| abstract |
The invention relates to a synthetically produced glass foam granules, foam glass, foam glass ballast or expanded glass. The glass foam granules, foam glass, foam glass gravel or expanded glass contains an addition of magnetizable material. The magnetizable material consists predominantly of ferromagnetic materials, such as iron, nickel or cobalt. The addition of magnetizable material is between 0.01 and 50 wt .-% and is homogeneously distributed in the glass foam granules or foam glass. A filter device (1) with a fluid-permeable housing (2) has molded bodies (6) of magnetizable glass foam granules or foam glass contained therein. An external electromagnetic field acts on the moldings (6) of magnetizable glass foam granules or foam glass. |