Canadian miner Giyani Metals provided results of a feasibility study (FS) conducted for its K.Hill battery-grade manganese project, located in Botswana, last month.

The FS results followed life cycle assessment – prepared by environmental consultants Minviro – published in late September, which calculated the project’s global warming potential (GWP) and concluded that the main impact driver is the consumption of electricity from the national grid in Botswana, corresponding to about 37% of total GWP of 3.2 kg carbon dioxide equivalent (CO2eq) per kg of high purity manganese sulphate mono-hydrate (HPMSM), of which Scope 1 and Scope 2 emissions amount to 1.4 kg CO2eq per kg HPMSM.

Given the assessment, the “excellent solar radiation conditions” in Botswana and the miner’s goal of being a low-carbon supplier of critical lithium-ion battery raw materials for the electric vehicle (EV) industry, Giyani identified solar power generation as an opportunity to further reduce the project’s already low-carbon footprint.

The project plan includes a 4.5 MW photovoltaic (PV) solar plant, and Giyani is assessing various options to further reduce the GWP for K.Hill and to develop a roadmap for decarbonisation.

The 4.5 MW plant will be located on a 7.6 ha area 1.2 km west-north-west of the Kanye municipal borehole. This location was selected to take advantage of the relatively flat topography west of the mine, and to position the solar plant outside of an area that would be affected in the unlikely event of any dust plume coming from the mine, for which dominant wind direction and speeds were accounted.

The miner noted that the Botswana Power Corporation (BPC) issued a letter dated June 30 this year agreeing to provide power supply infrastructure for the project.

A total load demand of about 15 MVA is expected for this development phase. BPC will, however, provide for a total load demand of 30 MVA in the form of a 132/33 kV substation, fed through a new 19 km, 132 kV transmission line from the Mmakgodumo substation situated on the northern outskirts of Kanye, along the Kanye-Lobatse bypass road.

A new 132/11 kV substation will be located within the vicinity of the K.Hill site. The supply will be sized to accommodate a future potential expansion of the production capacity of the project.

Motor control centre (MCC) nodes will be serviced at an 11 kV level through local ring main units. Electrical users have been functionally grouped into MCC nodes according to the process flow diagrams and considering the geographical location of consumers. The MCC nodes will be connected to the 11 kV supply network.

FS Results

The FS was prepared by consulting engineers SRK Consulting, as lead, on an integrated mining and processing operation for the on-site production of HPMSM directly from manganese oxide ore mined at K.Hill.

HPMSM is a refined precursor material used in the production of cathode powders for lithium-ion batteries that are deployed in EVs.

K.Hill’s total indicated resource of 2.1-million tons – estimated by SRK in February this year – was evaluated for the purpose of the FS. Almost 100% of the indicated resources have been converted into two-million tons of probable reserves.

The inferred resource of three-million tons for K.Hill – estimated by SRK – is in the process of evaluation to be upgraded into the indicated resource category.

New mineral resource estimates for K.Hill and the nearby Otse manganese oxide prospect are currently targeted for completion in the first quarter of next year.

“Our flagship K.Hill manganese project has the potential to be one of the most significant and largest battery-grade manganese producers globally. The FS shows how far the scope of the project has developed since the April 2021 preliminary economic assessment, and is the next step to bringing this project into production. These results demonstrate the robust economics of K.Hill, with our ongoing work also highlighting the expansion and optimisation potential,” explained Giyani Metals executive chair Jonathan Henry.

He added that Giyani has an early-mover advantage to meet the growing demand for HPMSM from the EV sector, which is prioritising responsible and low-carbon producers outside the dominant Chinese supply chain.

Giyani’s hydrometallurgical process – which treats captive ore without the need for calcining or electrorefining – saves both cost and carbon emissions. This is evidenced by the results of the recent life cycle assessment.

“Alongside the optimisation work that will be completed after the FS release, which will review opportunities to enhance the project’s value, we continue to evaluate the 3.1-million tons of inferred resources at K.Hill and potential additional resources at nearby Otse still to be consolidated into the project plan, with the view to extend K.Hill’s operating life and production capacity significantly.”

In parallel to the FS work, the team has progressed the construction of a demonstration plant, and it remains on track to produce HPMSM samples for testing by potential offtakers in the second quarter of next year.