Uranium is a naturally occurring element that is used primarily for making electricity. Uranium can be extracted from the ground in three ways. They are open pit, underground, and in-situ leach (ISL). The method and processing parameter depends on multiple factors. They are primarily associated with the geological and geotechnical characteristics of the uranium deposit including its mineralogy and rock type, as well several other factors.
Uranium mining companies use open pit or strip mining if the uranium ore is near the surface. It involves moving and storing waste rock or overburden near the open pit. Once the uranium is exposed, then a series of benches or steps are cut into it in order to make removal easier. Depending on the size of the mine, there may be roads cut into the sides in order for the haulers to navigate the area. In addition, pumps may be used to remove water from the pit. It is less expensive and provides better ventilation than other types of mines.
Another type of uranium mining that is often used is that which is done underground. It is used in order to get to uranium that is too deep to get at from open-pit. The uranium is drilled and then blasted in order to create debris which is then transported to the surface. It is then moved to a mill. This type of mining has a smaller surface footprint and less waste rock than open pit mining. Recent technological advances have made underground mining safer in recent years. However, it is more expensive.
When it comes to both underground and open pit mining, uranium production generally only have a small percentage of uranium in them. It needs to be removed from the rock and concentrated. This is done through a milling process that includes crushing and pulverizing the rock into fine fragments and adding water in order to create a slurry. It is then mixed with sulfuric acid or an alkaline solution that can recover an average of 95 percent of the uranium from the host rock. It is precipitated as what is commonly referred to a yellowcake. However, it is still not the purest form and needs to be sent to another plant to be enriched. The rest of the rock slurry is then pumped into a tailings dam. The tailings are then exposed to the surface and heavy metals are released into the environment.
In-situ Leach is the preferred extraction method for uranium. This is due in part to the fact that it is far cheaper to get the deposits out of the ground and it is also considered more environmentally friendly than that of both traditional underground and open pit mines. In addition, this type of mining leaves behind a small surface footprint and very little waste rock. It is also an inexpensive startup and less expensive to remediate than traditional mining and milling operations. Moreover, it also makes it so that there is less radiation exposure for the workers, as well as a smaller and higher trained workforce.