Lignite Part II : A Novel Material for Low-Cost Removal and Disposal of Heavy Metals and Radionuclides from Waste Water

Preliminary experiments were conducted to assess the efficiency of the MERSAD concept for vitrifying and stabilizing uranium which was loaded onto a Western Kentucky lignite using uranyl nitrate. 443 g of lignite were added to 10 liters of a 1540 ppm solution of uranium, as uranyl nitrate, and the mixture was stirred for 10 minutes prior to filtration. The amount of uranium in the filtrate was found to be 490 ppm, giving an overall lignite cation exchange capacity of 0.2 meq/g for the uranyl cation. The uranium loaded lignite was then pyrolyzed at 1600 °F under nitrogen (uranium yield of 104 ± 5%) and the resulting char was subjected to treatment in the AGCOMM bench-scale reactor. Total mass and uranium balances were calculated for the products from the fluid bed and cyclone. The uranium concentrations were determined by gamma-ray spectroscopy using a NaI(Tl) wellcounter. The results, showed in Table 3, are expressed as specific activity (counts per second per gram of sample), which is directly proportional to uranium concentrations. Leach tests with deionized water and TCLP extraction fluid #2 (dilute acetic acid) Trace elements in coal