Facile synthesis of nanostructured cobalt pigments by Co- A zeolite thermal conversion and its application in porcelain manufacture

An innovative and facile synthesis of cobalt based inorganic pigment was carried out by means of a low energy thermal conversion of a cobalt-exchanged zeolite. The Na-A [LTA] zeolite was used, since it is a low cost and easily available raw material. The ion exchange mechanism allowed to control, at microscopic level, the composition of the zeolitic precursor. Several chromatic effects could be obtained by varying the treatment temperature and/or the cobalt concentration in the contact solution. The reliability of these new zeolite-based pigments was tested in porcelain manufacture, in collaboration with the Institute for the Capodimonte porcelain “Giovanni Caselli”. The developed cobalt pigments were successfully tested either in the porcelain mixture to obtain a coloured product or in the decoration step (such as ingobbio, colored glazes and “third fire decoration”).