Iron-alumina-lime-potassium carbonate

The impurities most frequently met with in solution of and solid hydrate of potassa are carbonate of lime oxide of iron, silica, alumina, carbonate and sulphate of potassa, and chloride of potassium. > Carbonic acid is indicated by effervescence on the addition of an acid. Carbonate of lime and oxide of iron remain insoluble when the salt is treated with water. Silicic acid and... 

In the manufacture of glass wool, the raw materials are those usually used in the glass industry i.e. sand, lime, dolomite, feldspar, kaolin, alumina-containing volcanic rocks, sodium carbonate, sodium sulfate, potassium carbonate and boron minerals. The purity requirements particularly as regards iron content are not particularly high. 

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