Additives for mercury oxidation in coal-fired power plants

A flue gas treatment method, comprising:

• (a) providing a coal feed, the coal feed having a Loss on Ignition (“LOI”) of at least about 10% and comprising mercury, alkali, and iron, wherein an iron content of the coal feed is less than about 10 wt. % (dry basis of the ash) as Fe2O3, the alkali content of the coal feed is at least about 20 wt. % (dry basis of the ash) alkali, and wherein the coal feed comprises no more than about 500 ppm halogens;
• (b) contacting the coal feed, prior to combustion, with an additive, the additive comprising a transition metal and a halogen, wherein the additive promotes oxidation of elemental mercury wherein the additive comprises no more than about 1 wt. % carbon and no more than about 0.5 wt. % (dry basis) sulfur;
• (c) combusting, by a wet bottom boiler, the coal feed to form a flue gas comprising elemental mercury derived from the mercury in the coal feed and fly ash;
• and
• (d) collecting the oxidized mercury and fly ash to provide a treated flue gas, wherein:
• the additive further comprises a mineralizer;
• the mineralizer is zinc oxide;
• and
• the additive comprises at least about 1 wt. % (dry basis) mineralizer.