Reduced pressure distillation method for determining the acetic acid salt in sodium silicate sand

Abstract

The residual acetate in sodium silicate sand and regenerated sand has an important influence on the performance. This paper presents a method to separate and determine the residual acetic acid in the used sand. Using sulfuric acid solution as solvent, acetic acid generated by acetic acid was extracted by decompression distillation. The content of acetic acid was determined by titration, and the content of acetate was determined by titration. On the basis of single factor test, the extraction conditions were optimized by using four factors of orthogonal test, and the optimum extraction process was determined. The best extraction technology: distillation temperature 100 °C, 50 min distillation time, solvent concentration 1.0 mol/L, vacuum pressure 0.06 MP. The method is used to determine the content of acetic acid in the sample of water sodium silicate sand, the measured value is consistent with the theoretical value, and RSD is less than 1.1 %. The determination of the content of acetic acid in the old sand and regenerated sand of sodium silicate was measured, and the measured value was in line with the measured value of the extraction method, and RSD was less than 1.3 %. This study lays the foundation for evaluating the performance of sodium silicate sand and recycled sand.