Belfast history

Belfast has an approved mining right that covers 7 198 hectares (ha). The geological model incorporates 616 boreholes. The geological database also includes 113 boreholes outside the mining right area.

Table 12: Belfast operation history

Date range	Company	Material notes
1967	Fuel Research Institute of South Africa	25 boreholes
1969	Trans-Natal Steenkoolkorporasie Beperk	10 boreholes
1975 to 1983	Gold Fields Mining and Development	43 boreholes
2001 to 2003	Eyesizwe	155 boreholes
2008 to 2009	Exxaro	153 boreholes to refine classification and potential box-cut positions
2010 to 2019	Exxaro	133 boreholes to enable detailed box-cut designs and five-year mine plan infill drilling
2019 to 2020	Exxaro	51 boreholes drilled to enable Pit 4 and Pit 4B box-cut delineation and detailed design as well as in the Belfast expansion area

Belfast geology

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 with only very minor areas where the full sequence is developed. Locally, there are mainly three seams being targeted (S2, S3 and S4). The S5 was intersected in only two boreholes in the northern part of the project area. S2, the most prevalent seam, is consistently developed, except in areas where it has been eroded, and has an average thickness of 2.8m dipping gently to the south. Both S3 and S4 are sporadically developed due to erosion and both have an average thickness of 0.6m. Due to the proximity of the northern edge of the Witbank Basin, the primary control of the coal development is the current weathering surface. The deposit is therefore divided by a perennial stream into two Resource blocks under two distinct spurs in the surface topography. There is no indication of pertinent faulting from the borehole information but potential intrusions of dolerite dykes are outlined by regional airborne magnetics, indicating the possible occurrence of regional north-south trending dykes.

There are no known geological structures that may affect the geology or coal seam continuity.

Belfast Resource evaluation

The senior geologist supervises all borehole drilling and is responsible for logging and sampling in compliance with Exxaro’s logging and sampling standards, as well as standard operating procedures. Sampling of boreholes is only conducted after the stratigraphy has been correlated. All samples collected and bagged are registered in a sample sheet, which is also used as a dispatch sheet. The dispatch sheet is signed by the receiving laboratory personnel after ensuring that the number and sample ID on the dispatch sheet matches that of the actual samples to be analysed. Once the laboratory receives and signs the dispatch sheet, it is responsible for safekeeping and storage of that batch of samples.

All coal analysis was conducted at an accredited Bureau Veritas ISO/IEC 17025:2005 laboratory. Emphasis is placed on ensuring data integrity though rigorous procedures and supervision while processing. As part of the assurance and control process, audits are performed internally and externally. Bureau Veritas is South African National Accreditation System (SANAS)-accredited for analytical work and participates in monthly local and international round robins.

The Coal Resource classification methodology is fundamentally based on SANS 10320:2004 and considers borehole spacing, type of boreholes and structural complexity of the Resource. Alignment with SANS10320:2020 in is process. An update of the Resource and geological structural model is scheduled for 2021, incorporating new exploration information obtained during 2019/2020.

Table 13: Belfast Coal Resource reporting criteria

Thickness cut-off (thickness and extraction height considerations)	Quality cut-offs (adb)	Geological loss
Opencast ≤0.5m Underground ≤1.2m*	Ash >50%	5%

*	Current proposed underground exploitation plan was used as a baseline for underground minimum thickness cut-off.

Table 14: Belfast Coal Resource estimation criteria

		Item		Description
Database		Borehole database		acQuire
		Data datum		Cape LO29
		Number of boreholes used for Resource estimation		309 of the 616 do have wash analysis
		Validation		Conducted using queries in acQuire and Excel
		Data compositing and weighting		acQuire
Model		Previous model date		2012
		Last model update		2018, scheduled for 2021 update
		Geological modelling software		Geovia MinexTM
		Estimation technique		Growth algorithm
		Grid mesh size		25m x 25m
		Scan distance		3 000m
		Data boundary		200m
		Model build limits		Upper: limit of weathering and topography/collar Lower: basement/Dwyka
		Model outputs		Roof, floor and thickness grids generated for structure Raw quality grids
		Changes to modelling process		None

Table 15: Belfast Coal Resource classification criteria

Category		Type of boreholes		Borehole spacing		Structurally complex areas		Borehole/ha
Measured		Cored boreholes with applicable coal qualities		0m to 350m		May be more conservative after consideration of RODA		0.08
Indicated		Cored boreholes with applicable coal qualities		350m to 500m		May be more conservative after consideration of RODA		0.04
Inferred		Cored boreholes with applicable coal qualities		500m to 1 000m		May be more conservative after consideration of RODA		0.01

Table 16: Belfast Resource and Reserve statement

Category	2020  (Mt)	2019  (Mt)	Difference in  tonnes  (Mt)	Difference  (%)	Reason for change
Measured	71.3	74.6	(3)	(4)	Mining depletion
Indicated	19.9	20.1	0	(1)
Inferred	34	34.1	0	0
Total Coal Resources (OC/UG)	125.3	128.8	(4)	(3)	Mining depletion
Proved	40.2	42.2	(2)	(5)	Primarily mining depletion
Probable	2.1	1.4	1	50	Change is due to introduction of new pit layout
Total Coal Reserves (OC)	42.3	43.6	(1)	(3)	Mining depletion was off-set by an increase due to pit layout changes

