Improved rare mercury recovery from fluorescent lamp wastes through simultaneous leaching and heating

Abstract

Mercury is one of the most dangerous environmental pollutants due to its stability in the environment and bioaccumulation in the food chain. Regarding the adverse effects of mercury on human health and environment, huge efforts have been made throughout the world to reduce its undesirable impacts. Mercury is one of the main components of the low-consumption and uorescent lamps. Recovery of Hgcontaining uorescent lamps is of crucial signi cance in the developed countries. The glass parts of the used uorescent lamps are among the dangerous wastes whose Hg content should be reduced to the lowest possible level according to the global standards. In this research, a de nite amount of glass parts of the uorescent lamps was washed with a de nite volume of deionized water to separate and minimize their Hg content. To enhance the leaching e ciency and extract the mercury content, the mixture was stirred. Then parameters such as the ratio of glass to deionized water (S/L), stirring time, temperature, and pH were changed to achieve the highest Hg extraction. The highest Hg extraction (98%) was achieved at S/L = 0.1, stirring time of 12 h, temperature of 60℃, pH = 1 (using a combination of HCl and phosphoric acid 5% with the ratio of 1:4). The results con rmed a decline in the Hg content of the glass by decrementing pH in an acidic environment. The resultant glass wastes can be classi ed as nondangerous wastes.