Vancouver, July 25, 2018 – John Cumming, President and Chief Executive Officer of Stellar AfricaGold Inc., (TSX-V: SPX) (“Stellar” or the “Company”) is pleased to announce:
Gravity Mill Efficiency Review Complete and Adjustments Underway
Stellar is pleased to announce that the review of processing operations at the Balandougou gravity mill is complete. Several processing inefficiencies were identified including the efficacy of the grinding within the ball mill, the configuration of the Knelson concentrators and the adjustment of the shaking table. Corrective measures to improve these production inefficiencies and increase the gold recovery are underway and the necessary changes and upgrades together with other minor adjustments to the plant equipment are expected to be completed by the end of August at which time processing of the 15,000 tons bulk sample of B3 Zone gold mineralization will resume.
Management Commentary
“Following the temporary cessation of processing activities in early July, an intensive review of processing operations including consultations with Stellar’s on-site technical team, other mining operators and mining equipment providers was undertaken” commented Stellar COO Maurice Giroux.
Mr. Giroux further explained “The free gold within the B3 oxide Zone ranges from ‘fine’ to ‘very fine’ and for maximum gold recovery it is essential that all of the individual components within the mill circuit operate at peak efficiency and at full capacity.
The gold within the B3 sheared zone gold is of two types; either it is free gold after the oxidization of the host material or has resisted oxidation and remains contained within the quartz veins. The Ball Mill, the last component within the primary and secondary crushing lines, is designed to pulverize incoming quartz from the secondary crusher down to smaller than 0.1millimeter. However, a notable amount of the input quartz was only being crushed to between 0.5 and 1.0 centimeter in size which had to be screened out of the circuit because they were too large to be pumped into the Knelson Concentrators. An offsite grinding test on 2 tons of those oversized quartz pieces revealed that the rejected quartz contained approximately 1.25g/t Au, a significant amount of unrecovered gold. The Company is now adapting a closed circuit which will return the oversized quartz to the Ball Mill for reprocessing.
Following constructive discussions with several other experts in gravity gold recovery, the Company is also altering the configuration of their two Knelson Concentrators. The Concentrators will be reinstalled in series rather than parallel as they previously. Stellar is also seeking a Falcon Concentrator to add it as a third concentrator in the concentration circuit. A Falcon Concentrator, which is exceptionally efficient at the recovery of very fine gold, i.e. smaller than 10 microns in size, would capture the very fine gold that was not captured by the two Knelsons. However, the search for a Falcon concentrator will not delay restarting processing operations at the mill.
Finally, the size of the slurry basin between the Ball Mill and the Knelsons will be doubled to increase overall processing capacity.”
To read the complete July 25, 2018 Balandougou update news release click here.
