Minerals – Carbonates

The Group’s carbonates operation in Port Shepstone, KwaZulu-Natal, produces a range of products derived from calcitic and dolomitic limestone, which serve the agricultural, glass, paint, paper, plastics and chemical industries.

The operation mines a deposit of white calcitic and dolomitic limestone which then goes through various processes of quarrying, crushing, screening, milling and beneficiation through flotation and fine milling (micronising) to produce the end product.


Floated products are typically used as a filler in the paper, paint and plastic industries. Floated dry calcium carbonate products offer qualities of brilliant whiteness, mineralogical purity and controlled particle size. The range includes a floated calcium carbonate slurry for use in paper coating applications. Stearic acid-coated calcium carbonate powder has excellent dispersion properties for paint and plastics.

Speciality carbonates are used as a filler or fluxing agent in the glass and chemical industries. Unfloated products are used in chemical processing and in manufacturing explosives for the mining industry as well as in agriculture.


The limestone extracted at Idwala Lime’s Port Shepstone operation is sourced from a white marble delta, which was
once a glacier. Here it is milled and floated, or added to water with a flotation agent, to remove impurities such as chard, silica, magnesium and iron. The impurities bond to the agent and are floated off the surface, leaving the pure product below.
Fine quality, calcium carbonate lends its pure white colour as
a filler for paint, plastics, paper, rubber, tiles, adhesives, resins and gypsum.