Richness from the sand

In front of me lies a massive sand mound, next to it my bakkie looks like a dinky toy. As far as the eye can see the sand mound lies stretched out, many stories high. Here, in the middle of nowhere, power lines, buildings and a conveyor belt kilometers long. We are in Brand se Baai (Bay) on our way to the Olifants River's mouth. And this sand mine belongs to Namakwa Sands.

Sea sand is formed when rocks and hard shells coming from marine organisms, are broken down to small particles by wind, waves and weathering. Technically spoken sand grains are anything between 0,2 and 2mm in size. Anything smaller is called silt, anything bigger is called gravel. The white sand of the West Coast has a high shell content and originates from pale sandstone.

Although most of the rock making minerals are present in sand, quarts is by far the most common, because it is abundant in rocks, is comparatively hard and it has practically no cleavage planes so it is not readily worn down to a fine state.  Moreover, it is nearly insoluble in water and does not decompose.  Quarts consist of silicon dioxide or silica.  Lime or calcium carbonate  and feldspar are often common in sea sand.  All sands contain small quantities of “heavy” rock-forming minerals such as garnets, tourmaline, zircon, tutile, topaz, pyroxenes, amphiboles and iron ores.

Namakwa Sands mine the heavy sands to extract and separate the minerals ilmenite, rutile and zircon at Koekenaap, 60km from the mine. The products are transported by rail to the smelter near Saldanha Bay.  Namakwa Sands operates two furnaces where ilmenite is melted to produce titanium slag and pig iron.  Rutile is used as the base for the manufacture of paints, coatings and plastics, and is also converted to titanium metal, which is found in jet aircraft, spectacle frames, artificial limbs and other modern applications.  Zircon is used in the ceramic industry for the white glazing of wall tiles and bathroom fittings.  It is also used in the construction, steel, glass abrasive and metal industries as a refractory – a substance that is able to resist high temperatures and corrosion.

South Africa is second only to Australia as a world leader in the mineral sands industry, accounting for about 23% of the world`s titanium ore.

The Namakwa Sands operation started in 1994 and is one of the largest mineral sand operations in the world. The Namakwa Sands mine is located in a sensitive area in terms of biodiversity. The area is also very arid, making re-vegetation difficult. That said, Namakwa Sands has been rehabilitating mined land since the inception of the mine 23 years ago. The mine has developed procedures for various aspects of the rehabilitation and re-vegetation process.

To minimise the loss or contamination of topsoil during stripping, stockpiling, handling and placement on rehabilitated areas and to retain or improve soil fertility and minimise soil compaction, soil stripping has been guided by the pre-mining soil map and the Namakwa Sands procedure for topsoil removal. Stripped soil has been placed on available rehabilitated re-profiled areas wherever possible. This is to minimise loss of viability in stripped seeds and mycorrhizae within the soils.  Stockpiles had not been located within 100 m of any recognized water course.  If topsoil stockpiles were not to be used within two months of stripping, the topsoil stockpile was protected from wind erosion through the erection of shade cloth windbreaks. The topsoil layers were placed at the top of the profile to improve fertility in the upper soil layers and to retain seed stocks in the rehabilitated environment. This is particularly relevant where direct placement occurs. Direct soil placement is the preferred method of soil handling for technical and economic reasons.

Unfortunately, the monitoring of performance of rehabilitated land has not been well documented, making it difficult to evaluate the performance of different methods of rehabilitation and re-vegetation that have been applied since inception of the mine. This does not detract from the effort and investment that the mine has made regarding the re-vegetation of disturbed areas.