Hydrated lime with reduced resistivity and method of manufacture

Abstract

Systems and methods for generation of lime hydrate compounds and particularly highly reactive hydrated lime (HRH) with a reduced resistivity through the inclusion of a sodium compound generally in the slaking water used in generating the lime hydrate or HRH. The compound may then be used in systems which include a Electrostatic Precipitator (ESP) for SO2 mitigation without many of the associated problems in ESP performance.

1 . A method for manufacturing reduced resistivity lime hydrate, the method comprising:
 providing a particulate form of quicklime;   slaking in a hydrator said quicklime with water including a sodium compound additive to form a damp hydrated lime;   removing said damp hydrated lime from said hydrator;   flash drying said damp hydrated lime to obtain a dried lime hydrate; and   milling said dried lime hydrate to a particulate hydrated lime product;   wherein said lime hydrate has a D10 of about 0.8 microns, a D90 of about 5 microns, and a D90/D10 ratio of about 6.25.   
     
     
         2 . The method of  claim 1  wherein said sodium compound is selected from the group consisting of: sodium carbonate, sodium hydroxide, sodium bicarbonate, trona, and combinations thereof. 
     
     
         3 . The method of  claim 1  wherein said damp hydrated lime has a residual moisture of at least 5%. 
     
     
         4 . The method of  claim 3  wherein said damp hydrated lime has a residual moisture of between 5% and 35%. 
     
     
         5 . The method of  claim 3  wherein said damp hydrated lime has a residual moisture of between 10% and 25%. 
     
     
         6 . The method of  claim 1  wherein said damp hydrated lime has a residual moisture of less than 5%. 
     
     
         7 . The method of  claim 6  wherein said damp hydrated lime has a residual moisture of between 2% and 4%. 
     
     
         8 . The method of  claim 1  wherein said sodium compound additive comprises between 0.5 to 8% wt of quicklime. 
     
     
         9 . The method of  claim 8  wherein said sodium compound additive comprises between 3 to 4% wt of quicklime. 
     
     
         10 . The method of  claim 9  wherein said sodium compound additive comprises about 3.5% wt of quicklime. 
     
     
         11 . The method of  claim 1  wherein said sodium compound additive comprises between 0.4 to 12% wt of water. 
     
     
         12 . The method of  claim 11  wherein said sodium compound additive comprises between 3 to 5% wt of water. 
     
     
         13 . The method of  claim 12  wherein said sodium compound additive comprises about 4% wt of water. 
     
     
         14 . The method of  claim 1  wherein said lime hydrate has a BET surface area of at least 18 m 2 /g. 
     
     
         15 . The method of  claim 1  wherein said lime hydrate has a BET surface area of at least 30 m 2 /g. 
     
     
         17 . The method of  claim 1  wherein said lime hydrate has a D10 of less than 8 microns. 
     
     
         18 . The method of  claim 17  wherein said lime hydrate has a D50 of less than 4 microns. 
     
     
         19 . The method of  claim 1  wherein said lime hydrate has a resistivity of less than 2×10 11  ohms-cm. 
     
     
         20 . The method of  claim 1  wherein said lime hydrate has a resistivity of between 10 8  and 10 11  ohms-cm.