EFFECT OF SOLUBLE SALTS ON THE PROPERTIES OF ENAMELS1

Abstract

ABSTRACTEnamels, in common with other types of glasses, are more or less soluble in water, depending on their compositions. The nature and quantity of salts dissolved from the enamel glass during milling have a very definite bearing on the suspension, work ability, and other properties of the enamel, such as pitting and crawling.Those enamels which produce mill liquors which are excessively alkaline have very poor floating qualities. The ratio of free alkali to boric oxide dissolved from the enamel frit is an important factor in the flotation properties of the enamel.The poor floating powers of certain enamels can be corrected by the addition of suitable electrolytes. The kind and quantity of salts dissolved from the frit will determine the selection of the proper electrolyte. Enamel compositions having minimum solubility for good suspension and other properties are given.The value of an enamel clay cannot be determined by floating the clay in water. Tests must be made with the clay in the type of enamel with which it is to be used.Any studies on the effect of aging of enamels on their working properties must give consideration to the constitution and quantity of the individual salts dissolved from the enamel frit, and to the action of carbon dioxide in neutralizing part of the free alkali.