The ancient Orange river and south-western coastline of Namibia houses a massive diamond field” of gem quality fluvial and marine diamonds.
At SCM, the mining process begins with accreting beaches and pushing the ocean shoreline back to create minable areas.
Accretion in the Namdeb context is the increase of land by depositing sediment, usually sand or tailings. Accretion draws on two sources, namely the normal production stripping of overburden in production areas, and dedicated accretion from identified sand sources such as historic overburden dumps. This process is followed by stripping the sand overlying the deposit down to the bedrock footwall with large earth-moving equipment. The same process also creates a large defensive barrier called a seawall that serves to protect the mining activities from the Atlantic Ocean.
Accretion is important for mining at Namdeb because it opens areas for mining activities by pushing back the ocean.
The diamond bearing gravels tend to be located within terraces in the last meter or two of sand as well as the materials caught within the gullied footwall. The bulk of this material is mechanically excavated with heavy digging, dozing and rock-breaking equipment. The remaining material, which is inaccessible to the machines, is removed by means of industrial vacuum suction units called transvacs. The process of bedrock cleaning makes use of industrial vacuum suction units called transvacs. The Transvac equipment consists of a bin and suction unit. This is a people-based process that demands a reasonable degree of holistic risk management for safety and resource protection.
The collected diamondiferous material that results from the mining processes is loaded onto ridged frame trucks and hauled to the processing plant to concentrate the ore. The concentration process consists of crushing, screening, scrubbing and dense-medium separation. The concentrated diamond rich material is transported to the Red Area Complex for final recovery through x-ray luminescence technology and sorting of diamonds.
