Industrial-grade Citric acid

Citric acid is an organic acid produced by Aspergillus niger fermentation from starchy or saccharide raw materials such as corn and cassava. It is widely used in the food, chemical, electroplating, cleaning, pharmaceutical and environmental protection industries. Its core value lies in the combination of acidity, chelating ability and buffering capacity, and it serves as a pH regulator, metal complexing agent, descaling agent and antioxidant in industrial applications.

Citric acid is a common organic compound with the chemical formula C₆H₈O₇. It can be produced from lemon juice and dilute sulfuric acid. In the food industry, citric acid is widely used as a food additive in beverages, desserts, dairy products, biscuits, and other foods to enhance their aroma.

Citric acid also has various applications in industry. For example, it is used as a pesticide to inhibit microbial growth, acts as a treatment agent to suppress industrial impurities, improves the curing properties of coatings, enhances the stability of phosphate agents, increases the fluidity of fillers and pigments, and improves the moisture resistance and strength of paper. It is even used in the insulation materials industry within the electronics sector.

Main Applications:

1. Water treatment: Used as a scale inhibitor and water softener, it chelates calcium, magnesium and other metal ions in water to prevent scale formation in pipelines and equipment.
2. Metal cleaning: Serves as a mild rust remover and surface conditioner, which can strip oxide layers on metal surfaces without causing excessive corrosion to the substrate.
3. Textile printing and dyeing: Acts as a pH regulator and chelating agent in the dyeing process, improving dye fixation rate and fabric color fastness.
4. Plastic processing: Applied as a plasticizer precursor and polymerization regulator, helping to optimize the mechanical properties of plastic products.
5. Detergent production: Used as a builder in detergent formulas, enhancing the decontamination efficiency and preventing the re-deposition of dirt.

The mechanism of action of industrial-grade citric acid is based on the three carboxyl groups (–COOH) in its molecular structure, which endows it with the following chemical behaviors:
1. Descaling reaction: It undergoes acid-base neutralization and complexation reactions with calcium carbonate (CaCO₃), the main component of scale, to generate soluble calcium citrate, water and carbon dioxide. This reaction leaves no residue and does not corrode stainless steel, making it suitable for the chemical cleaning of boilers, heat exchangers and shower equipment.
2. Metal chelation: Its molecules can form stable six-membered ring complexes with metal ions such as Fe³⁺, Cu²⁺ and Ni²⁺, preventing metal ions from precipitating in electroplating solutions or redepositing on fabric surfaces during the washing process, thus improving cleaning efficiency.
3. pH buffering: As a weak organic acid (pKa₁=3.13, pKa₂=4.76, pKa₃=6.40), it has excellent buffering capacity in the pH range of 3–6, and is commonly used in electroplating solutions, pharmaceutical buffer systems and flue gas desulfurization (citric acid-sodium citrate system).
4. Biological effects: In feed, it can lower intestinal pH, inhibit harmful bacteria and promote the absorption of calcium and phosphorus; in sewage treatment, it can act as a biodegradable alternative chelating agent.

Product Name: Citric Acid
Product Grade: Industrial Grade
Product Specification: 25kg/bag
Product Purity: 99%
Product Appearance: White crystalline powder
Storage Method: Store in a cool and sealed place

1. High Water Solubility: Easily soluble in water and ethanol. At 20℃, the solubility of monohydrate citric acid in water is about 147g/100mL, while that of anhydrous citric acid is about 154g/100mL. The dissolution process is accompanied by endothermic cooling.
2. Mild Acidity: It has moderate acidity strength (pKa₁=3.13). Compared with inorganic acids such as hydrochloric acid and sulfuric acid, it has lower corrosivity to metal equipment and higher operational safety.
3. Excellent Chelating Performance: It has strong chelating ability for polyvalent metal ions, especially suitable for chelating calcium and magnesium ions. It features a high chelation stability constant and can function effectively over a wide pH range (2-8).
4. Eco-friendly and Biodegradable: It has a high biodegradation rate and can be completely degraded under aerobic conditions without toxic residues. It complies with the EU REACH Regulation and environmental discharge standards.
5. Good Compatibility: It can be compounded with surfactants, alkaline substances, oxidants, etc., without generating precipitates or harmful substances, and is widely used in composite formulation systems.