CuFe (ASX:CUF) reports results from a first-pass metallurgical test on its Orlando deposit, located in the Tennant Creek Copper/Gold Project has shown ‘promising’ results for copper recovery, with its primary objective to test the flotation response of the copper oxide ore.
The company commissioned Independent Metallurgical Operations to undertake a program of ‘sighter’ bench scale metallurgical test work on both oxide and transitional composites of historical diamond drill core from Orlando.
The primary objective of the work being to achieve a positive result with respect to the floatation of oxidised copper mineralisation through conventional oxide flotation, and to inform a more comprehensive metallurgical program.
Two tests were performed on the copper oxide composite, with the first test (FT01) designed to establish some basic operating parameters such that the second test (FT02) could provide a more realistic assessment of what might be achievable for oxide floatation.
Results of FT02 showed the copper oxide responded exceptionally well producing copper recovery to rougher concentrate of 79.8% Cu, and rougher concentrate grade of 34.4% Cu.
This is an ‘outstanding’ result for copper oxide rougher stage floatation, highlighting that high saleable copper grades can be readily achieved.
The single test performed on the transitional sample (higher sulphur content) responded well to a copper sulphide-copper oxide, differential flotation flowsheet, with both copper sulphide and copper oxide minerals responding well.
The test produced a copper recovery to concentrate at 90.6%, and rougher concentrate grade of 11.2% Cu, which is to be expected of a high sulphur ore, with upside expected via subsequent regrinding and a floatation cleaner stage to achieve a more saleable concentrate grade of over 20% Cu.
The results of the oxide floatation test demonstrate that a standard floatation circuit design could be utilised for oxide, transitional and primary copper mineralised ore sources, which would have positive implications for both the capital and operating costs of the processing plant.
The results of the oxide floatation test demonstrate that a standard floatation circuit design could be utilised for oxide, transitional and primary copper mineralised ore sources
Indicatively high gold recoveries to concentrate for both oxide and transitional composites, with the nuggety gold effect highlighting the need for additional test work to more accurately quantify gold recovery.
The drilling program (reverse circulation and diamond drilling) completed in August provides an additional core for the purpose of progressing a more comprehensive testwork program, which will be guided by the results of this preliminary ‘sighter’ testwork.
CuFe Executive Director Mark Hancock said these first-pass results are very pleasing.
“Given the primary objective of this initial work was to test the potential to float a concentrate from the copper oxides, these first pass results are very pleasing.
Not only do the testwork results point to the potential to utilise standard floatation for the Orlando copper oxides but the grade of rougher concentrate in this initial test, at 34.3%, was also very encouraging.
There is a strong consensus view amongst commodity forecasters that there will be significant increases in copper supply required to meet the demand growth that will come from global electrification.
A project like Orlando, where the ore is planned to be accessed via a cut back to an existing open pit, is one of the simpler projects that can be part of this supply response.
For this reason the Company will continue to focus on the work streams that are most relevant to the project’s successful development.
Further metallurgical test work on the core we have just acquired through our recently completed drilling at Orlando will be a key part of that.”
CuFe submitted to Independent Metallurgical Operations and its subsidiary laboratory Metallurgy a total of 34kg of selected copper oxide intervals, comprising 9 individual samples of cut diamond drill core, all taken from 3 historic drillhole cores recovered from the Tennant Creek Orlando core farm.
The 2 master composites were stage crushed, separately and in entirety to P100 less than 3.35mm.
This was followed by splitting of the 2 master composites as required to provide the following:
- Head sample analysis via elemental assaying and speciation analysis
- Head sample mineralogical characterisation via QXRD and optical/SEM analysis, focusing on mineral associations and valuable mineral liberation sizes (work in progress)
- Flotation test work
Separate copper oxide and copper transition flotation test work has been performed as follows:
- Grind flotation test charges to target P80 75µm in Perth tap water, then transferred to a floatation cell with more water added
- Copper oxide composite, single-stage rougher floatation tests, which generated rougher kinetic concentrates and final copper concentrate of saleable grade
- Copper Transition composite- single stage rougher flotation tests, which generated rougher kinetic concentrates (further regrinding and cleaner flotation stage required to achieve final copper concentrate of saleable grade)
- Floatation test product samples dewatered using a fine filter press and oven dried at 70ºC
- Depending on weight, samples are either pulverised or homogenised, split and pulverised.
- Samples dispatched for assay analysis
CuFe is an emerging copper and iron ore company. Its strategy is focused on near-term, ‘high grade premium product’ iron ore projects and maintaining exposure to strategic metals.
The company has interests in various projects and tenements prospective for iron ore, copper and gold all located in Australia, and owns a 60% interest in the Tennant Creek Copper-Gold Project
Images: CuFe Limited & iStock
