Flue gas scrubbing

1. A method of collecting mercury from a flue gas comprising:

injecting a mercury sorbent material into a flue duct carrying the flue gas to provide an injection concentration, the mercury sorbent material made by exothermically shearing a smectite clay containing an exchangeable cation with a copper salt and a sulfur source; and providing an enthalpically driven ion pairing of the clay exchangeable cation with the copper salt; and wherein the mercury sorbent material is substantially free of a diffraction peak at 2.73±0.01 Å;

reacting the mercury sorbent material with mercury in the flue gas to form a mercury-sorbed material and thereby reducing the concentration of mercury in the flue gas;

injecting lime into the flue duct at a location such that the mercury sorbent material and the lime mix in the flue duct;

reacting the lime with SO 2 , SO 3 , and/or HCl in the flue gas to form a reaction product selected from the group consisting of a calcium sulfate, a calcium chloride, and a mixture thereof; and

collecting a byproduct mixture that comprises the mercury-sorbed material, and any unreacted mercury sorbent material.

2. The method of claim 1 , wherein the byproduct mixture includes unreacted lime.

3. The method of claim 1 , wherein the byproduct mixture includes fly ash.

4. The method of claim 1 , wherein the injection concentration of the mercury sorbent material is in a range of about 1 to about 20 lbs/MMacf of flue gas.

5. The method of claim 1 , wherein an injection rate of lime is less than about 10,000 lbs/hr.

6. The method of claim 1 , wherein the mercury sorbent material and the lime are synergistic.

7. A method of collecting mercury from a flue gas comprising:

admixing a mercury sorbent material and lime to form a flue gas scrubbing composition, the mercury sorbent material made by exothermically shearing a smectite clay containing an exchangeable cation with a copper salt and a sulfur source; and providing an enthalpically driven ion pairing of the clay exchangeable cation with the copper salt; and wherein the mercury sorbent material is substantially free of a diffraction peak at 2.73±0.01 Å; then

injecting the flue gas scrubbing composition into a flue duct containing a flue gas, wherein the flue gas scrubbing composition reacts with mercury and SO 2 , SO 3 , and/or HCl in the flue gas, forming a mercury-sorbed material and thereby reducing the concentration of mercury in the flue gas; and

collecting a mixture that includes the mercury-sorbed material and any unreacted flue gas scrubbing composition.

8. The method of claim 7 , wherein a flue gas scrubbing composition injection rate comprises a lime injection rate of less than about 10,000 lbs/hr and a mercury sorbent material injection concentration in a range of about 1 to about 20 lbs/MMacf.

9. The method of claim 7 , wherein the mercury sorbent material and the lime are admixed in a mass ratio sufficient to provide a predetermined lime injection rate and mercury sorbent material injection concentration based on a predetermined flue gas flow rate.

10. The method of claim 7 further comprising determining the flue gas flow rate;

determining the mercury and sulfur concentrations in the flue gas;

determining a mercury sorbent material injection concentration; and

determining a lime injection rate;

wherein the mercury sorbent material and lime are admixed in a ratio sufficient to provide the lime injection rate, the mercury sorbent material injection concentration, and at least an 80% mercury removal.

11. The method of claim 7 , wherein the mercury sorbent material and the lime are synergistic.

12. A method of entombing mercury comprising:

mixing a byproduct mixture that comprises the mercury-sorbed material formed by the method of claim 1 with water to form a freshly mixed concrete, the mercury-sorbed material made by reacting a mercury sorbent material with a mercury containing flue gas; and

casting the freshly mixed concrete into a form.

13. The method of claim 12 further comprising mixing the byproduct mixture with Portland Cement.

14. The method of claim 12 , wherein the byproduct mixture comprises at least one material selected from the group consisting of a mercury sorbent material, a lime, a calcium sulfate, a fly ash, and a mixture thereof.

15. The method of claim 14 , wherein the byproduct mixture comprises the mercury-sorbed material, the mercury sorbent material, a lime, a calcium sulfate, and a fly ash.

16. A flue gas scrubbing composition consisting essentially of:

a mercury sorbent material that is substantially free of a clay/covellite composite as determined by powder X-ray diffraction, the powder X-ray diffraction pattern being substantially free of a peak at 2.73 ±0.01 Å, and made by shearing a mixture of a silicate, a copper ion source, a sulfide ion source, and water; and

lime that comprises calcium oxide and/or calcium hydroxide.

17. The flue gas scrubbing composition of claim 16 , wherein a mercury absorptivity of the flue gas scrubbing composition is greater than 70% of a mercury absorptivity of the mercury sorbent material in the absence of the lime.

18. The flue gas scrubbing composition of claim 16 further comprising a ratio of the mercury sorbent material and lime sufficient to provide a predetermined lime injection rate and mercury sorbent material injection concentration based on a predetermined flue gas flow rate.