Corazon Mining Ltd (ASX:CZN, OTC:CRZNF) has received further positive metallurgical test-work results from its Lynn Lake nickel-copper-cobalt sulphide project in Manitoba, Canada, where ore-upgrading presents the potential to reduce costs and increase reserves of a future mining operation.
As part of ongoing metallurgical test-work, Corazon has completed a second phase of ore-upgrading tests using two innovative processing technologies - ore sorting and coarse flotation (via HydroFloat).
These technologies target the removal of waste material from low- to medium-grade mineralisation, which can result in a higher processing feed grade and reduced costs.
Such processing innovation is a key component of Corazon’s strategy to transform Lynn Lake into a long-life, low-cost, nickel sulphide mining operation.
Promising results
The current metallurgical test-work has achieved promising results that will be integrated into scoping study processing flow charts.
This test-work is part of Corazon’s integrated strategy of optimising the mining and processing methods to take advantage of the large amount of low-to-medium grade mineralisation at Lynn Lake.
By bulk mining the project’s sulphide deposits, there’s potential to substantially reduce mining costs and possibly result in a lower overall feed grade.
Lynn Lake was successfully mined for 24 years before it was closed in 1976. Historically, the orebodies at the project were selectively mined and geologically high-graded, resulting in very good metallurgical performance but this also involved high mining costs and it left a significant amount of unexploited resources.
Corazon has observed good continuity of the mineralised envelopes at low to medium grade, with the high-grade mineralisation being discontinuous and poddy in form. It says that mining a larger and more continuous ore zone reduces stoping costs and the amount of costly underground infrastructure required.
While there is the added cost of handling and processing of lower-grade material or waste, recent developments and improved technology make the concept of economically removing waste material from the processing feed stream considered possible.
The ore at Lake Lynn was historically processed via conventional flotation, which delivered very good recoveries for nickel, copper and cobalt. Corazon has since achieved improved recoveries and concentrate grades compared to those historically reported.
The company’s metallurgical test-work is assessing an upgrade of the feed grade pre-flotation via the removal of waste material incorporated within the mineralisation. The pathway to looking at pre-flotation ore upgrade has been driven by geology and improved mining practices.
Both the historical recoveries and concentrate grades, along with Corazon’s work to date, suggests the Lynn Lake mineralisation performs very well via flotation. Such ore types typically have no problem producing high-quality battery-grade products.
Looking ahead
Based on the positive outcomes of the current test-work, Corazon will consider the use of both ore sorting and coarse flotation technologies at Lynn Lake and for the scoping study work that is now underway.
Definitive test-work for all ore types will be continued and refined. The company is now reviewing what additional test-work is required, which will depend on the amount of metallurgical sample the company has at its disposal in Perth.
In consideration of the metallurgical test-work results and the analysis of the resource grade domains, changes to Lynn Lake’s JORC resource estimates are in progress.
It’s worth noting that 80% of the current resources are in the measured or indicated JORC category (total contained metal of 116,800 tonnes of nickel, 54,300 tonnes of copper and 5,300 tonnes of cobalt), with much of the resource area drilled out and ready for mining.