The effect of water on maleic acid and salicylic acid extractions

Abstract

Contamination of methanol by water was evidenced by the occurrence of ettringite in residues of cement extracted using a solution of maleic acid in methanol. Therefore, an analytical method was developed to determine water contents, based on the reaction of 2,2-dimethoxypropane with water, which forms acetone and methanol. Methanol analyzed by this method was found to contain as much as 2 percent H 2O. Thus it is necessary to use freshly dried methanol for extracting the silicates from cement or clinker. However, it was found that removal of all water causes the solution of maleic acid in methanol to gel when the cement or clinker is added, and the salicylic acid procedure is thus preferred because it does not form such a gel. It was shown that methanol containing levels of water as low as 0.5 percent will cause loss of water-soluble phases from cement or clinker.