Open AccessALUMINUM REMOVAL FROM HANFORD WASTE BY LITHIUM HYDROTALCITE PRECIPITATION - LABORATORY SCALE VALIDATION ON WASTE SIMULANTS TEST REPORT
Author(s) -
T.L. Sams,
K.J. Hagerty
Publication year - 2011
Language(s) - English
Resource type - Reports
DOI - 10.2172/1010336
Subject(s) - hydrotalcite , sodium hydroxide , leachate , hydroxide , sodium aluminate , lithium (medication) , chemistry , materials science , precipitation , nuclear chemistry , waste management , sodium , inorganic chemistry , metallurgy , aluminium , environmental chemistry , organic chemistry , catalysis , medicine , physics , meteorology , engineering , endocrinology
To reduce the additional sodium hydroxide and ease processing of aluminum bearing sludge, the lithium hydrotalcite (LiHT) process has been invented by AREV A and demonstrated on a laboratory scale to remove alumina and regenerate/recycle sodium hydroxide prior to processing in the WTP. The method uses lithium hydroxide (LiOH) to precipitate sodium aluminate (NaAI(OH){sub 4}) as lithium hydrotalcite (Li{sub 2}CO{sub 3}.4Al(OH){sub 3}.3H{sub 2}O) while generating sodium hydroxide (NaOH). In addition, phosphate substitutes in the reaction to a high degree, also as a filterable solid. The sodium hydroxide enriched leachate is depleted in aluminum and phosphate, and is recycled to double-shell tanks (DSTs) to leach aluminum bearing sludges. This method eliminates importing sodium hydroxide to leach alumina sludge and eliminates a large fraction of the total sludge mass to be treated by the WTP. Plugging of process equipment is reduced by removal of both aluminum and phosphate in the tank wastes. Laboratory tests were conducted to verify the efficacy of the process and confirm the results of previous tests. These tests used both single-shell tank (SST) and DST simulants