Metallurgy issues resolved at Boumadine with 96.37% gold recovery

Posted by Daniel Gleeson on 9th August 2018

Maya Gold & Silver has received the results of the latest metallurgical tests on fresh rock from Boumadine in Morocco. The most recent metallurgical test done at the SGS Laboratory in Lakefield, Ontario on a Boumadine fresh rock sample, and the best so far, provided the following results:

Calculated head grade:  0.43% Pb, 1.40% Zn, 4.46 g/t Au and 455 g/t Ag.

  • Zn recovery :  79.5%
  • Zn concentrate :  54.2%
  • Au recovery :  96.37% (including the gold recovered in the zinc concentrate)
  • Ag recovery :  50.44% (including the silver recovered in the zinc concentrate)

The testing process included grinding of the sample to approximately 80% passing 75 μm, followed by differential flotation of the galena, sphalerite and other sulphides, followed by pressure oxidation of the lead and sulphides concentrates and eventually followed by cyanide leaching of the oxidized material.

Samples were taken at Boumadine in the ore pile (100kg +) adjacent to the main shaft of the central zone. The pails were shipped from Morocco to GoldMinds Geoservices in Quebec Canada office, which sent them to SGS Lakefield after physical inspection.

The successful process involves: crushing, grinding followed by flotation to remove lead from the zinc concentrate, afterward produces a Zinc and sulphide concentrate. The lead concentrate was added to the sulphide concentrate and run into pressure-oxidation system, which afterward went into cyanide leaching for gold and silver extraction.

These results are significantly much better than the first process metallurgical testing using roasting of sulphides. The previous tests by the Chinese were lower in gold recovery and the roasting was encapsulating the silver providing poor recovery at the cyanidation

Maya is still waiting for the latest tests on the tailings from SGS Lakefield and these will be disclosed once received, compiled, validated and analysed.

“I am very pleased with the results showing a high recovery as compared to historical ones. Over various testing we have been able to unlock the gold from the sulphides with a known commercial and environmentally friendlier process,” said Gilbert Rousseau Eng. Independent Metallurgist of GoldMinds.