AbstractsChemistry

"The wide spread use of American kaolins and ball clays has been frowned upon by the majority of white-ware manufactures because the product resulting from their use in most cases has a color which is inferior to ware produced from English raw materials. This inferior color is generally attributed to the presence of a small amount of iron in the American clays. If some inexpensive chemical addition could be made which would eliminate the iron stain or in some way mask it, a wider market could be found in the white-ware industry for the domestic clays. One way to eliminate the iron would be to cause it to react with a chemical which would form an iron compound with a low volatization temperature, and so leave the body before it has a chance to combine with the clay ingredients to form silicates" – Introduction, p. 2.