A Simple Dye Test for Mineral Powders
Powders are typical starting materials for the production of ceramics. In this paper, a strategy is presented, that allows a quick quality control of inorganic powders.
his strategy bases on dyes. Dye adsorption as well as the usage of indicators allow an easy and cheap characterisation of powders. Furthermore, the tests provide information on the chemical behaviour of the powders. It can be shown, that there is a coherence between the results of colour tests of a powder and the influence on the properties of ceramics (prepared from this powder).
Ceramic powders suffer from perpetual changes mainly by two reasons. First, due to their large surface powders show interactions with components of the atmosphere (e.g. water, carbon dioxide, oxygen). A further problem arises, if natural sources are the origin of powders: The material can have tremendous changes in the chemical composition causing serious problems in the production of ceramics. That’s why quality control of powders is a must. Unfortunately, the methods used are expensive and time consuming (e.g. BET, EDX, XPS, ICP). In particular, smaller companies have only limited opportunities to control the quality of their starting powders. In this paper a simple, quick and inexpensive method is suggested, which bases on dyes and allows a control of powder quality.