Refractory corrosion and stability

The attack of molten glass on refractory materials is of prime importance to both the glassmaker and refractory manufacturer. Over a period of several years we have developed what are now regarded as the standard tests for the assessment of refractory corrosion.

Two basic tests have been developed for the investigation of refractory attack, as follows:

Corrosion Test

This involves the production of a refractory finger by core drilling and diamond machining the refractory to a specific size. The test piece is suspended in molten glass, either for a specific period or until delineation between samples occurs and then carefully draining and measuring the wear at the flux-line. The test, although comparative in nature, allows assessment of the rate of attack, observation of reaction below the glass surface, the level of colouration of the glass and also the potential for the production of stone in the glass itself.

Bubble Potential

The second test performed in conjunction with the first is used to assess the level of bubble or seed released into the glass when it is in contact with the refractory material. This is a test that is especially useful for assessment of glass contact materials. A small refractory boat is cut from the refractory sample, again using diamond machining. This is filled with glass and heated up to melt the glass and allow the two materials to react. The sample is then cooled down and sectioned for examination using optical microscopy.

As well as the standard tests performed routinely for the majority of refractory suppliers, we can carry out various tests designed to highlight specific corrosion problems within the client's technology. Specialist analytical services are also available to further investigate the reaction products of these tests. This suite of techniques is particularly useful for the investigation of penetration reactions and preliminary identification of the phase chances that may occur as a result of glass penetration.

A range of other tests is also available to determine properties such as density, real and apparent porosity, permanent linear change of shape and exudation at temperature

It is this flexibility of testing methods that provides the opportunity to maximise the information gained from any series of tests carried out.

Please contact us, or make an enquiry using the form above, if you have any bespoke requirements, require further information, or would like a quote for analysis.


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