Improving the work environment in the fluorescent lamp recycling sector by optimizing mercury elimination

The parametric study also shows that the finer the grains of glass, the higher the concentration of mercury (1.2 µg Hg/g for glass size particle >1000 µm and 152.0 µg Hg/g for glass size particle <100 µm); the crushing time required for the optimal removal of mercury from spent tubes is 24 h; on average 71% of the mercury is desorbed at a temperature of 400 °C. The effects of air flow rate, rotation speed and number of balls could not be determined due to wide variations in the results. It is recommended that recycling companies employ processes combining as heating and mixing techniques for the recovery of mercury from lamps in order to both (i) remove as much of the mercury as possible in vapor form and (ii) avoid adsorption of the mercury at new sites created during the crushing process.