Global commodities trader IMR Resources is set to expand its Kgatelopele Lime (KP Lime) mine, in the Northern Cape, with a second openpit operation that is expected to be built within the next two years in close proximity to the currently in-use Bowden pit.

Previously owned by construction materials company PPC, the KP Lime mine was acquired by IMR in April 2021 and is unique in being the largest supplier of metallurgical-grade lime in South Africa, as well as supplying reactive lime, hard burnt lime, hydrated lime, burnt dolomitic lime and raw limestone.

In the Southern African region, this type and grade of limestone deposit is only found at outcrops of the same deposit at Lime Acres and Postmasburg, while the next deposit of similar grade and quality is found in Ndola, in Zambia, says KP Lime sales and marketing chief Mpho Lebeta.

The mine has extensive assets on site, including a nearby mining town – Lime Acres, which is shared with employees of the nearby Finsch mine of Petra Diamonds – processing facilities for crushing and screening, two pre-heater kilns, a laboratory and a rail siding and truck loading depot.

Located in a remote region about 160 km from Kimberley, the mine first opened in 1954, with the Bowden pit still having about 12 to 14 years of life in its reserves.

The new pit will have a life of at least 60 years, says KP Lime operations GM Deon Janssen.

The mine currently employs about 250 personnel, with contractors being used for drilling operations and security services.

Gabora drilling conducts blast-hole drilling about once a week using two drills on site, following which an in-house basting team conducts blasting in the pit, which reaches depths of about 100 m.

Primary mining is undertaken using wheel loaders, a few large shovels and a fleet of 150 t rigid diesel-electric haul trucks to excavate between 4.5-million and 5-million tonnes of overburden, limestone and dolomite a year.

Since KP Lime took ownership of the mine, he says it has been performing well, having only encountered challenges such as increasing diesel, explosives and coal prices, which have driven up operating costs.

“We have managed to work around that and we have managed to contain the costs as much as possible,” says Janssen.

The limestone products from the mine are used in processes in key local industries such as steel and alloy production, as well as the production of gold, uranium and copper, while also having applications in the production of non-ferrous metals, sugar refining, water treatment and in the flue gas desulphurisation process of coal-fired power stations.

The past year has proved challenging in terms of market conditions, but Lebeta says the company has been resilient, with the water purification industry and gold sector offtakers being the backbone of the business.

He says this year is looking much better in terms of market performance, with KP Lime developing “creative ways” to approach the market and attract new clients.

Janssen says quality assurance is a top priority for KP Lime, with the bulk of customers requiring lime products of about 95% calcium carbonate.

“If you are using limestone for the pyrometallurgical, hydrometallurgical and water treatment sectors, you need to be averaging above 90% calcium oxide content,” says Lebeta.

To attain this specification, KP Lime blends ore from different benches of the mine to reach the required blend. To ensure consistency and quality, a sampling plant and laboratory is situated on site to analyse ore and final product.

Product from the mine is available through a collect and deliver service offered by KP Lime. Alternatively, clients can provide their own transport.

The company also has a depot at the Highveld Industrial Park in Mpumalanga – home to the former Evraz Highveld steel mill. The depot has the appropriate infrastructure on site as it used to be used for storing lime for use by the expansive mill. This depot provides flexibility, by enabling quicker delivery to clients in Gauteng and Mpumalanga.

Despite having a substantial rail siding at the mine, currently about 80% of product is shipped using trucks, with the remaining 20% transported by rail. The rail siding has capacity to accommodate as many as 300 wagons, but inefficiencies by Transnet Freight Rail have resulted in this mode of transport being curtailed as trains cannot be as easily made available as in the past.

KP Lime also supplies customers in Southern Africa, such as those in Namibia, Botswana and Zimbabwe, as well as in the Democratic Republic of Congo and Reunion Island, the latter for water treatment and flue gas desulphurisation.

KP Lime has a rotary kiln capacity of about 1 000 t a day and a storage capacity of 7 100 t in on-site silos.

Lebeta says KP Lime offers security of supply, with its mining capacity currently exceeding market demand.