Mafube

Coal Resource delineation drilling and five-year mine plan infill drilling (731 drill holes).

Mining ceased at Springboklaagte in 2018 and commenced at Nooitgedacht the same year.

The mine is accessible by tarred regional roads leading off the N4 national road, and a railway line traverses the property in the north, connecting the rail load-out terminal with the Richards Bay Coal Terminal.

Eskom supplies direct bulk power at two points: the main consumer substation adjacent to the coal processing plant and the Overland Conveyor No 3 substation. Potable water is sourced on site per the IWUL specification from three authorised production drill holes at Springboklaagte and one at Nooitgedacht.

Mafube mine is situated near the northern edge of the Witbank coalfield. The coalfield extends about 190km east-west between Springs and Belfast, and about 60km in a north-south direction between Middelburg and Ermelo.

The Witbank coalfield has up to five coal seams in the middle Ecca group sediments of the Karoo supergroup. The Karoo sequence in the area is represented by the Dwyka formation and the middle Ecca with little or no lower Ecca development. The middle Ecca sequence of coal horizons, interbedded with sediments, is highly truncated due to erosion. Only four of the five main coal seams occur within Mafube, and S5 has been eroded.

S4 is confined to the deeper parts (north-west) of the mining area, and S3 is thin and of no current economic significance. An upper sub-seam, designated S2 upper (S2U), is sometimes present. The S2U and S2 lower (S2L) are separated by a thin but distinctive parting (designated S2 parting (P2) with an average thickness of 0.25m). The S2U is fairly thin and consists of poorer quality coal; it is therefore not economic.

S2L is the main economic seam with an average thickness of 4.91m. The quality is variable due to interbedded bright and dull coal plies with some shale and carbonaceous shale, mudstone and occasional sandstone bands.

S1 is thin (average thickness of 0.75m) and continuous throughout the Mafube area. It lies approximately 0.5m below the S2L. Two minor seams occasionally occur below S1 (designated S1L and S1LL). They are, however, of no economic significance.

Mafube has typically used conventional core drilling (diamond drilling) for most of the holes drilled. This produces a 63.5mm diameter solid core for logging and sampling. Full core is usually produced once competent strata have been intersected. Open-hole drilling techniques are employed for the near-surface OVB material (usually by-products of current day weathering). The core is measured, any core loss is identified and recorded, and important geological units are marked off before logging commences.

The core is logged by the field geologist responsible for Mafube exploration drilling. Core logging data is recorded manually on the borehole coding sheets (“logging sheets”) using a logical letter coding system (“Dictionary of Codes”). This data is then captured into Excel and imported into the acQuire database where standard QAQC routines ensure the correctness of the data.

Since 2019, most vertical surface drill holes have been wireline logged for the purpose of enhanced seam roof and floor mapping to delineate areas of seam floor rolls, seam thinning, seam thickening and seam pinching. Photographs of the core are taken after marking the core. Geological information is captured on log sheets with lithology captured up to centimetre details. Sampling is conducted on site with the aid of wireline logs as per Mafube sampling standard.

Environmental management plan, IWUL and NEMA licences in place and compliant. Application for authorisation in terms of the NEMWA or in terms of NEMA for the mining of Pan 11 (Rooipan) has been prepared and submitted. The submission was made after the completion of the required technical specialist studies. Final EIR/EMPr was submitted on 30 October 2023 to the Department of Mineral Resources and Energy (DMRE) and on 20 November 2023 to the DWS. Reports are under review for approval.

The addition of the designs for the new water uses (PCD) necessitated withdrawal and relaunching in the eWULAAS to amend water uses. Approval from the DWS moved to the third quarter of 2024.

Scheduling of the Reserve is determined using a mining scheduling application (Scheduler) from OCCS, which is the same software used to develop the LoMP schedule.

The geological model is supplied to mining, project and technology in the form of Minex™ grids. The grids are then imported into a reserving application (Reserver) from the same OCCS software. This application validates the geological information received by checking the integrity of the geological structure and its quality, ensures wash table values are consistent, and converts the geological 3D model into mineable block sizes.

Indicated Resources are generally converted to Probable Reserves and Measured Resources to Proved Reserves after consideration of all applicable modifying factors. If one or more of the modifying factors have not been fulfilled, the Measured Resource is either not converted, or the Measured Resource is converted but downgraded to Probable (as is the case with Rooipan) and the associated risk is clearly stated. Inferred Resources are not converted to Coal Reserves.

Modifying factors