Grid Metals Releases Positive Metallurgical Test Results for Donner Lake Lithium

Grid Metals Corp. (TSXV:GRDM)(OTCQB:MSMGF) announced positive initial results from metallurgical tests carried out on drill core samples from its 75% owned Donner Lake Lithium Property. Samples were taken from the Main and Northwest Dykes that together are the subject of an initial NI 43-101 resource estimate currently underway.


  • Strong lithium recoveries (expressed as Li2O) to concentrates of 76.9% (Northwest Dyke) and 74.1% (Main Dyke) were achieved using standard grinding and direct flotation methods.
  • Both composite samples produced high purity lithium concentrates suitable for sales to more demanding, higher margin industries – 6.2% Li2O for the Northwest Dyke and 5.7% Li2O for the Main Dyke.
  • Head grades (as Li2O %) for the Main and Northwest Dyke composite samples were 1.46% and 1.34 %, respectively, approximating average exploration drilling grades obtained in Grid’s drill campaigns.
  • Iron content of the concentrates was low.
  • The mineralogical analyses completed as part of the testwork program found that 89.3%-95% of the main lithium carrier by grade was spodumene. Spodumene is the most concentrated carrier of lithium.
Donner Lake project location map

Mineralogical assessment and a bench scale metallurgical test program on composites representing a number of the drill core intervals were completed at XPS Expert Process Solutions, a GLENCORE Company, in Sudbury, Ontario (XPS).

XPS is an experienced provider of metallurgical testwork to the lithium industry. The mineralogical study positively identified the main lithium-bearing mineral in the samples as spodumene, the preferred mineral of concentrate feedstock for conversion facilities globally. The bench scale metallurgical testing produced excellent recoveries and marketable concentrate grades.

The report was successful in recommending an optimal grind size to maximize recovery from both of the Main Dyke and the Northwest Dyke composites.

The report concluded that standard flotation was the best method for recovering lithium from the samples. Testing of Heavy Liquid Separation, as an initial evaluation of the Dense Media Separation process, was conducted and it was determined that this process would not be of material value for enhancing lithium recovery.

Grid anticipates announcing the results of an initial resource estimate from the Donner Lake Lithium Property in the coming weeks. They have also started field operations to follow up on lithium exploration targets – identified by lithogeochemical data collected during the summer/fall field program in 2022

With a successful initial metallurgical program now completed, Grid Metals plans to continue additional metallurgical testing in the future, and has an upcoming program of complementary metallurgical testwork to be completed at the Tanco Mine. The initial work at Tanco will provide analysis of the potential recovery of Donner Lake material from the Tanco lithium spodumene circuit. Tanco is one of two currently producing lithium operations in Canada and Grid has a Memorandum of Understanding with Sinomine Canada regarding toll milling of material from Donner Lake at the Tanco Mine.

In addition, they will follow up on recommendations from the XPS report to complete variability testing on future composite samples from the Main and Northwest Dykes.

We are pleased to now have tangible test results confirming that spodumene is the dominant lithium mineral and that standard flotation processing appears to be effective at recovering lithium to a marketable concentrate.  This is another positive initial milestone for the Donner Lake Lithium Property.Robin Dunbar, CEO, Grid Metals.


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