Reclamation of aluminosilicate by-products from the Nemaska Lithium plant

Context

The Nemaska Lithium commercial plant is currently in the detailed engineering stage . Production should begin in early 2020 to reach 30,000 tonnes of lithium salts. Lithium purification in the Nemaska Lithium plant will generate by-products that are potentially valuable. The process first involves thermal conversion and acidulation of the spodumene concentrate from the Whabouchi mine, which produces a solution of lithium sulphate and aluminosilicate. Lithium purification is then done in successive steps that produce a gypsum paste. Both by-products, aluminosilicate and gypsum paste, can be recovered separately or mixed together.

Description of the challenge

According to a report produced by Nemaska Lithium, the expected production of aluminosilicate will be 250,000 tons / year (25% wet basis) while the production of gypsum paste will be 30,000 tons / year (wet base 22%) . The 80% granulometry would be 100 μm for both by-products.
A possible use would be in the production of cement, which potentially involves a long process of certification to meet the standards of construction. The objective of the project is to find a reclamation option that would further enhance and value the aluminosilicate and gypsum by-products.
The dryness of the by-products does not allow them to be shoveled to load them and a waterproof tipper should be used for transport. Depending on the proposed use, it would be possible to reduce or dry the moisture content. What level of humidity should the by-products have at the process output? Are the particle size and composition adequate?
Logistically, what quantities will have to be stored, which means of transport will be preferred and which means of handling and loading will have to be put in place? These are some of the questions that the challenge should address.

Constraint(s)

Nemaska Lithium ideally wishes to take care of the entire volume of by-products as soon as the commercial plant starts, scheduled for the second half of 2019, while minimizing seasonal variations.
To do this, the by-product processing steps at the plant must be minimized as well as the process impacts.
Use near Shawinigan will be prioritized to reduce transportation costs and their impact in terms of GHG emissions. Nemaska Lithium already has certain targets on nearby land that could be made available to the company that would ensure the valuation of these by-products. The proposed solution must also take into account the logistics of handling and loading around the plant to facilitate its integration into the plant development and operations plan.
Lastly, Nemaska Lithium aims to implement the proposed solution at zero cost while promoting the development of a local or regional company that would benefit from the proposed business model.

Estimated duration of the project:24 months