Study of the Potential for Recovering Unreacted Lime from Limestone Modified Flyash by Agglomerate

摘要

The feasibility was studied of recovering the unreacted lime from limestone modified flyash by froth flotation of 200 x 325 mesh fractions. Grades of lime recovered were as high as 80 percent; 47.6 percent grade had been obtained in the preliminary tests. However, as lime grade increased, the recovery of lime decreased. This was attributed to the embedding of small siliceous particles in the lime constituents and the coating of the siliceous coal ash fraction with soluble lime. Tests have indicated that the lime may be liberated by attritional scrubbing and that carbonation and the use of chemical modifiers reduce coating of the siliceous coal ash fractions with lime. Employment of carbonation for pH and soluble lime control, modifiers for zeta potential control, agglomerate (emulsion) flotation and recleaning of the lime concentrates did not improve the yield and grade of lime to permit recovery of a majority of the lime in a highly concentrated form. (Author)