Abstract:
<p align="justify"> The spent pot liner (SPL) is a solid waste generated in the process of aluminum production and is considered hazardous because of its fluoride and cyanide content. The purpose of this study was to analyze the SPL fraction with low cyanide coming from Aluminio Brasileiro S.A. (ALBRAS). For all the pots studied the pH of the spent pot liner (SPL) was very high and ranged from 10 to 11.80. The total fluoride content determined at high pH varied from 5.13 to 11.41 %, while the total fluoride determined in leached fluid at pH 5.0 had low values that ranged from 0.26 to 3.46 %, indicating the low solubility of waste fluorides at low pH values. With leaching fluid above pH 12, the total fluoride content varied from 6.45 to 9.39 %. The experimental results indicate that the Brazilian Standard NBR 10.004, based on leaching at pH 5.0 is not adequate for the classification of hazardous waste, since it underestimates fluoride content. </p>