The company decides to temporarily suspend mining operations at Relief Canyon (above) in order to prioritize capital for the Cosalá operations restart. (Photo: Americas Silver and Gold)

Following an extensive review and a challenging ramp-up at Relief Canyon in Pershing County, Nevada, Americas Gold and Silver proceeded with run-of-mine heap leaching and continued its efforts to resolve metallurgical challenges in the second quarter. On August 13, however, the company decided to temporarily suspend mining operations at Relief Canyon in order to prioritize capital for the Cosalá operations restart while it continues leaching operations and ongoing metallurgical test work.

President and CEO Darren Blasutti said the company continues to look at alternatives to improve the metallurgical recovery at Relief Canyon and believes “there remains significant value in the asset despite the initial challenges.”

The company met several important commissioning targets, including initial construction capital, and planned mining and crushing rates, but the ramp-up at Relief Canyon has been and continues to be challenging since the first poured gold in February 2020, according to the company. During this period, the company and its consultants performed extensive analyses and implemented a number of procedural changes to address the startup challenges typical of a heap leach operation. The company identified naturally occurring carbonaceous material within the Relief Canyon pit. The company did not identify this material in the feasibility study.

The company began two small run-of-mine test pads in the first quarter to evaluate the possibility of simplifying the flowsheet by bypassing the crushing and conveying circuits and transitioned to this method of ore placement in May. However, the operation has not seen a sustained material increase in recoveries to date. Additional improvements in the predictive ability of the resource model are progressing with incorporation of the latest geological detail from recent pit mapping as well as new data from an extensive re-assaying program of 13,000 historic exploration pulp samples for the presence of carbonaceous material. Completion of this data compilation and analysis is targeted for late in the third quarter. Management also initiated several metallurgical test work programs to investigate ore treatment options, including carbon-in-leach processing.

The company said it will continue leaching operations and working to improve recovery and operations through an extensive audit of drilling, sampling, ore control, and modelling, implementing internal QA/QC programs, and metallurgy testing program on carbonaceous material.