Diamonds are naturally obtained from the earth and not every place on earth has diamond reserves. In this article, we discuss the journey of a diamond from the mines to its rough form.
Diamond Mining
The process of diamond mining can be done in three ways and they are:
Pipe Mining
In pipe mining, the miners access the diamond deposits by striking closer to the source (kimberlite pipe). Pipe mining has two forms.
Open-pit mining: In open-pit mining, the miners remove sand layers and rocks found just above the kimberlite. Once found, the ore is then blasted to break it down. A single blast is capable of breaking up to 3000 tonnes of ore.
Underground mining: In this type of mining, two tunnels, one above the other are constructed. The tunnels are connected by a funnel. When mining activities start in the first tunnel by blasting, the blasted ore reaches the second tunnel through the funnel. The loaders collect the broken down ore from the second tunnel and carry it to the surface for further processing.
Alluvial Mining
Alluvial mining is performed to mine diamonds found in alluvial deposits. In industrial alluvial mining, a wall is built to collect river water in an area, and diamonds are obtained from the gravel layer that is found beneath the layers formed by mud and clay.
Marine Mining
The diamonds are extracted from the seabed in marine mining. The modern form of marine mining involves ships that mine for diamonds deep in the sea.
How Is Ore Processed To Obtain Rough Diamonds?
Rough diamonds are obtained from ores by the following 5 steps.
Crushing
After the diamond containing ore is collected, it is sent to the primary crusher where it is reduced into smaller sizes(less than 150 mm).
Scrubbing
To get rid of the loose excess metal, the ore is scrubbed during this stage. Ore materials having sizes smaller than 1.5 mm are generally discarded.
Cyclonic Separation
In this stage, the ore is mixed with a solution of ferrosilicon and water and then fed into a cyclone that causes the separation of materials based on their density. The high-density layer of diamond-rich concentrate settles at the bottom.
Recovery
In this stage, the diamond-rich concentrate undergoes a series of processes that involve crystallographic laser fluorescence, X-ray luminescence, and magnetic susceptibility. The rough diamonds gets separated from other high-density materials.
Cleaning, Weighing, And Packing
The diamonds that are obtained in the recovery process are cleaned in an acid solution after which they are weighed, packed, and sealed into containers.