All photos by Nicola Theunissen
Afrimat has spent a substantial amount on capital projects and plant expansions since they acquired Glen Douglas six years ago. The sub-base plant has been one of these projects.
In the heart of the quaint Henley on Klip community lies the second biggest quarry operation in South Africa: Glen Douglas mine.
The dolomite quarry near Meyerton, approximately 50km south of Johannesburg, has been running for nearly 70 years. Afrimat took ownership thereof in January 2011, taking it over from Exxaro Resources.
According to Willem Hattingh, mine manager for Glen Douglas, they have spent a substantial amount on capital projects and plant expansions since Afrimat acquired the mine six years ago.
“ On the plant side, we completely replaced the mining fleet and front-end loader fleet. We also upgraded the super sand section of the operation. With a spike in the demand for super sand, the R25-million capital expansion project was commissioned in 2015,” Hattingh informs.
One year later, Glen Douglas constructed a sub-base plant for road material.“ We were crushing base layer material through a mobile crusher with one of our sister companies, but we realised there was a stable, consistent market for sub-base materials, so we erected the fixed plant.”
Agility to respond to market demand
Product demand has been stable with no rapid spikes or decreases in demand over the past five years.
Since acquiring the quarry, the team at Glen Douglas has put strong emphasis on operations, maintenance, and production. Through thorough planning and maintenance work, the plant is producing the same volumes in a fraction of the time— presenting a more streamlined operation that has cut down on hours with 30 – 40 % over the past five years.
“ We are in the fortunate position where the operation is starting to perform at a higher level,” says Hattingh.“ Going forward, there are a couple of plans that we have already worked on. Should the market change and the demand for our products increase over a short period, we would be ready to respond, with budgets and production plans already in place.”
According to Hattingh, this nimbleness gives Glen Douglas a competitive edge.
“ We are always looking for new markets, especially on the metallurgical side. Our biggest customer is ArcelorMittal, but we are also working with Samancor, and we are doing research on where we can capitalise on metallurgical offtake,” says Hattingh.
The maintenance, plant upgrades, and production streamlining over the past five years have not only put Glen Douglas in a solid position to respond to market demand, but with the help of the team, Hattingh says improvements have also had a positive impact on profitability.
Move towards a mega mine
The current mining fleet comprises two 80-tonne excavators— one Hitachi and one Liebherr— as well as a smaller 45-tonne excavator used as a secondary machine for loading, secondary breaking, and overburden removal. In addition, there are four 40-tonne Western Star rigid dump trucks, four Bell B40 dumpers, and three Bell B30 dumpers on site. Drilling and blasting are conducted in-house.
The mine comprises three pits: A-, B-, and C-pit. Operations started at A-pit in the 1950s. The large hole, now filled up with water, is referred to as Bass Lake, an adventure hot spot offering scuba diving and 4 × 4 driving to visitors.
In the 1980s, the metallurgical quality of the materials in A-pit decreased, and the mine expanded southwards to B- and C-pits where it is currently operating. Eighty per cent of production comes from C-pit and 20 % from B-pit.
Being close to access roads and houses, C-pit is slowly reaching its maximum mine life on the western side, with the southern border also reaching its limit. The eastern side still contains reserves, but a lot of overburden would need to be stripped to access it, says Hattingh.
“ At the moment we are keeping C-pit dry and we are predominantly using B-pit for water storage and pumping. The five to eight-year objective is to move the majority of production to B-pit as it is closer to the processing plant,” says Hattingh.“ Currently we are tidying up C-pit by adding benches. A dolerite dyke forms the border between B- and C-pits, coupled with a rock intrusion that is extracted and used as feedstock for the sub-base plant.”
Given the extensive life of mine, the three pits are likely to be one super opencast mine in the next 50 years, says Hattingh.
Producing metallurgical and aggregate material
Approximately 30 % of product mined at Glen Douglas is metallurgical, while 70 % is
20 _ QUARRY SA | March 2017