Use: complexing agent, masking agent, precipitant, reducing agent. The analysis is used for the verification and determination of beryllium, calcium, chromium, gold, manganese, strontium, thorium and other metal ions. Sodium and other elements were examined by picocrystalline analysis. Precipitate calcium, magnesium, thorium and rare earth elements. Standard solution for calibration of potassium permanganate and cerium sulfate solutions. Bleach. To dye. Also can be used to remove the rust on the clothing construction industry in the coating before the external wall coating, because of the strong alkalinity of the wall should first brush oxalic acid in addition to alkali. The pharmaceutical industry is used to produce aureomycin, oxytetracycline, streptomycin, borneol, vitamin B12, phenobarbital and other drugs. Printing and dyeing industry used as color aid, bleach agent, medical intermediates. Plastic industry used in the production of polyvinyl chloride, amino plastics, urea-formaldehyde plastics.