Oxalic acid[2]

Updated: 2026-09-15

Overview

Oxalic acid is an organic compound naturally found in plants like rhubarb and spinach, though industrial production typically involves chemical synthesis. It is a versatile chemical with applications spanning multiple industries due to its chelating and acidic properties. In B2B contexts, oxalic acid is primarily sourced in bulk for large-scale industrial processes. Its efficacy in removing rust and mineral deposits makes it indispensable in metal treatment, while its role in textile processing includes bleaching and dye fixation.

Physical and Chemical Properties

Oxalic acid exists as colorless crystals or a white powder with a sharp, acidic taste. It is dibasic, forming two series of salts (oxalates), and readily decomposes upon heating to release carbon monoxide and carbon dioxide. Its high solubility in polar solvents and ability to form stable complexes with metal ions (e.g., iron, calcium) underpin its industrial utility. However, these properties also necessitate careful handling to avoid equipment corrosion or unintended precipitation reactions.

Main Applications

Metal and mineral processing industries consume over 60% of global oxalic acid output, where it is used for descaling, ore extraction (e.g., rare earths), and electrolytic polishing. In textiles, it serves as a mordant and bleach for cotton and leather. Other niche uses include wood restoration (removing ink stains), API synthesis (e.g., antibiotics), and as a reducing agent in photographic developers. Emerging applications in battery recycling (lithium-ion) are gaining traction.

Safety and Storage

Oxalic acid is classified as harmful if swallowed (LD50 ~375 mg/kg rats) and causes severe skin burns. Always use chemical-resistant gloves (nitrile recommended) and ventilation to prevent dust inhalation. Store separately from alkalis and oxidizing agents to avoid violent reactions. Bulk storage tanks should be lined with polyethylene or glass-reinforced plastic to prevent corrosion. Spills require neutralization with lime or soda ash before disposal.

B2B Procurement Guide

Industrial buyers should prioritize suppliers offering batch-specific Certificates of Analysis (CoA) detailing purity, heavy metal content (<10 ppm), and moisture levels. Technical grade (99.6%) suits most applications, while pharmaceutical grades command premium pricing. Logistics considerations include moisture-proof packaging (double-layer PE bags) and compliance with transport regulations (UN 3261, Class 8). Long-term contracts with price adjustment clauses help mitigate market volatility linked to raw material (formic acid) costs.