TSX-listed Monarch Gold has announced the results of a geochemical assessment done on ore from its Wasamac deposit, in Quebec, to determine the characteristics of its tailings.
Monarch reports that the results show that the Wasamac tailings are non-potentially acid generating (non-PAG), with "very little, to no" tendency to generate net acidity.
Moreover, they show that the tailings contain excess capacity to neutralise acid from external sources. This conclusion is founded on the abundance of calcium- and magnesium-carbonate minerals in the ore and tailings, which represent effective neutralisation potential to consume any acid produced by the oxidation of the sulphide mineral, pyrite, that will be present in the ore and tailings.
The results of the assessment will provide the basis for scoping appropriate candidate tailing storage facilities for Wasamac.
Monarch assigned Ecometrix to assess the tailings according to their geochemical characteristics, using the ore as a surrogate for the tailings and the potential implication of storage and weathering in a typical storage facility.
The investigation of the Wasamac tailings was based on the results of metallurgical testing that was done in 2018, and recent independent geochemical analysis of archived samples from the four Wasamac ore zones.
Monarch CEO Jean-Marc Lacoste says the study was of great interest to Monarch, as it indicates that the tailings will be significantly less harmful to the environment than if they were acid-generating.
Further, the potential to neutralise acid on existing tailings facilities from Wasamac tailings suggests that Wasamac could be an obvious economic choice for several mills.
A Wasamac feasibility study published in 2018 allocated $234-million for the construction of a mill and tailings facilities.
“The company is now considering a new option of bringing ore to a new site for customer milling, which could significantly reduce this portion of the initial capital expenditure for the construction of the mine,” Lacoste explains.