Study of the Thermodynamics of the Hg(2+) -I -H20 System and the Recovery of Mercury from Mercury-Bearing Gases

摘要

In view of the characteristic of iodine to form stable complexes with mercury, mercury-bearing sulphur dioxide gases are scrubbed by a potassium iodide solution in a packed column. More than 99 percent of the mercury is recoverable and an acceptable sulphuric acid can be produced. The thermodynamics of the Hg(2+) -I(1-) -H2O system and the effects of iodine ion concentration, acidity and mercury concentration in the absorbent solution on the efficiency of mercury removal are examined. The kinetics of the process are studied and the relationship between mercury concentration in the tail gas and the gas-liquid contact duration time is obtained. It has been shown by experiments that electrolysis is the best method for recovering mercury from the absorbent solution.