Effect of Calcium Addition on Formation of Particulate Mercury in Coal Combustion Process

Combustion experiments on two types of coal with additions of CaO and CaCl₂ were conducted in a high-temperature entrained-flow pulverized-coal reactor, during which ash samples under various combustion conditions were collected, so as to measure the mass fraction of Hg and perform EDS and XRD analysis on the fly ash. Results show that the addition of CaO may promote the formation of Hg_p, but its promotion effect is weaker than CaCl₂. Maximum ratio of Hg_p shall be found in flue gas at a CaCl₂ addition ratio of 3%, when the mass fraction of Cl in fly ash reaches the highest in the total inlet of Cl.