Mining and Resource Replenishment
Due to the Tormin mineralised beach sands having minimal or no overburden or vegetation (high tide mark is generally to the cliff face), and the close proximity of the mineralised beach sands to the processing plant, Mineral Commodites is able to process mineral sands with minimum disturbance to the existing environment.
Unlike dredge mining, which involves the recovery of the ore from a void filled with groundwater, or inland dry mining, which involves the initial removal of vegetation, topsoil and overburden, MRC’s Tormin mine use the dry mining technique on unvegetated beach sands, and as such has a much less significant impact on the environment.
Once the beach ore is transported to the processing plant, it is screened (to remove oversize material), slurried with sea-water and then passed through concentration process to remove, as tailings, the non-valuable beach sand materials such as silica, and then through a a minerals separation process to separate the valuable heavy minerals into saleable products.
This process negates the need to introduce either heat or chemicals to process or refine the raw material, and as such, MRC has very little impact to the environment through the processing of our its mineral sands.
The concentrating process involves the screened ore being passed through a heavy mineral concentration plant. This process yields a substance which is referred to as heavy mineral concentrate (HMC). This concentrated material is separated from the lighter tailings (waste material) using gravity spirals.
The use of gravity, not chemicals or other harmful means to separate the sand of value from the non-valuable sand means that when we discuss “waste material” we are talking about untreated, wet sand which was dug up from the beach only hours previously. These tailings are either returned by pumping directly to the mined beach, or placed in drying ponds from which water may be recovered for re-use.
The minerals separation process again neither uses heat or chemicals to both separate and beneficiate the valuable heavy minerals into saleable products.
The saleable products are either then bagged in secure 2 tonne bulk bags, transported by road and shipped in containers via the Cape Town port, or otherwise stockpiled at the plant site, transported by road and shipped in bulk from the Saldana Port.
Mining Rehabilitation and Resource Replenishment
The mined beach sand naturally replenishes itself due to the effect of normal tidal and storm movements depositing offshore sands onto the beach.
Of the 4.5 million tonnes of beach sand mined up to December 2016, the replacement of processed beach sand tailings and the effect of tidal and storm movement depositing onto the beach offshore sands has ensured full replenishment of the sand that has been extracted. The replaced sand contains valuable mineralisation and has at times allowed re-mining of the same mining area up to ten times.
This replenishment process is quite unique in the global mining industry, which ordinarily creates a mined void after single resource extraction, and usually requires the management of chemicals within tailing and mined void back-filling, topsoil replacement and revegetation.