Seriti Resources holds a 90% interest in Seriti Coal Pty Ltd, while an Seriti Coal Management and Employee Trusts and Seriti Coal Community Trust each hold a 5% interest in Seriti Resources Holdings Pty Ltd..
Seriti, through its operating subsidiary, Seriti Coal Pty Ltd, operates three large- scale, opencast and underground thermal coal mines namely, New Vaal, New Denmark and Kriel Collieries.
Summary:
The Highveld Coalfield in the Mpumalanga Province of South Africa is situated on the northern part of the main Karoo Basin. The Karoo Supergroup can be divided into the Dwyka, Ecca, Beaufort, Stormberg and Drakensberg Groups.
The Highveld Coalfield is underlain by a thin sequence of Dwyka and Middle Ecca strata lying on an undulating floor composed of felsites, granites, and diabase associated with the Bushveld Complex.
The Vryheid Formation of the Ecca Group, where the coal occurs, conformably overlies the tillite with minor conglomerates, sandstones, shales and coal. In the Highveld (and Witbank) coal fields, the glacial deposits of the Dwyka Group are directly overlain by rocks of the Vryheid formation, as the Pietermaritzburg formation is absent in these coal fields. The overlying Volksrust Formation is also either not developed or completely eroded away in the central Mpumalanga coal fields.
Pre-Karoo dolerites have greatly intruded the geological sequence of the Highveld Coalfield. There are two main dolerite sills in the coalfield, with more extensive thinner sills 1.5 m to 15 m thick. Where a dolerite sill has intruded, the seam is faulted, resulting in a vertical throw ranging from 6 to 25 m.
A major dolerite sill of up to 14 m is generally situated below the No. 2 seam in the Pit 4, 23 and 23 extension areas.
The basin depth is approximately 300 m, with the coal zone approximately 70 m thick. Five major coal seams occur in the Highveld, numbered from the bottom upwards, No. 1, 2, 3, 4, and 5. The coal seams are generally described as follows:
- No.1 Seam is thin and mainly discontinuous
- No.2 Seam is approximately 1.5-4 m
- No.3 Seam is thin and discontinuous
- No.4 Seam is 1-12 m, laterally continuous
- No.4 Upper Seam is 1-4 m thick and is separated from No.4 Lower Seam which is 4-12 m thick by sandstone
- No.4A Seam occurs above the No.4 Upper Seam
- No.5 Seam is 1-2 m thin.
The Kriel Colliery reserves are situated on the northern margin of the Highveld coalfield. The majority of the coal mined at Kriel Colliery is from the No.4 Seam. The total thickness of the No.4 Seam in the Kriel coal field is generally between 4 and 5 m thick, where the top seam attains a thickness of 1.5 to 2 m. The No 4 seam is regionally overlain by a thick interlaminated shale-sandstone/siltstone and underlain by a typical white Ecca sandstone layer. Glauconitic sandstone, indicative of transgressive marine periods, is present above the Nos. 4 and 5 coal seams, forming useful stratigraphic markers.
Proven coal reserves in the Kriel Coalfield are the No 2, 4 and 5 seams, but only the No 4 seam is economically extracted. The coal is ranked as low-grade bituminous steam coal and the depth of the coal seam ranges from 6 m to 85 m below the ground. All coal historically and currently produced is dedicated to the Kriel Power station.
Commodity Production
Kriel mine was acquired from Anglo American in March 2018 by Seriti Resources Holdings Proprietary Ltd.
As a result 2018 full year production numbers have not been reported.
Starting from 2020 Seriti Resources reports average annual production of 5 Mt.
| Commodity | Units | 2023 | 2022 | 2020 | 2019 | 2017 | 2016 | 2015 |
|
Coal (thermal)
|
Mt
| ....  | .... | .... | 4.6 | 5.4 | 6.3 | 6.2 |
All production numbers are expressed as ROM coal.
* Production numbers were reported as 'Average annual'