Development of layer structured wave absorbing mineral wool boards for indoor electromagnetic radiation protection

•Layer structured mineral wool boards for electromagnetic wave absorbing were devised.•The double layer sample can attenuate 90% incident wave in 2–18 GHz.•Effect of the special interior structure on wave absorption was analyzed.•This study provides a high-performance wave absorbing building materials.

To prevent and control the severe indoor electromagnetic radiation and obtain a broadband wave absorbing material for constructional engineering, layer structured mineral wool boards with carbon black (CB) absorbent were devised and fabricated, and the reflection loss was studied in the frequency ranges of 2–18 GHz. The morphology, microstructure and electromagnetic characteristics of mineral wool and CB were studied by scanning electron microscopy, transmission electron microscopy and vector network analyzer, respectively. When the single-layer mineral wool board contains 3% CB, the reflection loss is less than −10 dB (90% electromagnetic wave is attenuated) in the frequency ranges of 2–3 and 7–18 GHz. The reflection loss of double-layer mineral wool board is under −10 dB in the whole frequency ranges of 2–18 GHz. The results show that the interior structure of the mineral wool board is benefit to the absorption property, and the design of double-layer structure can further improve the absorbing property.