Non-white roofing granules and methods of making same

Abstract

A plurality of non-white roofing granules is provided. The roofing granules include a plurality of particles including mineral fines and a calcia-based cement binder; and a non-white pigment-containing coating disposed on at least a portion of exterior surfaces of the particles. Methods of making the roofing granules are also provided. One method includes: mixing material including mineral fines and a calcia-based cement binder to provide agglomerates; curing the agglomerates to provide particles; and coating at least a portion of exterior surfaces of the particles with a non-white pigment-containing coating. Another method of making the roofing granules includes: providing an aqueous dispersion in a tool having cavities, the aqueous dispersion including mineral fines and a calcia-based cement binder; curing the aqueous dispersion in the tool to provide particles; and coating at least a portion of exterior surfaces of the particles with a non-white pigment-containing coating. The roofing granules exhibit an intrinsic total solar reflectance greater than 0.3. Often, the roofing granules contain by-product mineral fines.

Dependencies are inferred from the claim text.