Notes:

• Rounding of figures may cause computational discrepancies.
• All changes more than 10% are explained.
• Mining method: OC.
• Figures are reported at 100% irrespective of percentage attributable to Exxaro.
• The tonnages are quoted in metric tonnes and million tonnes (Mt). Coal Resources are quoted as mineable tonnes in situ (MTIS) and refer to remaining Resources after 31 December 2020 and 31 December 2019.
• Coal Resources are reported on a mineable in situ (MTIS) basis.
• Cut-offs applied as per Resource reporting criteria table.
• Coal Resources are quoted inclusive of Coal Resources converted to Coal Reserves.

Table 17: Belfast RPEEE considerations>

	Item		Criteria		Criteria met		Comment
	Geological data		Data has been validated and signed off by competent person		Yes		Geological structures and depositional extent are considered as well as seam thickness <0.5m (OC) and <1.2m (UG), >50% ash content with coal qualities reported on an air-dry basis
	Geological model		Geological model has been considered and signed off		Yes
	Structural model		Structural model was considered and signed off		Yes		2018
	Mining		Mining assumptions considered and defined		Yes		Opencast and underground
	Assurance		Exxaro internal audits and external audit conducted		Yes		Internal review in 2019 and external audit by EY in 2020
	Economic evaluation		Exploitation study with economic and mining assumptions, including geotechnical and geohydrological assumptions		Yes		Belfast exploitation strategy over mining right (2020)
	Environmental		Reasonable demonstration that environmental approvals can be obtained within the context of local, regional and national governmental legislation		Yes		Environmental management plan, integrated water use licence and National Environmental Management Act licences in place and compliant
	Tenure		Formal tenure must be demonstrated with reasonable demonstration that a mining right approval can be obtained within the context of local, regional and national governmental legislation		Yes		Mining and surface rights in place. Potential land acquisitions for expansions considered. Land access obtained for expansion drilling
	Infrastructure		Assumptions used should be reasonable and within known/assumed tolerances or have examples of precedence		Yes		Existing infrastructure adequate or can be upgraded with new required infrastructure under construction
	Market		A potential market for the product with a reasonable assumption that this market is sustainable		Yes		Primary product qualities suitable for A-grade export market and middlings suitable for domestic power generation

Belfast Reserve estimation

Scheduling of the Reserve is determined using a mining scheduling application (Scheduler) from OCCS, which is the same software used to develop the LoM plan schedule. The geological 3D model used for the Resource statement is referred to as the Reserve geological 3D model.

The geological model is supplied to mining processes in the form of Minex^TM grids. The grids are then imported into a reserving application (Reserver) from the same OCCS software. This application is used to validate the geological information received by checking the integrity of the geological structure and that quality and wash-table values are consistent, and to convert 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, Measured Resource is either not converted or the Measured Resource is converted but downgraded to Probable and the associated risk is clearly stated. Inferred Resources are not converted to Coal Reserves.

Some 0.5Mt of Inferred Resources are included in the LoM plan, representing 1.2% of the LoM plan, and are not considered material. The area with Inferred Resources, on the western edge of the pit, will only be reached towards the end of LoM.

Table 18: Belfast production figures

	Actual 2019	FC 2020	Actual 2020	FC 2021	FC 2022
RoM (Mt)	1.1	3.25	3.24	3.58	3.79

Table 19: Belfast modifying factors considered in converting Coal Resources to Coal Reserves

Modifying factors	Value
Geological loss	5%
Average thickness cut-off	S2 0.8m, S3 and S4 1.0m
Quality cut-offs	No quality cut-offs, economic cut-offs
Mining loss	0.1m
Boundary pillar	0
Dilution	0%
Contamination	0.1m
Mining recovery efficiency	100% (already accounted in mining loss)
Planned average slope angles	90 degrees on hards and on softs
Practical plant yield	88.30%
Strip ratio cut-off	Considered in the reserving process using the economic model to get mining boundaries
Environmentally sensitive areas	100m
Legal	Applicable mining right considered
Social	Applicable communities considered
Geohydrological	Applicable surface and groundwater models considered

Belfast known risks

Weathering impacting on coal seam continuity is a continuous risk, managed through strict grade control and infill drilling practices.

Proactive water management is vital to ensure effective mining production especially within the rainy season.

Belfast operational excellence

The Belfast expansion project currently under investigation will result in extending the LoM. This expansion will include the purchasing of a number of farms to the north of the current mining area. Access to these farms for exploration activities has been secured.

As part of the Exxaro market to resource excellence drive, Belfast Coal will be producing an RB2 product instead of an RB1 product for 2021. The product blend will continuously be reviewed to further optimise the market to resource excellence initiative.

A rigorous operational excellence process is also well entrenched at Belfast Coal where value chain optimisation is actively driven and progress tracked on a weekly basis to ensure the required optimisation of the mine production value chain is realised.