Mexus Gold US has announced that its ball mill gravity gold recovery system is now operational. This system will allow the company to run high grade material from the Julio quartz vein at its Santa Elena mine located in Caborca, Mexico.
In addition, the company announced an important discovery concerning gold recovery from its heap leach pad at the mine site. Mexus has been and continues to recover gold from the mineralised material placed on the heap leach pad. The resulting gold production from this work has been variable leading to an analysis of the heap leach pad.
It has been found that the salt placed on the pad by the prior operator continues to limit gold recovery. Assays of the cyanide solution returning to the pregnant pond are not representative of the material being placed on the pad. The company decided to remove the material from the top of the heap leach pad down to 2 m from the bottom and have it assayed. These assays showed that salt is causing issues with gold recovery.
The silver in this material, when coming into contact with salt, turns to silver chloride. Cyanide solution with gold reacts with silver chloride and turns the gold to a metallic state inhibiting recovery. The silver chloride found in the bottom 2 m was assayed and showed an extremely high level of gold value (oz to the t).
Mexus CEO, Paul Thompson, along with Chief Geologist, Cesar Lemas, determined that the bottom 2 m of the heap leach pad needs to be removed and run through the ball mill gravity system. Tests have shown that 95% of the gold in the silver chloride material can be recovered using the company’s gravity ball mill circuit. This work has already begun. These efforts accomplish two things for the company. First, this allows for gold recovery of highly assayed material at the bottom of the heap leach pad. Secondly, it fixes the heap leach pad allowing for normal and consistent recovery of gold going forward.
Mexus will continue to produce gold in 4Q20. The company was looking to give guidance for 4Q20 but determined that the recent findings have made it difficult to give an estimate.
Mexus CEO, Paul Thompson, commented: “I’m excited for gold production in the coming weeks. We believe that a substantial amount of gold trapped on the pad is now going to be recovered.”
Read the article online at: https://www.globalminingreview.com/handling-processing/07102020/mexus-gold-announces-ball-mill-operation-update/