Granules for solar absorber for use in e.g. solar collector

摘要

The granules for solar absorber consist of foamed glass coloured or coated with cobalt oxide. Also claimed is a method fro producing the granules. A mixture of ground glass, blowing agent and binder is granulated, and the granules are dried. They are then coated with a cobalt compound and then with separating agent as well as a foam. The separating agent is removed to expose the cobalt oxide layer and leave no residue.