... like caustic soda in different purities and appearances (96%,99% and flakes, solid,peals); anhydrous sodium sulfite, ... Uses: Primarily used as the filler of dyes and auxiliaries agents, and as the ... accelerating agent of direct dyes, sulfur dyes and vat dyes ... synthetic fiber, leather and other industries. ItemStandardResultsNa2SO4 ≥99%99.21%Fe≤0.002%0.002%Insoluble solid ...