This report describes the proposed design for an integrated lithium hydroxide converter operation fed by spodumene concentrate from the Georgia Lake Lithium Project in Northwest Ontario, Canada, as presented in a Preliminary Economic Assessment with an effective date of 30 October 2020.
Report context
The technical report, titled "Preliminary Economic Assessment for an Integrated Lithium Hydroxide Operation from the Georgia Lake Lithium Project, Northwest Ontario, Canada," was prepared with an effective date and submission date of 30 October 2020. The study presents a preliminary economic assessment for an integrated operation that would combine the Georgia Lake Lithium Project with a lithium hydroxide converter. The report covers a processing route that includes beneficiation, pyrometallurgy, hydrometallurgy, and downstream conversion to lithium hydroxide monohydrate.
Processing route
Plant Feed
The processing route begins with spodumene concentrate feed to the converter plant. The report describes a plant feed stage as the entry point for the downstream process, with the concentrate sourced from the Georgia Lake Lithium Project.
Calcination
The concentrate is subjected to calcination as the first pyrometallurgical step. This stage is designed to induce the phase transformation of spodumene from its natural alpha form to the more reactive beta form, which is required for subsequent processing.
Sulphating Roast
Following calcination, the material undergoes a sulphating roast, also referred to as acid roasting. In this step, the calcined spodumene is mixed with sulphuric acid and roasted at elevated temperature. This converts the lithium in the spodumene to a water-soluble lithium sulphate form.
Lithium Sulphate Leaching and Residue Removal
The roasted product is then subjected to a water leach to dissolve the lithium sulphate. The leach liquor is separated from the insoluble residue, which is removed from the process. This step is designed to produce a clarified lithium sulphate solution for further purification.
Impurity Removal
The clarified lithium sulphate solution undergoes an impurity removal step to precipitate and remove undesirable elements. The report does not specify which impurities are targeted in this design.
LiOH Reactor
The purified lithium sulphate solution is then directed to a lithium hydroxide reactor. In this step, the lithium sulphate is reacted with a reagent, typically sodium hydroxide, to convert the lithium to lithium hydroxide. This reaction also produces sodium sulphate as a by-product.
Glauber's Salt
The report identifies Glauber's salt as a distinct process step. Glauber's salt is the decahydrate form of sodium sulphate. This step is designed to manage the sodium sulphate by-product from the LiOH reactor, likely through crystallisation.
LiOH Crystallisation
The lithium hydroxide solution is concentrated and crystallised. This step is designed to produce lithium hydroxide monohydrate crystals of suitable purity and particle size distribution. The report does not provide details on crystallisation conditions or yield expectations.
Product Drying
The crystallised lithium hydroxide monohydrate is dried to remove surface moisture. This step is designed to produce a stable product with the required moisture content for subsequent handling.
Product Drying and Micronising
The dried lithium hydroxide may be further processed through a micronising step. This is designed to adjust the particle size distribution of the final product to meet customer specifications, particularly for battery-grade applications. The report does not specify the target particle size range.
Product Bagging
The final product is bagged for shipment. The bagging step is designed to protect the product from moisture and contamination during storage and transport.
Waste and By-Products
Sodium Sulphate Crystallisation
The report identifies sodium sulphate crystallisation as a by-product recovery step. This is separate from the Glauber's salt step described earlier, though the relationship between the two is not defined in the report.
Tailings Disposal
The processing route includes a tailings disposal step for the residue from the leaching stage. The report does not describe the disposal method (e.g., dry stack, paste, or conventional wet tailings).
Key reported parameters
| Parameter | Value | Units | Basis |
|---|---|---|---|
| Plant feed | Spodumene concentrate | , | Proposed design |
| Primary conversion route | Sulphation (acid roasting) | , | Proposed design |
| Calcination step | Yes | , | Proposed design |
| Sulphating roast step | Yes | , | Proposed design |
| Water leach step | Yes | , | Proposed design |
| Impurity removal step | Yes | , | Proposed design |
| LiOH reactor | Yes | , | Proposed design |
| Glauber's salt step | Yes | , | Proposed design |
| LiOH crystallisation | Yes | , | Proposed design |
| Product drying | Yes | , | Proposed design |
| Micronising | Yes | , | Proposed design |
| Product bagging | Yes | , | Proposed design |
| Sodium sulphate crystallisation | Yes | , | Proposed design |
| Tailings disposal | Yes | , | Proposed design |
Project website: https://avalonadvancedmaterials.com/avalon-announces-the-commencement-of-feasibility-study-at-lake-superior-lithium-project-ontario/
Technical qualifications
The report is a preliminary economic assessment (PEA) and therefore does not demonstrate that the project can be developed as described. The processing information is presented at the conceptual or pre-feasibility level and would require additional metallurgical testwork and engineering studies to progress to higher levels of confidence. The report does not provide actual operating data from a commercial-scale plant, as the described processing route for the Georgia Lake Lithium Project converter has not been demonstrated in a commercial operating environment. The report notes that the author was responsible for peer review of the metallurgical testwork and recovery methods sections. The design parameters, equipment selections, and process flow arrangements described in this article are derived from the original technical report and show the proposed design presented therein; they should not be interpreted as a description of an existing operating facility.
Source: Preliminary Economic Assessment for an Integrated Lithium Hydroxide Operation from the Georgia Lake Lithium Project, Northwest Ontario, Canada, effective 30 October 2020, Section 13 (Mineral Processing and Metallurgical Testing) and Section 17 (Recovery Methods).
