|Chrome alumina pink ceramic colours.
N. S. Gopala Rao, Cent. Glass & Ceram. Res.
Inst. Bull., 5, 25 (1958).-Investigations
were carried out to study the effect of zinc
oxide, quartz, boric oxide, calcia and magnesia
on chrome alumina pink ceramic
colours. At calcination temperature of 1300°C
with 3 per cent potassium dichromate, some
of the successful pink colours were :
(i) Al.Oa 20, ZnO 40 and B30a 40-dark rose
pink, (ii) AbOa 20, ZnO 40, B20a 20 an4
Si02 17.23-dark rose pink and (iii) AlaOa
60, CaO 20, and B20a 20-brick red colour.
Calcia, added as calcium carbonate, though
not found to be necessary to produce pink
colour, was found to lower the required
temperature of calcination and to deepen
the colour. The best shades of pink were
obtained in the presence of zinc oxide, boric
oxide, calcia and quartz. Calcination at
temperatures higher than 1300°C was found
to deepen the colour with an optimum at
1450oC. Addition of 10 per cent red lead
lowered the calcination temperature and
deepened the colour.