SA's century-old black wattle tannin industy

Although only a niche industry in South Africa, tannin extraction from black wattle bark for commercial applications has been practised here for over 100 years. The country’s largest tannin extraction business, NTE Company, celebrated its centenary last year, and Lloyd Phillips visited the plant to learn more about the complex processes of extracting tannin and manufacturing products from this versatile material.

- Lloyd Phillips

FAST FACTS

In the late 1880s, South Africa began exporting bundles of wet black wattle bark to animal-hide tanneries in the UK.

Tannin from black wattle bark is used in applications such as the preservation of leather and the manufacture of adhesives and flocculants.

NTE Company, based in KwaZulu-Natal, uses about 3,2t of wet black wattle bark to produce 1t of finished solid or powdered tannin extract.

The men tending the three big coal- and wood-fuelled fire chambers at NTE Company’s factory are clad from head to foot in heavy, cumbersome protective gear. There is good reason for this: they are working 2m away from 800ËšC fires that heat large boilers producing scalding water and steam. These elemental forces power no fewer than 17 separate processes used in the extraction and processing of tannin, a compound obtained from the bark of the black wattle tree (Acacia mearnsii). Tannin is invaluable for preserving and colouring leather and as an ingedient in adhesives.

NTE’s plant, based in Hermannsburg, KwaZulu-Natal (KZN), is one of two owned by the company, the other being in Iswepe, Mpumalanga. William Aherin, NTE’s industrial manager, explains that both are strategically located within South Africa’s commercial black wattle production belt stretching from the KZN Midlands north into Mpumalanga, with some production also in neighbouring eSwatini. Each factory can process up to 55 000t of raw black wattle bark during the season, which runs from September to late May.