St-Georges Eco-Mining Corp.: Complete Recuperation of Lithium in Leach

St-Georges' patent pending leaching technology achieved 100% leaching of lithium while not affecting the majority of the solids. 88% of the initial feed material is unleached which helps with chemicals consumption and tailings disposal.

The patent pending mix of nitric and citric acids being used do not require high temperature and high pressure and no calcination is required. The objectives of the technology development was simply to have the lowest chemical cost impact.

The impacts on the Bonnie Claire Deposit of the first phase of the process that includes classification, concentration and leaching at atmospheric pressure and low temperature has shown an average concentration gain from 963 ppm Li to 8,025 ppm Li, or a gain of 8,333 percent.

St-Georges is currently testing different calibration and improving on its selective leaching in order to target only the recuperation in the leach of the lithium and magnesium and achieve better grades in the leach.

Potential Fertilizer By-Products

In addition to the lithium, the selective leaching collects mainly the salt family elements such as Sodium (Na), Magnesium (Mg), Calcium (Ca) and items like carbonates. The company believe that this could lead to-possible development of fertilizer by-products in the nitrate family that would potentially positively impact the economics of the Bonnie Claire project.

Current On-Going Developments

The next tests to be started this week will focus on reducing the total time of contact and we expect that the selectivity will be increased. In addition, St-Georges is in the process of purchasing a electrolysis unit to make LiOH to be added to the pilot plant with a further focus on using less chemicals. Work with various vendors of resins has been initiated to optimize the lithium purification steps prior to lithium hydroxide production.

Phase 1 Confidential Report

The phase 1 confidential report is currently being independently reviewed and a final public summary should be disseminated within 45 days. Detailed tests result and confidential information related to the process flow-sheet has been provided to Iconic management. For details and guidelines regulating the relation between Iconic and St-Georges, please read December 7, 2017 press release "Licensing Technology Agreement with Iconic Minerals".

Summary of the proposed industrial process

Developmental testing has results in 100% of the lithium leached to be repeatedly recuperated using the patent pending leaching technology developed by St-Georges.

Below are the steps tested in the course of Phase 1 of the development of the process.

Step 1: Screening

The lithium material is being screened out to remove pebbles and other coarse material like calcium.

(Independent testing and review of this stage was performed during the course of the months of March and April 2018 by SGS Lakefield laboratory in Ontario)

Step 2: De- Agglomeration

The agglomerated material is being fed into a roll grinder to break down the feed into the original fine particles before drying.

This was also done and reviewed by SGS Laboratory. After these 2 initial steps review, SGS performed an XRD and chemical analysis for each of the elements and crystalline forms.

Step 3: Concentration

Two approaches were developed and tested. Air classification and flotation concentration. These co-exist as linear task A and B of the concentration step at this stage. St-Georges is currently working on eliminating one of the sub-tasks with the hopes of drastically reducing costs and processing time.

Task 3a: Air Classification

In this step the material is separated by density and particle size. In the particular case of the Bonnie Claire material, the lithium is contained in the superfine particles. These particles are too fine to be screened.

Independent review and testing of Task 3a were performed in the scope of the month of November 2018 by the laboratories of Netzsch Premier Technologies LLC of Exton, Pennsylvania. The resulting material was reduced by 55% with a cut-off at 5 microns.

The resulting material was sent by Netzsch for chemical analysis to the laboratories of the Centre de Technologie minerales et de plasturgie Inc. (CTMP) at Tedford-Mines in Quebec.

The lab results confirmed that 100% of the lithium remained in the resulting concentrate when properly de-agglomerated.

Task 3b: Floatation Concentration

The CTMP labs performed, at the demand of St-Georges, a traditional froth floatation with deionized water. These tests were unsuccessful forcing the company metallurgists to adopt a different approach.

St-Georges patent pending technology using a silicate salt saturated medium will be independently reviewed and tested with bulk material within the first part of the month of April by CTMP.

Step 4: Selective Leaching

Using St-Georges' patent pending acid mix solution of nitric and citric acids, the CTMP reviewed and independently tested 2 batches of material from the Bonnie Claire lithium deposit.

Leach test 1:

Material from this initial test was passed through tasks 1 and 2 but skipped classification and concentration. The results are:

100% of the lithium was leached at atmosphere pressure and low temperature. The total leach time was of 1 hour resulting in 12% of the initial total mass. The company set-up and intends to improve on that result.

Leach test 2:

Material from this leach test was passed through tasks 1, 2 and 3a. 100% of the lithium was leached at atmosphere pressure and low temperature. The total leach time was of 1 hour resulting in 12% of the initial total mass.

Optimization of these tasks should yield results in industrial settings that would reduce the total mass to a target percentage below 5%

Joel Scodnick, P.Geo, St-Georges Vice-President Exploration is a qualified person under NI 43-101 and has reviewed and approved the technical content of this release.


ON BEHALF OF THE BOARD OF DIRECTORS

"Enrico Di Cesare"
ENRICO DI CESARE, DIRECTOR & VICE-PRESIDENT RESEARCH & DEVELOPMENT



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