The obtained results indicate that there is a very considerable potential for the use of cement-asbestos waste as a useful secondary raw material in the production of clinker ceramics and that it can be used to substitute quartz sand or clay-chamotte. The obtained ceramic materials have very good properties and features which allow us to classify such materials as clinker ceramic products with low water absorption, high compressive strength and full frost resistance. The proposed solution may indicate and open up a new way for disposal and utilisation of hazardous wastes containing
asbestos-like cement-asbestos.
The use of ceramic masses with a reduced amount of mixing water (dry ceramic masses) and thereby forming via the pressing method eliminates the formation of unfavourable efflorescence on the surface of the ceramics. Moreover, it contributed to negligible changes during the drying process, so consequently this solution could facilitate the control and produce of clinker ceramic materials.
However, the waste form introduced to the ceramic mass is very important, especially for a lower firing temperature.
Cement-asbestos that is raw or pre-calcined at 700 C favours better sintering of the material. The obtained ceramics are characterised by smaller values of water absorption, especially for the lower firing temperature. On the other hand, treatment of a raw cement-asbestos waste will generate new environmental problems and, consequently, new technical safeguards should be implemented. The use of asbestos wastes pre-calcined at 1200 C gives clinker materials with better compressive strength, but this solution requires preliminary heat treatment in a relatively high temperature.