Initial metallurgical test work on the Pegmont Lead-Zinc project has been completed on the Burke Hinge Zone open pit target (BHZ) and the high zinc grade Zone 5 underground target.
Using industry standard test work the initial flotation tests produced separate lead and zinc concentrates using bench scale batch (open cycle) flotation. Tests were performed by ALS Metallurgy, in Burnie Tasmania, under the supervision of Vendetta’s consulting metallurgist Mr. Geoff Richmond.
Three composites from sulphide mineralization at BHZ, and Zone 5 Lens B and C were processed. A fourth test was performed on transition mineralization at BHZ. In all cases, separate marketable lead and zinc concentrates were produced.
Table 1. Composite Details, Overall Recoveries and Concentrate Grades.
|Area Composite||Bore Holes Included in Composite||Composite Head Grades (diluted)||Lead Circuit||Zinc Circuit|
|Pb %||Zn%||Pb Recovery %||Concentrate Pb Grade %||Zn Recovery %||Concentrate Zn Grade %|
|BHZ||PVRD023, 024, 026, 027, 041, 042, 043, 044 & 045||5.02||3.03||91.5||70.6||61.8||50.7|
|Zone 5, Lens B||PVRD013, 030, 032, 33, 34 & 37||5.61||4.74||88.5||68.0||75.6||50.1|
|Zone 5, Lens C||PVRD030, 033 & 037||4.30||5.48||83.0||66.1||76.7||50.3|
* Transition mineralization is defined as predominately sulphide lead-zinc mineralization in variably weathered rocks, with high iron oxide mineralogy.
- BHZ and Zone 5 composites were selected such that they are representative of the lead-zinc mineralization intersected during Vendetta’s 2016 drilling program.
- Sulphide composites were prepared using quarter core HQ. BHZ transition sample was prepared using half core HQ.
- All sulphide composites included barren hanging wall and footwall country rock to simulate mining dilution. The BHZ transition test did not include dilution.
- Pre-concentration method investigated included magnetic separation and heavy media separation. These were performed on the BHZ sulphide and Zone 5 Lens B composites, results indicate that no meaningful advantage can be gained from pre-concentration.
- All composites were ground to P80 passing 105 μm.
- Each composite was subject to a series of developmental batch flotation tests, including a roughing only test and either two or three cleaning tests with rougher concentrate regrind (P80 passing 15 to 27 μm)
- BHZ Transition test was performed on an intersection from one drill hole only and is not considered representative. Zinc recoveries in the zinc concentrate of the BHZ Transition were hampered by locking of sphalerite in galena and gangue minerals, this is reflected in the relatively high recovery of zinc (22.3%) to the lead concentrate. While transition mineralization represents a relatively small proportion of the mineralization at the BHZ open pit target flotation optimization work is ongoing.
- Bond Ball Mill Work Index comminution test work, was performed on the BHZ Sulphide and Zone 5 Lens B composites, returning 16.6 kWh/t and 19.4 kWh/t respectively, placing them in the medium to medium hard range.
- There remains scope to further optimize the flotation results. It is generally accepted that locked cycle flotation will result in higher recoveries more comparable to commercially operated flotation plant, compared to batch flotation.
- Further details about these tests will be made available on the Companies web page and Corporate Presentation. About Vendetta Mining Corp.
Peter Voulgaris, MAusIMM, MAIG, a Director of Vendetta, is a non-independent qualified person as defined by NI 43-101. Mr. Voulgaris has reviewed the technical content herein, and consents to the information provided in the form and context in which it appears.
Geoff Richmond FAusIMM, a Consulting Metallurgist to Vendetta, is a qualified person as defined by NI 43-101. Mr Richmond has reviewed the metallurgical technical content herein, and consents to the information provided in the form and context in which it appears.