Oxalic Acid (systematic name: Ethanedioic Acid) is the simplest dicarboxylic acid. It appears as colorless transparent monoclinic crystals or white powder at room temperature, odorless and acidic in taste. As a strong organic acid (stronger than acetic acid), it possesses strong reducibility and corrosiveness, sublimes readily (starting at 100°C), and decomposes into carbon monoxide, carbon dioxide and water at high temperatures. For industrial export, it is usually supplied as dihydrate crystals or anhydrous powder with a purity of ≥99%, and is widely used in industrial cleaning, printing and dyeing, metallurgy and organic synthesis.

1. Metal cleaning and rust removal: Pickling, derusting and descaling of steel, stainless steel and semiconductor device surfaces.
2. Printing and dyeing & textiles: Used as a reducing agent, bleaching agent and mordant for bleaching cotton and linen fabrics and fixing dyes.
3. Rare earth extraction: Separation, extraction and purification of rare earth elements.
4. Organic synthesis: Manufacture of oxalates, oxalic acid esters, pharmaceutical intermediates and plastic additives.
5. Leather processing: Auxiliary for leather tanning and dyeing.
6. Daily cleaning: Removing scale (calcium and magnesium scale) from ceramic tiles, marble and sanitary ware.
7. Analytical reagent: Used in chemical titration, complexometric titration and as a standard reagent.