Tailing Treatment Techniques for Uranium Mill Waste: A Review of Existing Information.

摘要

In this study, three general amelioration methods were identified: neutralization, fixation and specific constituent removal. At present, neutralization processes appear to be best suited for treating uranium mill tailings because they can, at a reasonable cost, limit the solution concentration of many contaminants, thus reducing the potential for ground-water contamination. However, the effectiveness of the process depends on the reagent used as well as the waste being treated. Of the six reagents studied (lime, limestone, caustic soda, soda ash, combined limestone/lime and combined alumina/lime/soda), a combined treatment of limestone and lime seems best, especially for tailings containing ferric iron as the limestone economically buffers the solution acidity while the lime takes the pH to 8.0, an optimum level for heavy metal removal. For those tailings containing ferrous iron, lime alone works best. In general, the costs for the lime/limestone or lime processes range from $0.20 to $1.00 per 1000 gallons of treated water, excluding capital equipment costs.