Solution Mining for Uranium

Activity Source: Minerals Education Coalition

 

Grade Levels: 7-12

Background

Nuclear energy is used around the world to generate electrical power in a way that does not produce greenhouse gases. Its use is predicted to grow in the coming years. This will increase the demand for uranium, which is mined for medical, industrial, and defense purposes, in addition to producing nuclear energy. Although it is mined in several ways, most uranium in the U.S. is mined by solution mining. This activity models the primary steps of solution mining for uranium.

Materials

  • Large container like a plastic tub or aquarium
  • Washed sand (moistened)
  • Clay (very fine sediment, moistened)
  • Light-colored soil, sand, or other sediment
  • Salt (NaCl) with coarse crystals (deicing salt)
  • Water
  • Pipettes or small syringes
  • Large and small diameter straws
  • Heat-safe petri dishes
  • Heat source (e.g., hot plate)

SAFETY NOTE: This activity uses a heat source and should be conducted with adult supervision.

Procedure

  1. Mix 1 part salt crystals into 5 parts of sand.
  2. In a large bin, make 3 2-inch thick layers: clay (brown layers in diagram), sand/salt (yellow layer). The salt/sand layer represents an “orebody” containing soluble uranium minerals.
  3. Fill the rest of the bin with a light-colored sand or other sediments.
  4. Insert large diameter straws on a 2-inch-square grid pattern through the top layers and into the orebody, simulating drilling wells into a uranium deposit.
    • Leave the large straws in place to hold the holes open.
    • Use a smaller straw to remove most of the sediment from each drill hole.
  5. Label alternate rows of wells “injection” and “production.”
    • Using a pipette, slowly add water to the injection holes, allowing the salt to dissolve. In uranium mining, a carbonated or mildly acidic solvent is used to dissolve uranium minerals.
    • After allowing time for the solution to migrate, use the pipette to carefully extract brine from the production holes. This simulates uranium-bearing solution being pumped to the surface.
  6. Transfer the brine to shallow dishes on a heat source to evaporate the water and leave the dried salt behind. Likewise, uranium-bearing solution must be processed to extract the uranium.

Analysis

  1. Discuss the pros and cons of solution mining versus surface or underground mining (e.g., ecosystem impacts, water quality).
  2. Study where uranium is mined in the U.S..

Further Steps

Access additional activities in MEC’s “Rockin’ Energy: Uncovering the Power of Minerals and Rocks” unit.

Use the teacher search tool for correlations to national and state standards.

NGSS Connections

  • SEP: Developing and Using Models
  • DCI: ESS2.A: Earth’s Materials; ESS3.B: Natural Resources
  • CCC: Influence of Science, Engineering, and Technology on Society and the Natural World

SDG Connections