Alexander Baldus

Cobalt savings in roofing tile glazes with new developments of black colour frits

Rising cobalt prices are making dark glazes and engobes more expensive. The clay roofing tile industry is particularly affected, as these colours are very popular. In a glaze development, the cobalt-containing pigment part of the recipe was removed, and a less expensive black body pigment was added. A direct comparison with the standard glaze showed an identical result, which was confirmed by measurements with a colorimeter.

1 Problem definition

Owing to a very high cobalt price and its fluctuations, caused in particular by the high and increasing demand for cobalt in electric mobility, the prices for glazes and engobes in the ceramic sector have risen steadily in recent years or fluctuated very widely depending on the daily price of the cobalt. As a result, the very popular dark (black) colours on the market have become very price-intensive, which is noticeable for the producers of glazes and engobes, the roofing tile manufacturers and the end user.

2 Objectives and experimental idea

The intention of a development...

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