Abstract:

As solid hazardous waste,the leaching solution of electrolytic aluminum overhaul slag contains a large amount of fluoride ions,which should be determined for treatment and disposal.At present,the method for determining the fluoride ion content in the leaching solution of overhaul residues is generally adopted GB 5086.1—1997,namely,《Solid Waste Leaching Toxicity Leaching Method-Turnover Method》,which is time-consuming and low efficiency.In response to this problem,a method to quickly determine the fluoride ion content in the overhaul slag leachate was proposed.Through the enhancement of the solid-liquid interface mass transfer process to promote the solid-liquid transfer of soluble fluoride in the overhaul slag,thereby the detection efficiency was greatly improved and the time was reduced from 18 h to 0.5 h.The experimental results showed that the leaching quality of fluoride ion in the overhaul slag was in the range of 9 000 to 70 000 mg/kg,the relative standard deviation was less than 5.0%,and the recovery rate of standard addition was between 96.35% to 108.8%,indicating that the rapid determination method was stable and high accuracy,which was expected to become a standard method for determining the fluoride ion content in the leaching solution of overhaul residue.

Key words: overhaul residue, leaching solution, fluoride ion, detection method