| 摘要 |
<p>The invention relates to a method of mixing incinerated sewage sludge ash (ISSA) and pulverised fuel ash (PFA) so as to produce a raw material suitable for producing building articles such as bricks, tiles or bloated aggregates. A problem with the incineration of sewage sludge to reduce the bulk prior to disposal, is that on incineration of the sludge, heavy metals normally present in raw sewage, are able to survive combustion and may subsequently be concentrated in the ash formed as a combustion residue. This has been undesirable from both an environmental and a health position. The present invention overcomes this problem by utilising a technique of entrapping such toxic species within the fired product, thereby minimising their release. Furthermore, because the heavy metals are entrapped within the bulk of the brick, slab or aggregate, they do not leach from the matrix of the building article and are therefore able to be used in a wider range of applications.</p> |
