February 8, 2022

Everything You Need to Know about How Uranium Is Mined

There are a lot of ways on how uranium resources are mined. They are underground mining,  open pit mining, and in situ recovery mining. 

Let’s get to know each of these mining processes of uranium one by one.

Underground Mining

Underground mining is done by drilling and blasting. Mining companies dig out the desired uranium ore. Through this process, a higher concentration of uranium is taken as it goes much deeper compared to open pit mining. Once the ore is drilled and blasted, the resulting debris are taken out to the surface and delivered for milling.

Pros

  • less waste rock piles
  • less land disturbance and surface footprint
  • can use advanced mining technology (robotic mining) and safety monitoring procedures (ventilation and monitoring badges)

Cons

  • higher cost of extraction
  • health hazards to miners (poor ventilation) due to diesel fumes, radon, and dust
  • potential risks on local aquifers and expensive remediation

Open Pit Mining

Open pit mining is a surface mining technique that is done by removing the top soil and rocks underneath to excavate the uranium ore. The debris is recovered and transported to the milling facilities.

This type of mining is usually used if the uranium ores are located above shallow deposits. This form of mining is used for a high grade ore.

Pros

  • better ventilation
  • less expensive than underground mining
  • strict safety, environmental and health guidelines

Cons

  • more waste rock piles
  • more land disturbance and huge surface footprint
  • expensive groundwater restoration
  • time-consuming and expensive remediation

In-Situ Recovery Mining

In-situ recovery (ISR) mining is done underground and close to the uranium source. This method dissolves the uranium by injecting water into the ground and pumping the solution to the surface. It is commonly used when the uranium is located close to the surface.

ISR is more environmentally friendly than open pit mining. In the US, IRS involves:

  • pumping water and gaseous oxygen, sometimes baking soda as oxidant to make it way faster for uranium resources to go into the solution.
  • the solution is pumped to the surface, then the uranium is recovered for further processing.
  • the solution is pumped to the surface and pumped into holding tanks or ponds.
  • a holding pond is used to store the uranium solution.
  • the solution is then pumped to settling ponds.
  • the uranium is settled or trapped in the settling ponds as it is heavier than water.
  • once the sewage is bright yellow in color, the solution is pumped to the recovery wells or to the uranium plant for extraction.
  • the remaining solution is cleaned and recycled to re-use in the next batch of in-situ recovery wells.
  • this whole procedure is intended not to harm the environment while getting the uranium ore.

Pros

  • little waste rock piles
  • less land disturbance and surface footprint
  • less potential risks on local aquifers
  • quick and less expensive
  • less expensive on remediation
  • less radiation to miners

Cons

  • problems with groundwater
  • possible ground subsidence
  • waters need pumping and monitoring
  • water waste disposal

Milling

Once the ore is mined, it’s transported and then it will be processed to extract uranium. In the milling process, the ore is crushed and ground into fine powder for further processing.

Milling is done so that the uranium is separated from the ore. U3O8 or uranium are minerals that can be extracted. The other metals are usually iron, copper, mercury and vanadium. The finely ground ore is placed in the process plant where it’s treated with acid and the slurry is filtered to separate the metals. The uranium is purified by ion exchange. In this process, the uranium is stripped of other metals and then the uranium is put into a solution.

When the uranium is stripped, it becomes uranium oxide or yellow cake. At this phase, the uranium is ready to be used as nuclear fuel.

Conclusion

So far, there are a lot of things to know about uranium mining and the different methods of uranium extraction. There are advantages and disadvantages to every method and each has its own impact on the environment. The way uranium is mined depends on the type and location of the ore. High-quality ores that need to be dug up, and low-grade ores that can be mined..

enCore Energy Corp. is a domestic uranium developer focused on becoming a leading in-situ recovery uranium producer. Let us provide you with great opportunities for mining uranium using the IRS. Contact us today for more information.