Xanadu Mines has received the full report on new results from preliminary metallurgical test work at the Altan Tolgoi deposit within the Kharmagtai Copper-Gold Project, in the South Gobi region of Mongolia. The tests on diamond core from high-grade tourmaline breccia mineralisation returned positive results.
The metallurgical test work was aimed at producing a float concentrate of copper, gold and silver. The test work was combined with an optical mineralogy study and grinding power requirement testing.
Xanadu commissioned Mining Associates to undertake the test work program to assess the response to flotation and provide initial data on grinding energy requirements. A single 30kg composite of the coarse reject samples for flotation testing and half core sample were selected for Bond Ball Mill Work Index (BBMWi) determination. The assay head grade of the master composite was 4.37% copper, 1.86 g/t gold and 14.1 g/t silver, which compared reasonably well with the expected grades from the average of the interval assays.
The sample produced from the material provided responded very well to simple flotation testing with low collector dosage.
- Copper recoveries into a rougher concentrate ranging between 93.6 to 95.3% copper;
- Gold recoveries into the rougher concentrate ranging between 93.4 to 95.4% gold;
- Silver recoveries into the rougher concentrate ranging between 86.7 to 89.9% silver;
- Exceptional recoveries from simple flotation testing using low collector addition;
- Simple ore mineralogy with vast majority of copper as chalcopyrite; and
- Indicative grinding power requirements (Bwi 18.9 kWh/t) average for this rock type.
Xanadu’s executive director and CEO Dr Andrew Stewart said, “The early stage flotation test results on the high-grade tourmaline breccia mineralisation are exceptional. The above average results, achieved at a moderate grind size, indicate high recoveries, and that a standard crushing, grinding and flotation process is all that will be required to extract all the economic minerals from the tourmaline breccia mineralisation.
"As expected, gold recoveries were also very high. While further testing is required across the ore body as the project advances, we foresee no significant hurdles to producing a high quality concentrate via standard processing pathways from the tourmaline breccia mineralisation at Altan Tolgoi.
"These positive metallurgical test results provide more confidence with the drilling under way to expand the resource by targeting mineralisation in the tourmaline breccia. The new results also complement the previous metallurgical studies undertaken on the shallow copper-gold stockwork zones of the ore body.”