Greenside Colliery produces coal for both the export and local markets. Coal is extracted using the continuous miner method (previously bord and pillar) and is brought to the surface via conveyors to the coal beneficiation plants.

The bulk of the life of mine (LOM) tonnage is sourced from No.4 seam, which is laterally distributed over the whole mine right area. The estimated remaining in situ coal reserves associated with the No.4 seam are 201 million tons, with 124 million tons of Run of Mine (ROM) reserves. A further 47 million tons, 9.2 million tons and 16.2 million tons of mineable reserves are held in the No.1, 2 and 5 seams, respectively.

The No.4 seam is mined using continuous mining methods. Historically, stooping (pillar extraction) and opencast mining methods were also practiced. At Greenside Colliery, the No.4 seam currently produces about 3.6 million tons of ROM coal per annum.

The two beneficiation plants process coal from the No. 4 seam (Greenside Colliery) and the as arising to produce a second project.

Once at the plants, the coal is crushed and washed using dense medium separation (DMS). Any discard and slurry from the process is sent to the coal discard dump. The processed coal is then transported by conveyor to the rapid loading terminal (RLT) from which the coal is transported by rail to international markets via the Richards Bay Coal Terminal (RBCT). Coal is also collected by truck from the beneficiation plant stockpile for sale to the local market.

The DMS consists of 3 by 250 tons per hour (tph) washing modules. Module1&2 shares a common feed bin, fines circuit, discard and product belts and thickener.

The ROM coal is classified into three size fractions and treated separately. The ROM coal is fed at 250 tph onto each feed preparation screen cutting at 0.8 mm; the 50 x 0.8 mm coal is fed to a 900mm diameter DSM (Dutch State Mine) cyclone. The minus 0.8 mm coal is further classified in a hydro cyclone at 0.1mm. The 0.5 x 0.1 mm coal is fed to the spiral circuit. The minus 0.1mm feeds the thickener, which forms the feedstock for the Flotation plant that was commissioned in August 2004.

The 50 x 0.8mm coal is pump fed into a 900mm diameter DSM cyclone. The floats (product) and sinks (discard) report to drain and rinse (D&R) screens for the recovery of magnetite from the products for reuse. The medium recovered from the first stage of the D&R screen returns to the correct medium circuit for re-use. The dilute medium from the second part of the D&R screen is pumped to a magnetic separator for the recovery of medium, which is fed into the correct medium circuit. The discards from the discard D&R screen reports to the discard conveyor belt. The product from the product D&R screen is dewatered in a basket centrifuge to reduce the surface moisture of the coal.

The flotation plant is fed from the DMS plant thickeners into a feed tank. The flotation feed will be diluted using water from the clarified tank to 6% solids before being fed into the Dual-Cell units. The flotation product reports to the product thickener.