PLATINUM GROUP METALS LTD

1.12 Mining Methods

The Waterberg Project will be a 400,000 tonnes per month (tpm) (400 ktpm) mechanized underground mining operation accessed via declines. The mine design is based on using sublevel Longhole and backfilling the mined voids with paste backfill.

The mining methods for the DFS Update are similar to those in the 2019 DFS, with adjustments to the Central and South Complexes. The North Complex mine design remains unchanged.

The main adjustments to the Central and South Complexes are as follows:

• Reduced the mining COG in the Central Complex from 2.5 g/t 4E to 2.0 g/t 4E based on updated COG input parameters.

• Reduced the mining COG in the F-South (in the South Complex) from 2.5 g/t 4E to 2.0 g/t 4E based on updated COG input parameters.

• Increased the minimum stope footwall (FW) angle to 42o.

• Reduced the minimum stope hanging wall (HW) angle to 30o.

• Reduced the sublevel spacing for the upper mining block in the Central Complex to 20 m from a combination of 20 m and 40 m to allow the operation to gain experience with the mining method and processes.

• Reduced the sublevel spacing in the T-Zone to a consistent 20 m (from a combination of 20 m and 40 m throughout) to increase resource recovery and minimize mining risk on the narrow ore body, with a 42o FW angle adjustment.

• Adjusted the T-Zone decline and FW infrastructure placement to avoid a fault that parallels the T-Zone resource.

The lower mining COG in the Central Complex resulted in an 88.4% increase in the Central Complex reserve tonnage (from 70.1 Mt to 132.1 Mt). The increase in Central Complex reserves presented the opportunity to increase the Central Complex production rate to 400,000 tpm and delay the capital cost of developing the South Complex and North Complex. The DFS Update includes developing and mining the Central Complex at 400,000 tpm followed by developing and mining the South Complex and North Complex concurrently at a combined 400,000 tpm (the South Complex will produce approximately 100,000 tpm and the North Complex will produce at approximately 300,000 tpm). The South Complex underground workings will be accessed from the Central Complex underground workings, eliminating the requirement for a South Complex portal box cut.

The Waterberg Project was divided into the following three mining Complexes.

• The South Complex that includes T-Zone and F-South.

• The Central Complex that includes F-Central.

• The North Complex that includes F-North, F-Boundary North, and F-Boundary South.

A plan view with the production areas projected to surface is shown in Figure 1-3 and a longitudinal view of the zones, looking approximately northwest (looking from the footwall), is shown in Figure 1-4.

Waterberg Technical Report