ALUMINA OR MULLITE-BASED PIGMENTS MADE FROM WASTES OR NATURAL SUB-PRODUCTS

摘要

Wastes or natural sub-products have been used to prepare alumina or mullite based materials. Among these, sludge, generated from Al-rich anodising or surface treatments, diatomite and clay-based rejects from sand mining, are representative examples. Our research was firstly devoted to the fabrication of refractory or electrical nsulating recycled materials (e.g., substrates, crucibles). The final materials also have compositions adequate to act as matrixes for transition metals incorporation. In such way, ceramic pigments can be produced, by using pure chemical-grade reagents or metals-containing residues (e.g. metal-plating sludge) as colouring agents. This work details the preparation of several pigments based on mullite and alumina matrixes. Typical working conditions and colour development on different glazes are reported.