Minerals – Lime

Bud’s lime operation in Danielskuil, Northern Cape, predominantly produces calcitic burnt lime and limestone, which serves the mining, chemicals, metallurgical, agricultural, water, road building and environment-related industries.

Lime is used, for example, to raise the pH level to allow for the addition of cyanide during gold processing, and as a flux and purifying agent in pyrometallurgical applications. It acts as a sorbent in flue gas desulphurisation, which removes acidic gases emitted by coal based power generators, and is critically used in the treatment of acid mine water.

Limestone also plays an important role as a calcium source for agricultural fertilisers and animal feeds, and as an aggregate in concrete and cement bricks.

PRODUCT OVERVIEW

LIMESTONE
Includes agricultural lime, calcite and calcium carbonate.

UNSLAKED LIME
Also known as burnt lime, quick lime or calcium oxide.

SLAKED LIME
Also known as hydrated lime or calcium hydroxide.

OPERATIONS

IDWALA LIME
Idwala Lime’s operations at Danielskuil in the Northern Cape focus on the extraction and crushing of high-grade calcium carbonate, or limestone.

This material is screened and burnt in a kiln at temperatures of 1200 degrees Celsius to create calcium oxide or unslaked lime, which is milled for a variety of chemical processes. These include pH control in platinum and uranium processing and in the treatment of water and effluent. In road building it is used to stabilise the soil, while it also plays a role in gold extraction and flue gas desulphurisation.

Lump lime is also sent from Danielskuil to Idwala Lime in Vereeniging, where it is milled and water is added to create a chemical reaction that forms calcium hydroxide, or slaked lime.