Uranium In Situ Leach (Recovery) Development and Associated Environmental Issues

Michael D. Campbell¹, Henry M. Wise², and Ruffin I. Rackley^3
1 Managing Partner, M. D. Campbell and Associates, L.P. (C&A), Houston, Texas
² Exploration Manager, Texas, M. D. Campbell and Associates, L.P. (C&A), Houston, Texas
³ Director of Exploration, M. D. Campbell and Associates, L.P. (C&A), Houston, Texas

Tertiary uranium roll-front deposits of South Texas exhibit an exceptionally strong bias toward long, narrow ore bodies. Understanding these deposits is paramount in accurately determining the uranium resource available and in designing in situ leach (ISL) patterns to minimize the volume of barren sand to be included in the leach field.

As in other mining projects, ore reserves are assessed by qualified professionals on the basis of the quantity and quality of the information available about the mineralization. To assess reserves in uranium roll-front deposits where ISL is under consideration, the number and distribution of the boreholes and core samples (to evaluate the local radiometric equilibrium and the amount and type of carbon present) and the quality of the geophysical logs (elevation control, radiometric calibration, panel settings, etc.) provide the required data to produce a meaningful assessment of reserves in preparation for ISL development.

In ISL projects, the design of the well field depends on the appropriate interpretation of where in 3-dimensional space the uranium mineralization occurs. This requires not only an understanding of the geologic conditions present but also of the hydrogeologic conditions such porosity and hydraulic conductivity of the various segments of the ore zone and associated barren zones to understand the ground-water flow regime.

Uranium exploration and mining are regulated by the State of Texas. Baseline studies consisting of comprehensive characterization of geography, geology, hydrogeology, and other topics are required by the State before mining can begin. To help the permitting process proceed smoothly, a strong community relations program should be made an integral part of management’s function.

AAPG Search and Discover Article #90069©2007 GCAGS 57th Annual Convention, Corpus Christi, Texas