The deposit defined within the Minim Martap Project Resource is a Bauxite Deposit. The formation of bauxite within a lateritic setting requires the presence of Al bearing ground rock, an oxygen-rich groundwater, a warm temperate – tropical environment with high rainfall levels, and time.

The presence of bauxite relates predominantly to the reduction of all other elements from the lateritic section, especially Si and Fe, leaving Al present within the very stable series of Al hydroxides of Gibbsite and Boehmite. Bauxite forms in the top of the lateritic profile where it is preserved (the top 10-15m), overlying often a 2-5m transition zone), and derived from the underlying sediments. The surface of the bauxite zone is dominated by bauxite rubble, with little Fe oxides and other minerals present – it is clearly a surface that is undergoing physical erosion over time and it is highly probable that this surface has reduced in level quite significantly since the period from which the current plateaus were meant to have been preserved.

The bauxite zone in the Cameroon Ngaoundéré region is predominantly 10-15m thick, and within it the grades of Al can vary between 35-62% Al as well as 5-30%Fe. These elements are the two main constituents. The Ngaoundal bauxite is formed from the bauxitization of a basalt and this has meant significantly lower Al Grades, higher Fe grades and very low residual Si values. The Minim Martap and Makan bauxite is formed over more Al rich basal rocks (granites, feldspar rich gneisses) and Al grades are high, Fe grades lower, and residual Si values higher.

Mining method selected and other mining assumptions
The mine design, upon which the Ore Reserve estimate is based, is simple, edge-to-edge strip mining, open-pit and resulting in very low structural geotechnical risk. The bauxite will be mined from the tops of plateaux and as such the development of significant pit walls is not a feature. As such it is not anticipated that significant structural geotechnical investigations or pit slope stability analysis will be required for this project. Mining productivity has been based on benchmarked data and equipment manufacturer input.

The PFS strategic mine schedules utilised inputs derived from the Scoping Study to refine the optimal mine areas. This resulted in a consolidated mining area about the three sub-plateaux of Beatrice South, Raymonde-East and DanielleCentral. Detailed, quarterly, mining schedules were derived from the strategic schedules.

The high-grade ore and near surface nature of the bauxite deposits lends itself to simple, industry typical mining methods, at low cost and with low strip ratios. Due to the simple nature of mining it is anticipated to be conducted as an owner operation using conventional mechanised equipment including surface-miners, bull dozers, front end loaders, haul trucks and other typical ancillary mining equipment. The potential for mining contract operations will continue to be investigated as development progresses.

The ore presents with favourable physical properties and requires no beneficiation, washing or screening. Test-work conducted with bulk samples on wet and dry washing processes6 and to define material handling parameters7 confirms the mine can produce DSO with world class grades, without any beneficiation. Material testing outcomes have been used to confirm the suitability of the supply chain solution and inform the physical technical specification of the product for potential off takers and shipping.

Rock strength testing on over 500 samples across the priority mining areas and throughout the depth profile confirms suitability of surface miners and negates the need for drill and blast. The physical testing programme included strength testing using a point load testing machine and has confirmed the rock strength to be at the optimal range for efficient operations of surface miners. The surface miners are expected to mill thirty to fifty-centimetre (30-50cm) cuts along the highly homogenous and sub-horizontal orebody and deposit 75mm top size milled material in windrows along the mining bench. Front end loaders (FELs) will load mining trucks which will dump at plateau specific ROM pads, stockpiled in accordance to grade profiles. This method eliminates the need for blasting and decouples the on-plateau mining equipment from the road haulage trucks whilst minimising rehandle.

Groundwater conditions have been assessed from the ongoing infield water monitoring and testing programme for the assessment of pit dewatering methodologies. Current baseline and hydrology assessments by specialist subconsultants confirm perched water tables within the plateau with the bauxite mostly remaining above the zone of saturation. High permeability rates suggest rapid draining of any saturated bauxite. It is intended to advance dewater the plateaux immediately prior to mining and drainage designs have been integrated with the mine plans. Acid-base accounting analyses from the acid rock drainage programme showed only two sites are possible locations for limited acidic water generation. The alkalinity of the soils and bauxite appear to successfully buffer any acid generation.

The Ore Reserve estimate is based on the production target and forecast financial information derived from a detailed mining schedule modelled at a production rate of 5 Mtpa, ramping up from 4 Mtpa after 2 years of operations, in line with rail line upgrades as disclosed in the PFS announcement. This mining schedule was completed after the PFS8 , which presented the production target and forecast financial information based on a 4 million tonnes per annum mining schedule which was scaled and extrapolated to represent the ramp up to 5 million tonnes per annum in year 2026. Differences, which both the Company and the CP for Ore Reserves consider immaterial, between the material assumptions for the Ore Reserve estimate and the production target and financial forecast from the PFS are attributable to adjustments in the mine scheduling.