RECYCLED MATERIAL FROM THE VITRIFICATION OF ASBESTOS-CONTAINING-WASTES TO BE USED AS HIGH TEMPERATURE THERMAL STORAGE MATERIAL

摘要

The purpose of the present work is to study ceramic materials obtained by industrial vitrification of asbestos containing wastes (ACW) as candidate to be used as high temperature sensible heat thermal storage materials in concentrated solar power processes. The methods used to measure the major properties of the material (needed for its comparison to conventional storage materials) are: Archimedean method for density, calorimetry for sensible heat and thermal behavior, SEM and XRD for structural description, flash diffusivity for thermal conductivity, thermal expansion and young modulus for mechanical behavior. According to those methods, the main obtained results are (from room to 1000℃): a density 3of 3100 kg/m, a sensible heat from 800 to 1034 J/(kg K), a thermal conductivity from 2 to -6 -1 1.5 W/(m K), a thermal coefficient of expansion of 8.8 10Kand a young modulus of 110. As main conclusions, the ACW ceramics have been found to be good candidates for high temperature sensible heat thermal storage. Up to 1000℃, their thermal behavior is very stable, their thermal and mechanical properties similar to those of commercial refractory ceramics known to be currently 1000 times more expensive. A natural stone, namely the quartzite, has been also studied for comparison. This material presents similar storage capacity and larger thermal conductivity (from 2 to 7 W/(m K)) but does not withstand heating treatment without breaking. Therefore, due to its thermal behavior, the quartzite could not be used as high temperature thermal storage material.