Uranium Mining Three Main Types 1. Strip Mining 2. Tunnel Mining 3. In-Situ Mining Texas: In-Situ Mining
What is In-Situ Mining? 1. A basic or acidic leaching solution is injected into the ground. 2. The solution flows through the rock and dissolves the uranium (plus a whole bunch of other heavy metals including releasing Radon gas). 3. The dissolved metals are then brought to the surface through recovery wells.
Scheme of Normal ISL Operation
Wellfield in Wyoming
Conventional vs. In-Situ mining In-situ mining: In-situ mining: Uses leach solution to recover ore Ore in place (no rock movement) Little or no surface disturbance No tailing or any significant waste Major environmental and closure advantages Substantial reduction in water use Cost-effective Source of information: Water Management Consultants
Leach Solution Alkaline leaching – typically ammonium carbonate [(NH 4 ) 2 CO 3 ] or sodium bicarbonate, Alkaline leaching – typically ammonium carbonate [(NH 4 ) 2 CO 3 ] or sodium bicarbonate, Acid leaching (mostly for uranium silicate) – typically weak sulfuric acid [H 2 SO 4 ] enriched with air sparging or ferric iron Acid leaching (mostly for uranium silicate) – typically weak sulfuric acid [H 2 SO 4 ] enriched with air sparging or ferric iron Source of information: Water Management Consultants Source of information: Water Management Consultants
Problems with Uranium In-Situ Mining High probability of uncontrolled and irreversible groundwater contamination. Emission of Radon gas into the atmosphere. Contaminated waste from dissolved heavy metals.
Uranium mining in Texas
Nuclear Power Plants in US
Comanche Peak Power Plant, Glen Rose, TX Source: P. A. Scholle & D. S. Ulmer-Scholle, 1997, SEPM Photo CD-14, Environmental Sciences 5, SEPM, Tulsa, OK.
Cost of Nuclear vs. Coal After taking into consideration fuel, maintenance, taxes, fees, capital, decommissioning, etc. : After taking into consideration fuel, maintenance, taxes, fees, capital, decommissioning, etc. : Coal = 29.1Mw-hr Coal = 29.1Mw-hr Nuclear = 30.0Mw-hr Nuclear = 30.0Mw-hr Nuclear is slightly more expensive than coal Nuclear is slightly more expensive than coal