutions ("XPS"), a Sudbury based technical consultancy firm that is conducting the metallurgical test work on behalf of Nickel Creek and has extensive experience in flowsheet development and nickel-copper separation. The Mini Pilot Plant ("MPP") utilized in the Phase II Metallurgical Program is the property of XPS and replicates, at a small scale, a commercial processing flowsheet.

The XPS MPP processed 1,100 kg of Run of Mine (ROM) ore with a head grade of 0.33% Ni, 0.15% Cu, 0.018% Co, 0.23 gpt Pt, 0.29 gpt Pd, and 0.04 gpt Au. The processing circuit incorporated conditioning with sulphuric acid @ pH 5.7 followed by rougher flotation and magnetic scavenging of the rougher tailings. The rougher and magnetic concentrates were individually reground and floated at neutral pH in a closed-circuit three-stage cleaner to yield a bulk CuNi concentrate. The MPP returned a bulk CuNi concentrate with grades of 6.1% Ni and 3.1% Cu (total 9.1% Ni+Cu) at recoveries of R% Ni = 53.3%, R% Cu = 59.6%, R% Co = 57.0%, R% Pt = 47.9%, R% Pd = 53.9% and R% Au = 74.4%.  The MgO level of the bulk CuNi concentrate was 5.6%.  

The MPP pilot run provided approximately 25kg of stable-state concentrate suitable for development and evaluation of Cu/Ni separation. The flowsheet for Cu/Ni separation employed high-pH (lime) and aerative conditioning in the presence of sodium metabisulfite and activated carbon followed by five stages of sequential cleaning. The final Cu/Ni separation flowsheet was assessed in locked cycle flotation testing and the Cu/Ni locked cycle test demonstrated substantial copper / nickel separability. An extended 10-cycle test showed good stability within three cycles, allowing reliable metal split factors to be collected over seven test cycles. The test produced a Cu concentrate assaying 13.8% Cu, which contained 52.2% of the Cu (bulk concentrate basis), with only 2.5% of the bulk concentrate Ni. The nickel concentrate assayed 6.5% Ni, 1.8% Cu, 0.36% Co and 8.3 g/t (Pt+Pd+Au) and contained 7.6% MgO. Metal recoveries to the Ni concentrate (on the bulk concentrate basis) were R% Ni = 97.5%, R% Cu = 46.8%, R% Co = 98.1%, R% Pt = 94.2%, R% Pd = 90.7%, R% Au = 68.6%. 

It is well recognized that the mechanics of pilot scale cleaner flotation equipment cannot perfectly duplicate the superior mechanics of zero-entrainment commercial scale cleaning cells, such that pilot demonstration results need to be modeled/scaled from locked cycle performance to commercial scale circuit prediction. Based upon the observed metal split factors from the locked cycle test, process scale up projected that the commercial copper split from bulk concentrate to copper concentrate is anticipated to reach 18.0% Cu with approximately 1.1% Ni grade containing 62% of the copper (bulk concentrate basis) with <2% of the bulk concentrate nickel. Under such conditions, the corresponding nickel concentrate will contain 6.7% Ni, 1.3% Cu, 0.36% Co, 8.4 g/t Pt+Pd+Au and approximately 6.1% MgO. The recovery (bulk concentrate basis) are estimated to be R% Ni = 98, R% Cu = 38%, R% Co = 98%, R% Pt = 98 %, R% Pd = 94%, R% Au = 68%. On a whole ore basis, 37.0% of the ROM copper units are expected to report to the copper concentrate, along with 1.0% of the nickel units. The corresponding nickel concentrate contains 52.3% of the ROM nickel, 22.6% of the copper, 56.0% of the cobalt, 46.9% of the platinum, 50.6% of the palladium, and 50.8% of the gold.  

The separate nickel and copper concentrate grades, while on the lower end of industry comparables, are within the current global range for marketability. The de-risking of the metallurgy meshes advantageously with the Project's proximity to infrastructure, favorable geopolitical location, and the growing global smelter demand for nickel-cobalt and copper sulphide concentrates.

Batch scale variability testing from samples across the Life of Mine of the deposit has indicated a high correlation between nickel recovery and ore total sulphide content. This new understanding of nickel recovery across the deposit, in conjunction with the results of the Phase II Metallurgical Program, will be incorporated into a new PEA to be released in the fall.