|Monthly Tech-Tip |
Often ceramic clays are described on data sheets primarily by their chemistry (and requested as such). This is typically done at the expense of physical properties data. For example, Tapper clay is employed to plug the drain hole of ladles used to melt metals in the smelting industry. The operators of that equipment confront, in the physical presence of the material, many properties that have no relation to the chemistry (e.g. plasticity, shrinkage, water content). Notice also that the chemistry is not correct anyway, it species calcined material yet does not total 100. It specifies no carbon, yet this chemistry is like a ball clay, all of which have some carbon.
In ceramics, glazes and bodies have a chemistry, a mineralogy and a physical presence. All of these need to be understood to adjust and fix issues.
Tapper clay is used to seal the drain hole in melting vessels used in the smelting industries.